Ecological Succession Research Papers - Academia.edu (original) (raw)

The cockroach gut harbors a wide variety of microorganisms that, among other functions, collaborate in digestion and act as a barrier against pathogen colonization. Blattabacterium, a primary endosymbiont, lives in the fat body inside... more

The cockroach gut harbors a wide variety of microorganisms that, among other functions, collaborate in digestion and act as a barrier against pathogen colonization. Blattabacterium, a primary endosymbiont, lives in the fat body inside bacte-riocytes and plays an important role in nitrogen recycling. Little is known about the mode of acquisition of gut bacteria or their ecological succession throughout the insect life cycle. Here we report on the bacterial taxa isolated from different developmental instars of the cockroach Blattella germanica. The bacterial load in the gut increased two orders of magnitude from the first to the second nymphal stage, coinciding with the incorporation of the majority of bacterial taxa, but remained similar thereafter. Pyrose-quencing of the hypervariable regions V1–V3 of the 16S rRNA genes showed that the microbial composition differed signifi-cantly between adults and nymphs. Specifically, a succession was observed in which Fusobacterium accumulated w...

We use the analogy of ecological succession as our conceptual framework. We apply this analogy to the history of foreign banks in Bulgaria and argue that the current predominance of foreign banks is unlikely to be permanent, even without... more

We use the analogy of ecological succession as our conceptual framework. We apply this analogy to the history of foreign banks in Bulgaria and argue that the current predominance of foreign banks is unlikely to be permanent, even without government action. Foreign banks have entered Bulgaria several times-before World War I, again after that war, and after the fall of Communism in the early 1990s. The same source countries and even some of the same banks that were present before World War II or even World War I, reappear in the 1990s. Government concern with retaining control over credit limited the foreigners' role in the banking system. However, since 1997 the government has privatized almost all the major banks with the result that foreign banks now control over 80 per cent of the banking system's assets.

Mangroves play an important role in coastal zones in many aspects e.g. extremely essential habitats for many species, coastlines protection from natural hazards, and so on. However, in Vietnam, like in other developing countries, these... more

Mangroves play an important role in coastal zones in many aspects e.g. extremely essential habitats for many species, coastlines protection from natural hazards, and so on. However, in Vietnam, like in other developing countries, these mangrove areas have been destroyed and encroached as a consequence of a poorly planned economic development.

The recurrence of fires has increased considerably due to human activity, affecting even forests where traditionally fire is uncommon. In this study, we verify the effects of degradation caused by fire in the Canarian laurel forests,... more

The recurrence of fires has increased considerably due to human activity, affecting even forests where traditionally fire is uncommon. In this study, we verify the effects of degradation caused by fire in the Canarian laurel forests, which is a subtropical forest formation restricted to the humid montane areas of these Macaronesian islands. We evaluated the effect of fire by comparing a series of burned plots corresponding to fires from 1960, 1984, 1995, to 2012 with geographically proximate and comparable unburned plots in the Garajonay National Park (La Gomera Island, Spain). We focused on three aspects that are immediately altered by fire: forest structure, floristic composition, and microclimate. These aspects have been quantified using (a) tree density , the Pielou index using tree height classes, and DBH for the vertical structure of the forest; (b) DCA, the Bray Curtis dissimilarity index, and a species indicator analysis for the floristic composition; and (c) temperature and relative humidity for microcli-mate under three canopy cover conditions. Our results reveal that, overall, structural complexity and its composition in the burned areas have barely reached 40% and 35%, respectively, when compared with unburned areas, and recovery mainly depends on time since fire. Additionally, burned plots presented more pioneer species, a higher density of trees, and climatic variables tend to have a wider range throughout the day. These data reveal the long time span that this ecosystem needs for recovery to a prefire state and how it may be more prone to subsequent fire events. KEYWORDS forest structure and diversity, laurel forest, microclimate, natural regeneration, postfire succession

Estuaries represent highly dynamic environments, especially with respect to salinity. Exploitation of these habitats by marine species can assist their ecological success, however they require specialized behavioral strategies as well as... more

Estuaries represent highly dynamic environments, especially with respect to salinity. Exploitation of these habitats by marine species can assist their ecological success, however they require specialized behavioral strategies as well as physiological abilities to cope with the fluctuations of physical stressors. The Valdivia River estuary, southern Chile, is a site of high larval recruitment and juvenile abundance of the commercial crab species Cancer edwardsii, particularly during the spring and summer months. This estuary experiences severe low salinity events (b7.5) for periods exceeding 6 h, that are associated with rainfall events and the subsequent higher flow rates of the tributaries. To determine the strategies employed by juvenile crabs living in the inner portions of the estuary in the face of changes in salinity conditions, we evaluated their survival and behavioral responses when exposed to a salinity gradient. Early juveniles were incubated at salinities of 0, 7.5, 15-22.5, 32 and crab mortality was recorded after 1, 6 and 12 h of exposure. In addition, early juveniles were experimentally exposed to continuous and gradual changes in saline conditions to evaluate their behavior, which was recorded on video. The main results were (1) despite most Cancer species being considered weak osmoregulators, 30% of individuals of C. edwardsii were able to survive freshwater conditions for 12 h. (2) burying and not quiescence behavior was associated with a drop in salinity, (3) in severe hyposaline conditions, the crabs increased their survival burying in the substrate, probably using higher salinity (N 22) interstitial water. Our findings suggest that burying behavior plays a key role in allowing the crabs inhabit inner estuarine areas where sudden and unexpected severe hyposalinity events occur.

All species in the genus Cyperus (Cyperaceae) that occur in temperate eastern North America were assigned to either the C 3 or C 4 photosynthetic pathway using leaf anatomical characteristics and stable carbon isotope ratios. Of the 39... more

All species in the genus Cyperus (Cyperaceae) that occur in temperate eastern North America were assigned to either the C 3 or C 4 photosynthetic pathway using leaf anatomical characteristics and stable carbon isotope ratios. Of the 39 species in the study area, 32 had C 4 photosynthesis while 7 had C 3 . The numbers of C 3 , C 4 , and total Cyperus species were significantly and positively correlated with both summer precipitation and mean annual temperature. However, the proportional abundance of C 4 species within Cyperus was not significantly related to either climatic variable. The highest Cyperus diversity was found on the Atlantic Coastal Plain, a pattern that remained after climatic differences between regions were accounted for. All the C 3 species and the majority of the C 4 species were restricted to wetlands or damp soil habitats; 13 of the 32 C 4 species occurred in dry, sandy habitats. Given that the C 3 pathway is ancestral in the genus Cyperus, it appears that C 4 photosynthesis evolved in a wetland context for this genus. We suggest that the high nitrogen use efficiency associated with the C 4 pathway is largely responsible for the evolution and ecological success of C 4 Cyperus species in infertile, temperate wetlands.

Although ecological succession is one of the principal focuses of recent restoration ecology research, it is still unclear which factors drive this process and positively influence species richness and functional diversity. In this study... more

Although ecological succession is one of the principal focuses of recent restoration ecology research, it is still unclear which factors drive this process and positively influence species richness and functional diversity. In this study we sought to elucidate how species traits and functional diversity change during forest succession, and to identify important factors that determine the species in the observed assemblages. We analyzed species richness and functional diversity of ground beetle assemblages in relation to succession on post-industrial localities after habitat deterioration caused by spoil de-position. We selected ground beetles as they are known to be sensitive to landscape changes (with a large range of responses), and their taxonomy and ecology are generally well-known. Ground beetles were sampled on the spoil heaps during the last 30 years when spontaneous succession occurred. To calculate functional diversity, we used traits related to habitat and trophic niche, i.e. food specialization, wing morphology , trophic level, and bio-indication value. Ground beetle species were found to be distributed non-randomly in the assemblages in the late phase of succession. Ordination analyses revealed that the ground beetle assemblage was significantly associated with the proportion of forested area. Environmental heterogeneity generated assemblages that contained over-dispersed species traits. Our findings indicated that environmental conditions at late successional stages supported less mobile carnivorous species. Overall, we conclude that the decline in species richness and functional diversity in the middle of the studied succession gradient indicated that the assemblages of open habitats had been replaced by species typical of forest ecosystems.

Leaf-level photosynthetic-light response and plant-level daily carbon gain were estimated for seedlings of moderately shade-tolerant yellow birch (Betula alleghaniensis Britton) and shade-tolerant sugar maple (Acer saccharum Marsh.) and... more

Leaf-level photosynthetic-light response and plant-level daily carbon gain were estimated for seedlings of moderately shade-tolerant yellow birch (Betula alleghaniensis Britton) and shade-tolerant sugar maple (Acer saccharum Marsh.) and beech (Fagus grandifolia Ehrh.) growing in gaps and under a closed canopy in a sugar maple stand at Duchesnay, Que. All three species had a higher photosynthetic capacity (A max ) in the gaps than in shade, but yellow birch and beech responded more markedly than sugar maple to the increase in light availability. The high degree of plasticity observed in beech suggests that the prediction that photosynthetic plasticity should decrease with increasing shade tolerance may not hold when comparisons are made among a few late-successional species. Unit-area daily carbon gain (C A ) was significantly higher in the gaps than in shade for all three species, but no significant difference was observed between light environments for plant-level carbon gain (C W ). In shade, we found no difference of C A and C W among species. In gaps, beech had a significantly higher C A than sugar maple but similar to that of birch, and birch had a significantly higher C W than maple but similar to that of beech. Sugar maple consistently had lower carbon gains than yellow birch and beech but is nevertheless the dominant species at our study site. These results indicate that although plant-level carbon gain is presumably more closely related to growth and survival of a species than leaf-level photosynthesis, it is still many steps removed from the ecological success of a species.

A revival in the concept of sustainability is appreciated as Earth's human population continues to increase and its related global concerns in disease ecology, energy resource management, environmental literacy, food production, genetic... more

A revival in the concept of sustainability is appreciated as Earth's human population continues to increase and its related global concerns in disease ecology, energy resource management, environmental literacy, food production, genetic diversity, and landscape vitality continue to magnify. Sustain is defined within this paper as to keep in existence or to supply with resources or necessities to prevent from falling below a given threshold of health or vitality. Barrett et al. (Bioscience 47:531-535, 1997) illustrated how seven (7) processes (behaviour, development, diversity, energetics, evolution, integration, regulation) transcend eleven (11) levels of ecological organization, ranging from the ecosphere to the cellular. Comprehension of how these processes transcend all levels of ecological organization allow programs and initiatives (e.g. preserving biotic diversity) to be defined by informed incentive, rather than regulatory mandate, within societal systems. We describe how the integration of an eighth transcending process-aesthetics-is essential in the approach to and managing of market and nonmarket capital necessary in sustaining societies.

In Belgium a long process (1999)(2000)(2001)(2002)(2003)(2004)(2005) led to the designation of several marine protected areas (MPAs). In order to analyse the designation process, the 'policy arrangement approach' was used as an analytical... more

In Belgium a long process (1999)(2000)(2001)(2002)(2003)(2004)(2005) led to the designation of several marine protected areas (MPAs). In order to analyse the designation process, the 'policy arrangement approach' was used as an analytical tool. Attention was given to four dimensions (actors and coalitions, arguments, rules and resources). Particular attention was paid to the switch from an authoritative to a more deliberated policy style in reaction to conflicts with stakeholders. This switch in policy style contributed to a successful legal designation, but does not guarantee the best protection of marine biodiversity. This case study linked science (setting ecological goals) to policy (analysis of a policy process) and led to some more general conclusions on the designation of MPAs and the role of participation in this process.

The microbial populations in the loose outer corrosion layer "OCL# and the bound inner corrosion layer "ICL# of concrete from a corroded sewage collection system were enumerated[ Chemical and physical studies were performed to determine... more

The microbial populations in the loose outer corrosion layer "OCL# and the bound inner corrosion layer "ICL# of concrete from a corroded sewage collection system were enumerated[ Chemical and physical studies were performed to determine the mineralogical composition strength of the samples[ The average number of acidophilic sulphur!oxidizing microorganisms "ASOM# found were 03\499 and 05\999 MPN:g "OCL# and 01\499 and 099 MPN:g "ICL# at the crown and springline[ The average numbers of neutrophilic sulfur!oxidizing microorganisms "NSOM# found were 097\999 and 003\999 MPN:g "OCL#\ and 4 and 299 MPN:g "ICL# at the crown and the springline[ The average compressive strength of the concrete undergoing corrosion was reduced by 19)[ The results suggest that an initial ecological succession occurred on the concrete surface and that the progression of the corroding front into the concrete was controlled by the penetration of acid produced by ASOM followed by the ASOM themselves[ NSOM did not appear to penetrate the concrete[ Þ 0887 Elsevier Science Ltd[ All rights reserved

The present study compares the soil chemical properties of a new burnt site and an old burnt site, which had experienced three and one ®re(s) respectively since 1988. The new burnt site is presently reduced to grassland and the old burnt... more

The present study compares the soil chemical properties of a new burnt site and an old burnt site, which had experienced three and one ®re(s) respectively since 1988. The new burnt site is presently reduced to grassland and the old burnt site to mixed grassland/scrubland. Repeated ®res raised soil pH by 0.27±0.33 units, exchangeable H and K the old burnt site. Fire similarly reduced the effective cation exchange capacity (ECEC) and the base saturation by 85% and 90%, respectively. The occurrence of successive ®res is therefore hazardous to the environment and in the absence of ®re for 6 years the old burnt site has accumulated suf®cient organic matter and nitrogen needed for the invasion of the more nutrient-demanding tree species. The selection of tree species and site preparation pertaining to enhancement planting of the ®re-disturbed slopes to accelerate forest development are discussed. #

The distribution of phytoplankton abundance, biomass and species composition coupled with environmental factors and metazooplankton was studied relatively intensively and over a period of four consecutive years in five ponds featuring a... more

The distribution of phytoplankton abundance, biomass and species composition coupled with environmental factors and metazooplankton was studied relatively intensively and over a period of four consecutive years in five ponds featuring a gradient of increasing salinity from near to that of sea water to a nine-fold concentration from 2000 to 2003. The results indicate that the physical characteristics of the water (temperature and salinity) were quite similar over the years. Nutrients, which were concentrated in pond A1, decreased with increases in salt concentration. The composition of the phytoplankton community showed strong seasonality. Diatoms dominated in the first ponds A1, A16 and C2-1, followed by dinoflagellates. Chlorophyceae dominated the phytoplankton community in the hypersaline ponds M2 and TS. Cyanobacteriae were relatively abundant in ponds M2 and TS. The highest phytoplankton density and biomass were found in the ponds with the highest salinity due to the proliferation of Dunaliella salina (Chlorophyta: Volvocales). The inter-annual study of phytoplankton succession in the Sfax solar salterns showed slight differences among the years of study due to the stability of the environmental conditions. Phytoplankton communities were permanently primitive, stage 1 e structured as they failed to build complexity because of salt stress which operates for longer and above any other variables. This reduced frequency of disturbance to the existing course of regulation, allowed the community to "mature" from its "primitive" state, rather than experience frequent structural setbacks.

The paper considers the geographies of scientific knowledge produced around a pool dug at Long Gores, Hickling, Norfolk, England in 1953. Designed by ecologist and artist Marietta Pallis as a swimming pool and symbolic site, the pool also... more

The paper considers the geographies of scientific knowledge produced around a pool dug at Long Gores, Hickling, Norfolk, England in 1953. Designed by ecologist and artist Marietta Pallis as a swimming pool and symbolic site, the pool also became a scientific experiment in landscape, through which Pallis pursued general ecological principles and specific theories on the landscape history and ecology of the Norfolk Broads. The digging of the pool coincided with the publication of research establishing the broads' artificial origin in medieval peat diggings. The paper begins by developing arguments concerning the cultural geographies of scientific knowledge. We then trace Pallis's presentation of the pool as equivalent for the broads in its origins and development, her discussion of the relationship between pool, marsh and North Sea, the connection between Pallis and local scientific culture, and the pool's place in a landscape of ecological succession. The paper concludes with further theoretical discussion, and reflection on the remains of Pallis and her reputation.

Polar seaweeds are strongly adapted to the low temperatures of their environment, Antarctic species more strongly than Arctic species due to the longer cold water history of the Antarctic region. By reason of the strong isolation of the... more

Polar seaweeds are strongly adapted to the low temperatures of their environment, Antarctic species more strongly than Arctic species due to the longer cold water history of the Antarctic region. By reason of the strong isolation of the Southern Ocean the Antarctic marine flora is characterized by a high degree of endemism, whereas in the Arctic only few endemic species have been found so far. All polar species are strongly shade adapted and their phenology is finely tuned to the strong seasonal changes of the light conditions. The paper summarises the present knowledge of seaweeds from both polar regions with regard to the following topics: the history of seaweed research in polar regions; the environment of seaweeds in polar waters; biodiversity, biogeographical relationships and vertical distribution of Arctic and Antarctic seaweeds; life histories and physiological thallus anatomy; temperature demands and geographical distribution; light demands and depth zonation; the effect of salinity, temperature and desiccation on supraand eulittoral seaweeds; seasonality of reproduction and the physiological characteristics of C. Wiencke (&) AE U. H. Lü der microscopic developmental stages; seasonal growth and photosynthesis; elemental and nutritional contents and chemical and physical defences against herbivory. We present evidence to show that specific characteristics and adaptations in polar seaweeds help to explain their ecological success under environmentally extreme conditions. In conclusion, as a perspective and guide for future research we draw attention to many remaining gaps in knowledge.

After a millenarian history of overexploitation, most forests in the Mediterranean Basin have disappeared, leaving many degraded landscapes that have been recolonized by early successional shrub-dominated communities. Common reforestation... more

After a millenarian history of overexploitation, most forests in the Mediterranean Basin have disappeared, leaving many degraded landscapes that have been recolonized by early successional shrub-dominated communities. Common reforestation techniques treat these shrubs as competitors against newly planted tree seedlings; thus shrubs are cleared before tree plantation. However, empirical studies and theory governing plantplant interactions suggest that, in stress-prone Mediterranean environments, shrubs can have a net positive effect on recruitment of other species. Between 1997 and 2001, we carried out experimental reforestations in the Sierra Nevada Protected Area (southeast Spain) with the aim of comparing the survival and growth of seedlings planted in open areas (the current reforestation technique) with seedlings planted under the canopy of preexisting shrub species. Over 18 000 seedlings of 11 woody species were planted under 16 different nurse shrubs throughout a broad geographical area. We sought to explore variation in the sign and magnitude of interactions along spatial gradients defined by altitude and aspect. In the present work, we report the results of a meta-analysis conducted with seedling survival and growth data for the first summer following planting, the most critical period for reforestation success in Mediterranean areas. The facilitative effect was consistent in all environmental situations explored (grand mean effect size d ϩ ϭ 0.89 for survival and 0.27 for growth). However, there were differences in the magnitude of the interaction, depending on the seedling species planted as well as the nurse shrub species involved. Additionally, nurse shrubs had a stronger facilitative effect on seedling survival and growth at low altitudes and sunny, drier slopes than at high altitudes or shady, wetter slopes. Facilitation in the dry years proved higher than in the one wet year. Our results show that pioneer shrubs facilitate the establishment of woody, late-successional Mediterranean species and thus can positively affect reforestation success in many different ecological settings.

Synopsis This article derives from a society-wide symposium organized by Timothy Bradley and Adriana Briscoe and presented at the 2009 annual meeting of the Society for Integrative and Comparative Biology in Boston, Massachusetts. David... more

Synopsis This article derives from a society-wide symposium organized by Timothy Bradley and Adriana Briscoe and presented at the 2009 annual meeting of the Society for Integrative and Comparative Biology in Boston, Massachusetts. David Grimaldi provided the opening presentation in which he outlined the major evolutionary events in the formation and subsequent diversification of the insect clade. This presentation was followed by speakers who detailed the evolutionary history of specific physiological and/or behavioral traits that have caused insects to be both ecologically successful and fascinating as subjects for biological study. These include a review of the evolutionary history of the insects, the origins of flight, osmoregulation, the evolution of tracheal systems, the evolution of color vision, circadian clocks, and the evolution of eusociality. These topics, as covered by the speakers, provide an overview of the pattern and timing of evolutionary diversification and specialization in the group of animals we know as insects.

During the Early Pleistocene, hominins dispersed from Africa to Eurasia via the Levant. The presence of African taxa in higher latitudes has been interpreted as indicative of an Africa savanna habitat in the Early Pleistocene of the... more

During the Early Pleistocene, hominins dispersed from Africa to Eurasia via the Levant. The presence of African taxa in higher latitudes has been interpreted as indicative of an Africa savanna habitat in the Early Pleistocene of the Levant and as support for the hypothesis that the spread of grasslands into higher latitudes promoted the dispersal of hominins into Eurasia. To infer the paleoenvironment of the Levant during the Early Pleistocene, a multivariate analysis based on abundance and presence-absence data of mesoherbivores was used. Results indicate that in the Early Pleistocene, the Levant was situated in a Mediterranean woodland habitat. The presence of African taxa in novel environments may be explained using a long distance dispersal model and suggests that the spatial and temporal abundance pattern of African taxa in the Levant is consistent with the early stages of dispersal and is not indicative of the presence of savanna habitats in higher latitudes. The ecological success of hominins in higher latitudes as attested to by their widespread geographic distribution is consistent with their adaptation to novel environments and suggests that they may have been pre-adapted to variable environments.

In the final analysis, sustainable agriculture must derive from applied ecology, especially the principle of the regulation of the abundance and distribution of species (and, secondarily, their activities) in space and time. Interspecific... more

In the final analysis, sustainable agriculture must derive from applied ecology, especially the principle of the regulation of the abundance and distribution of species (and, secondarily, their activities) in space and time. Interspecific competition in natural ecosystems has its counterparts in agriculture, designed to divert greater amounts of energy, nutrients, and water into crops. Whereas natural ecosystems select for a diversity of species in communities, recent agriculture has minimized diversity in favour of vulnerable monocultures. Such systems show intrinsically less stability and resilience to perturbations. Some kinds of crop rotation resemble ecological succession in that one crop prepares the land for successive crop production. Such rotations enhance soil organic processes such as decomposition and material cycling, build a nutrient capital to sustain later crop growth, and reduce the intensity of pest buildup. Species in natural communities occur at discrete points along the r-K continuum of reproductive maturity. Clearing forested land for agriculture, rotational burning practices, and replacing perennial grassland communities by cereal monocultures moves the agricultural community towards the r extreme. Plant breeders select for varieties which yield at an earlier age and lowerplant biomass, effectively moving a variety towards the r type. Features of more natural landscapes, such as hedgerows, may act as physical and biological adjuncts to agricultural production. They should exist as networks in agricultural lands to be most effective. Soil is of major importance in agroecosystems, and maintaining, deliberately, its vitality and resilience to agricultural perturbations is the very basis of sustainable land use.

The genus Castor comprises two species: the Eurasian beaver Castor fibre , and the North American beaver Castor canadensis . Both species suffered from overexploitation, but have seen a revival since the 1920s due to increased protection... more

The genus Castor comprises two species: the Eurasian beaver Castor fibre , and the North American beaver Castor canadensis . Both species suffered from overexploitation, but have seen a revival since the 1920s due to increased protection and reintroduction programmes. Increases in the populations and distributions of species that are able to modify ecosystems have generated much scientific interest. Here

Pseudomonas fluorescens SBW25 is a Gram-negative bacterium that grows in close association with plants. In common with a broad range of functionally similar bacteria it plays an important role in the turnover of organic matter and certain... more

Pseudomonas fluorescens SBW25 is a Gram-negative bacterium that grows in close association with plants. In common with a broad range of functionally similar bacteria it plays an important role in the turnover of organic matter and certain isolates can promote plant growth. Despite its environmental significance, the causes of its ecological success are poorly understood. Here we describe the development and application of a simple promoter trapping strategy (IVET) to identify P. fluorescens SBW25 genes showing elevated levels of expression in the sugar beet rhizosphere. A total of 25 rhizosphere-induced ( rhi ) fusions are reported with predicted roles in nutrient acquisition, stress responses, biosynthesis of phytohormones and antibiotics. One rhi fusion is to wss , an operon encoding an acetylated cellulose polymer. A mutant carrying a defective wss locus was competitively compromised (relative to the wild type) in the rhizosphere and in the phyllosphere, but not in bulk soil. The rhizosphere-induced wss locus therefore contributes to the ecological performance of SBW25 in the plant environment and supports our conjecture that genes inactive in the laboratory environment, but active in the wild, are likely to be determinants of fitness in natural environments.

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve... more

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems, where the optimisation works at two levels: a first optimisation, migration of agents which are distributed in a decentralised peer-to-peer network, operating continuously in time; this process feeds a second optimisation based on evolutionary computing that operates locally on single peers and is aimed at finding solutions to satisfy locally relevant constraints. The Digital Ecosystem was then measured experimentally through simulations, with measures originating from theoretical ecology, evaluating its likeness to biological ecosystems. This included its responsiveness to requests for applications from the user base, as a measure of the ecological succession (ecosystem maturity). Overall, we have advanced the understanding of Digital Ecosystems, creating Ecosystem-Oriented Architectures (EOA) where the word ecosystem is more than just a metaphor.

Background: Global commerce and human transportation are responsible for the range expansion of various insect pests such as the plant sucking aphids. High resolution DNA markers provide the opportunity to examine the genetic structure of... more

Background: Global commerce and human transportation are responsible for the range expansion of various insect pests such as the plant sucking aphids. High resolution DNA markers provide the opportunity to examine the genetic structure of aphid populations, identify aphid genotypes and infer their evolutionary history and routes of expansion which is of value in developing management strategies. One of the most widespread aphid species is the peach-potato aphid Myzus persicae, which is considered as a serious pest on various crops in many parts of the world. The present study examined the genetic variation of this aphid at a world scale and then related this to distribution patterns. In particular, 197 aphid parthenogenetic lineages from around the world were analysed with six microsatellite loci.

Marx called a social pattern "contradictory" if the conditions of its maintenance are also key ingredients for its demise. The science of ecology, too, studies patterns the conditions for whose maintenance are also key ingredients for... more

Marx called a social pattern "contradictory" if the conditions of its maintenance are also key ingredients for its demise. The science of ecology, too, studies patterns the conditions for whose maintenance are also key ingredients for their demise. The historical materialist notion of contradiction has a close counterpart in the ecological notion of succession. Succession is a process by which the structure of a biological community --both niche structure and species structure --changes as a result of each species' modification of the habitat. Just by living, each species member alters its environment, and in non-climax communities these effects, summed over all living things, constitute disequilibria. The habitat changes, and with it the niche structure. Gradually the species structure of the community changes. Each seral stage, with its distinctive species structure, requires for its maintenance the ongoing existence of living members of each species in the structure; yet this condition is the key ingredient for succession, for the demise of the seral stage.

We assessed earthworm species composition and abundance during secondary succession at the Smithsonian Environmental Research Center, Maryland, USA. Land use history is well known at this site. Adjacent forest stands of different ages and... more

We assessed earthworm species composition and abundance during secondary succession at the Smithsonian Environmental Research Center, Maryland, USA. Land use history is well known at this site. Adjacent forest stands of different ages and other vegetation patches were sampled in 1998e99 and in 2006. Out of the 12 species three (Eisenoides loennbergi, Bimastos palustris, Diplocardia caroliniana) were native, the rest were European peregrine earthworms. Native species were mainly found in mature forests, otherwise the species composition of mature and successional stands was similar. Earthworm density and biomass was significantly higher in the successional forests, than in the mature forests, and this pattern appears to be stable at a decadal time scale. Two smaller stands that have never been clearcut did not harbor any earthworms. The forest floor on these sites had a thick organic layer, moder humus and low pH. Bulk density was highest in the youngest (50e70 years) forests. It appears that as the forests enter to a late successional stage (150 years), they no longer can support high abundance of litter feeding earthworms.

Division of labour is a key factor in the ecological success of social insects. Groups of individuals specializing on a particular behaviour are known as castes and are usually distinguished by morphology or age. Physiology plays a key... more

Division of labour is a key factor in the ecological success of social insects. Groups of individuals specializing on a particular behaviour are known as castes and are usually distinguished by morphology or age. Physiology plays a key role in both these types of caste, in either the developmental physiology which determines morphology, or the temporal changes in physiology over an insects life. Physiological correlates of morphological or temporal caste include differences in gland structure, secretory products, leanness, neuroanatomy and neurochemistry. However, purely physiological castes could also occur. Physiological castes are discrete groups of same-age same-size individuals with particular physiological competencies, or groups of individuals with similar physiology crossing age or size groups. A stable physiological caste occurs in the monomorphic Pharaohs ant, where some ants can detect old pheromone trails and retain this specialization over time. These ants differ physiologically from other workers, and the differences arise before eclosion. More temporary physiological castes occur in the ant Ectatomma where brood care specialists have more developed ovarioles than other same-aged workers, and in the honeybee where nurses, wax-workers and soldiers all differ physiologically from same-aged nestmates. Physiology is an important aspect of caste, not only in its contribution to age-related and morphological castes, but also in its own right as a caste grouping factor. While age and morphological differences make caste structures accessible for study, more cryptic physiological castes may play just as important a role in division of labour.

Lessons learned from the study of ecological succession have much to offer contemporary environmental problem solving but these lessons are being underutilized. As anthropogenic disturbances increase, succession is more relevant than... more

Lessons learned from the study of ecological succession have much to offer contemporary environmental problem solving but these lessons are being underutilized. As anthropogenic disturbances increase, succession is more relevant than ever. In this review, we suggest that succession is particularly suitable to address concerns about biodiversity loss, climate change, invasive species, and ecological restoration. By incorporating modern experimental techniques and linking results across environmental gradients with meta-analyses, studies of succession can substantially improve our understanding of other ecological phenomena. Succession can help predict changes in biodiversity and ecosystem services impacted by invasive species and climate change and guide manipulative responses to these disruptions by informing restoration efforts. Succession is still a critical, integrative concept that is central to ecology.

Los estudios ecológicos demuestran que los sistemas agroforestales y los barbechos de la roza, tumba y quema sirven como hábitats para la vida silvestre, como corredores entre parches de bosque y como escudos contra los efectos de borde,... more

Los estudios ecológicos demuestran que los sistemas agroforestales y los barbechos de la roza, tumba y quema sirven como hábitats para la vida silvestre, como corredores entre parches de bosque y como escudos contra los efectos de borde, tales como temperaturas extremas, desecación e incendios. Además, los bosques se recuperan mucho más rápidamente después de la agricultura migratoria que tras la ganadería o los monocultivos de altos insumos. Sin embargo, los agricultores migratorios son percibidos como la amenaza principal contra la Reserva de la Biosfera Maya. En un afán por mejorar las condiciones de vida de los pequeños agricultores y a la vez proteger los bosques, algunos grupos conservacionistas están promoviendo prácticas que permitan a los agricultores producir más alimentos e ingresos con menos área cultivada.

Insects are major components of forest ecosystems, representing most of the biological diversity and affecting virtually all processes and uses. In the USA, bark beetles (Coleoptera: Curculionidae, Scolytinae) heavily influence the... more

Insects are major components of forest ecosystems, representing most of the biological diversity and affecting virtually all processes and uses. In the USA, bark beetles (Coleoptera: Curculionidae, Scolytinae) heavily influence the structure and function of these ecosystems by regulating certain aspects of primary production, nutrient cycling, ecological succession and the size, distribution and abundance of forest trees. The purpose of this report is to review tree and stand factors associated with bark beetle infestations and analyze the effectiveness of vegetation management practices for mitigating the negative impacts of bark beetles on forest ecosystems. We describe the current state of our knowledge and identify gaps for making informed decisions on proposed silvicultural treatments. This review draws from examination of 498 scientific publications (many of which are cited herein) on this and related topics. #

The effects of solid organic wastes from a marine fish farm on sediment was tested using macrobenthic fauna as biological indicators. Impact on benthic fauna was evaluated in the vicinity of a fish farm in the Tyrrhenian Sea (Western... more

The effects of solid organic wastes from a marine fish farm on sediment was tested using macrobenthic fauna as biological indicators. Impact on benthic fauna was evaluated in the vicinity of a fish farm in the Tyrrhenian Sea (Western Mediterranean) between July 2001 and October 2002. Changes in benthic community structure were investigated using multivariate, distributional and univariate analyses (diversity indices, AMBI and M-AMBI). The results showed sharp disturbance of assemblages under the cages and no effects in the area more than 25 m from the cages. Sediment alterations were related to an increase in farmed biomass and its wastes, as well as to low current speed that allowed accumulation of organic matter on the sea floor. It was possible to follow the ecological succession from slightly altered assemblages to heavily polluted ones in the very short period of a single fish fattening cycle (15 months).

The giant kelp Macrocystis is the world's largest benthic organism and most widely distributed kelp taxon, serving as the foundation for diverse and energy-rich habitats that are of great ecological and economical importance. Although the... more

The giant kelp Macrocystis is the world's largest benthic organism and most widely distributed kelp taxon, serving as the foundation for diverse and energy-rich habitats that are of great ecological and economical importance. Although the basic and applied literature on Macrocystis is extensive and multinational, studies of large Macrocystis forests in the northeastern Pacific have received the greatest attention. This review synthesises the existing Macrocystis literature into a more global perspective. During the last 20 yr, the primary literature has shifted from descriptive and experimental studies of local Macrocystis distribution, abundance and population and community structure (e.g., competition and herbivory) to comprehensive investigations of Macrocystis life history, dispersal, recruitment, physiology and broad-scale variability in population and community processes. Ample evidence now suggests that the genus is monospecific. Due to its highly variable physiology and life history, Macrocystis occupies a wide variety of environments (intertidal to 60+ m, boreal to warm temperate) and sporophytes take on a variety of morphological forms. Macrocystis sporophytes are highly responsive to environmental variability, resulting in differential population dynamics and effects of Macrocystis on its local environment. Within the large subtidal giant kelp forests of southern California, Macrocystis sporophytes live long, form extensive surface canopies that shade the substratum and dampen currents, and produce and retain copious amounts of reproductive propagules. The majority of subtidal Macrocystis populations worldwide, however, are small, narrow, fringing forests that are productive and modify environmental resources (e.g., light), yet are more dynamic than their large southern California counterparts with local recruitment probably resulting from remote propagule production. When intertidal, Macrocystis populations exhibit vegetative propagation. Growth of high-latitude Macrocystis sporophytes is seasonal, coincident with temporal variability in insolation, whereas growth at low latitudes tracks more episodic variability in nutrient delivery. Although Macrocystis habitat and energy provision varies with such ecotypic variability in morphology and productivity, the few available studies indicate that Macrocystis -associated communities are universally diverse and productive. Furthermore, temporal and spatial variability in the structure and dynamics of these systems appears to be driven by processes that regulate Macrocystis distribution, abundance and productivity, rather than the consumptive processes that make some other kelp systems vulnerable to overexploitation. This global synthesis suggests that the great plasticity in Macrocystis form and function is a key determinant of the great global ecological success of Macrocystis .

Background: Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is... more

Background: Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is available for organisms living at circumneutral pH. However, very little is known about how acidophilic bacteria, especially those used for industrial copper bioleaching, cope with environmental iron loads that can be 10 18 times the concentration found in pH neutral environments. This study was motivated by the need to fill this lacuna in knowledge. An understanding of how microorganisms thrive in acidic ecosystems with high iron loads requires a comprehensive investigation of the strategies to acquire iron and to coordinate this acquisition with utilization, storage and oxidation of iron through metal responsive regulation. In silico prediction of iron management genes and Fur regulation was carried out for three Acidithiobacilli: Acidithiobacillus ferrooxidans (iron and sulfur oxidizer) A. thiooxidans and A. caldus (sulfur oxidizers) that can live between pH 1 and pH 5 and for three strict iron oxidizers of the Leptospirillum genus that live at pH 1 or below.

Community succession is an important process in modulating the structure of benthic soft-bottom communities. A field experiment was conducted aiming (1) to describe the successional development in a subtidal soft-bottom community over a... more

Community succession is an important process in modulating the structure of benthic soft-bottom communities. A field experiment was conducted aiming (1) to describe the successional development in a subtidal soft-bottom community over a two-year period, (2) to estimate the time necessary for the developing community to resemble the surrounding natural community, and (3) to evaluate the effect of seasonal onset

In this study we report similar biotic response patterns in planktic foraminiferal assemblages, whether in association with volcanism, impacts or climate change at the end of the Cretaceous and early Tertiary. During and after each type... more

In this study we report similar biotic response patterns in planktic foraminiferal assemblages, whether in association with volcanism, impacts or climate change at the end of the Cretaceous and early Tertiary. During and after each type of catastrophe two groups dominate high stress assemblages: (1) the small Guembelitria species, which are interpreted as having thrived in eutrophic surface waters where other species rarely survived; and (2) the low oxygen tolerant small Heterohelix species, which thrived at times of an expanding oxygen minimum zone associated with high nutrients and a stratified water column.

Landslides are excellent illustrations of the dynamic interplay of disturbance and succession. Restoration is difficult on landslide surfaces because of the high degree of spatial and temporal heterogeneity in soil stability and... more

Landslides are excellent illustrations of the dynamic interplay of disturbance and succession. Restoration is difficult on landslide surfaces because of the high degree of spatial and temporal heterogeneity in soil stability and fertility. Principles derived from more than a century of study of ecological succession can guide efforts to reduce chronic surface soil erosion and restore both biodiversity and ecosystem function. Promotion of the recovery of self-sustaining communities on landslides is feasible by stabilization with native ground cover, applications of nutrient amendments, facilitation of dispersal to overcome establishment bottlenecks, emphasis on functionally redundant species and promotion of connectivity with the adjacent landscape. Arrested succession through resource dominance by a single species can be beneficial if that species also reduces persistent erosion, yet the tradeoff is often reduced biodiversity. Restoration efforts can be streamlined by using techniques that promote successional processes.

In the final analysis, sustainable agriculture must derive from applied ecology, especially the principle of the regulation of the abundance and distribution of species (and, secondarily, their activities) in space and time. Interspecific... more

In the final analysis, sustainable agriculture must derive from applied ecology, especially the principle of the regulation of the abundance and distribution of species (and, secondarily, their activities) in space and time. Interspecific competition in natural ecosystems has its counterparts in agriculture, designed to divert greater amounts of energy, nutrients, and water into crops. Whereas natural ecosystems select for a diversity of species in communities, recent agriculture has minimized diversity in favour of vulnerable monocultures. Such systems show intrinsically less stability and resilience to perturbations. Some kinds of crop rotation resemble ecological succession in that one crop prepares the land for successive crop production. Such rotations enhance soil organic processes such as decomposition and material cycling, build a nutrient capital to sustain later crop growth, and reduce the intensity of pest buildup. Species in natural communities occur at discrete points along the r-K continuum of reproductive maturity. Clearing forested land for agriculture, rotational burning practices, and replacing perennial grassland communities by cereal monocultures moves the agricultural community towards the r extreme. Plant breeders select for varieties which yield at an earlier age and lowerplant biomass, effectively moving a variety towards the r type. Features of more natural landscapes, such as hedgerows, may act as physical and biological adjuncts to agricultural production. They should exist as networks in agricultural lands to be most effective. Soil is of major importance in agroecosystems, and maintaining, deliberately, its vitality and resilience to agricultural perturbations is the very basis of sustainable land use.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired infections that are becoming increasingly difficult to combat because of emerging resistance to all current antibiotic classes. The evolutionary... more

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired infections that are becoming increasingly difficult to combat because of emerging resistance to all current antibiotic classes. The evolutionary origins of MRSA are poorly understood, no rational nomenclature exists, and there is no consensus on the number of major MRSA clones or the relatedness of clones described from different countries. We resolve all of these issues and provide a more thorough and precise analysis of the evolution of MRSA clones than has previously been possible. Using multilocus sequence typing and an algorithm, BURST, we analyzed an international collection of 912 MRSA and methicillinsusceptible S. aureus (MSSA) isolates. We identified 11 major MRSA clones within five groups of related genotypes. The putative ancestral genotype of each group and the most parsimonious patterns of descent of isolates from each ancestor were inferred by using BURST, which, together with analysis of the methicillin resistance genes, established the likely evolutionary origins of each major MRSA clone, the genotype of the original MRSA clone and its MSSA progenitor, and the extent of acquisition and horizontal movement of the methicillin resistance genes. Major MRSA clones have arisen repeatedly from successful epidemic MSSA strains, and isolates with decreased susceptibility to vancomycin, the antibiotic of last resort, are arising from some of these major MRSA clones, highlighting a depressing progression of increasing drug resistance within a small number of ecologically successful S. aureus genotypes.

Blooms of the disaster opportunist Guembelitria species are proxies for environmental catastrophes, whether impact or volcanism, leading to severe biotic stress crises that may range from temporary exclusion of ecological specialists and... more

Blooms of the disaster opportunist Guembelitria species are proxies for environmental catastrophes, whether impact or volcanism, leading to severe biotic stress crises that may range from temporary exclusion of ecological specialists and generalists to mass extinctions. During the late Maastrichtian and early Danian (zones P0 and Pla), Guembelitria blooms show global distributions, but with the largest blooms (40 -80% Guembelitria) in low and middle latitudes and only minor blooms (10 -20%) in high latitudes. Late Maastrichtian Guembelitria blooms are, so far, known from the Indian Ocean and eastern Tethys. The most intense Guembelitria blooms (>60% Guembelitria) occurred in shallow continental shelf areas, slope/shelf margins and volcanic provinces of the Indian Ocean. What these environments have in common is high nutrient influx (eutrophication) either from continental runoff, upwelling along continental margins or volcanic input. At times of biotic crises, Guembelitria blooms may have spread rapidly to the exclusion of most or all other species, much like today's red tides, but with near global distributions.

In northern Italy, on soil managed with three different tillage systems (conventional tillage, ridge tillage, and no-tillage) and submitted to standard cultural practices (crop rotation, and chemical weed control), the weed vegetation was... more

In northern Italy, on soil managed with three different tillage systems (conventional tillage, ridge tillage, and no-tillage) and submitted to standard cultural practices (crop rotation, and chemical weed control), the weed vegetation was assessed at the beginning of the trial (1987) and after six, and eight years. The aims were to evaluate (1) the effect of tillage systems on the weeds; and (2) the possibility of linking the floristic changes under reduced disturbance to the theory of ecological succession. The weeds were categorised according to life-forms (biological groups), periodicity types (ecophysiological groups), dispersal types and seed longevity. Data were analysed using Sørenson's Indices of Similarity, the Independence test, and Principal Components Analysis. The tillage systems profoundly altered the weed community: in undisturbed soils the importance of the geophyte and hemicryptophyte species, and among the annuals, Digitaria sanguinalis, Conyza canadensis and Kickxia elatine increased, as well as that of the wind-dispersed weeds. The species linked to disturbance were annuals and in particular Amaranthus spp., Chenopodium album and Echinochloa crus-galli. After eight years the floristic evolution in the reduced tillage system can be interpreted on the basis of ecological succession. The community that has formed assumes, from the quantitative point of view, characteristics of a pioneer community of secondary succession with a predominance of annual species and a large number of wind-dispersed plants. Qualitatively there is a movement towards a more mature community that could become similar to that of the woodland edge, with more perennial species, shrubs, and bird-dispersed plants. The implications of these conclusions are discussed in terms of weed management.

The option left by Art. 22 of the Regulation 650/2012 to the testator as to choosing the law applicable to the succession (lex hereditatis) strikes the balance between the law of the habitual residence and the law of nationality and has... more

The option left by Art. 22 of the Regulation 650/2012 to the testator as to choosing the law applicable to the succession (lex hereditatis) strikes the balance between the law of the habitual residence and the law of nationality and has to be assessed as a positive development. Interpretation issues arise out of the provisions related to the choice of the law applicable to the succession, in particular when the choice is made by a mutual or a joint will or regarding the substantive validity or the form of the choice. In principle, the choice of the national law as applicable to the succession has an impact on international jurisdiction as it leads to the dissociation of forum and jus, because the court of the last habitual residence of the deceased seized upon the basis of Art 4 shall apply the law of the nationality of the deceased. However the dissociation can be dissipated and the correlation (or coincidence) of forum and jus reestablished (Art. 5-7), provided that the law chosen...

The role of tropical forests in sustainable development mechanisms and payments for environmental services is becoming increasingly important. Therefore, there is a greater need for accurate and detailed information about their... more

The role of tropical forests in sustainable development mechanisms and payments for environmental services is becoming increasingly important. Therefore, there is a greater need for accurate and detailed information about their biophysical characteristics (e.g., Leaf area index -LAI) along different stages of ecological succession. Remote sensing offers the possibility of providing relatively accurate estimations of such biophysical characteristics at a reasonable cost for most regional projects. The objectives of this study are to (1) document the variability of LAI in different stages of secondary growth in a tropical moist forest, (2) estimate LAI from spectral vegetation indices (SVIs), and (3) link LAI to the estimation of other canopy physiognomic characteristics. We found that segregation of LAI measurements by successional stage (early, intermediate, late) contributed to a better definition of the relationship between LAI and the SVIs. In addition, we conclude that the propagation of errors of precision through the SVI formulas must be taken into consideration along with intra-site and radiometric variability when uncertainty terms are calculated. From a linear regression analysis, we found that there is only a minimal difference between the nonparametric Theil -Sen and classical least-squares regressions. We also found that not only does the Lorentzian cumulative transition function describe the relationship between LAI and the SVIs, it also provides an estimate of the range of LAI values to which each index is sensitive. D

This work was carried out at Viçosa (20 º45'S, 42 º07'W) in the Southeastern region of Minas Gerais. The study examed the changes occurred in the stand between surveys done in 1984 and 1998. Species were then classified as pioneers, early... more

This work was carried out at Viçosa (20 º45'S, 42 º07'W) in the Southeastern region of Minas Gerais. The study examed the changes occurred in the stand between surveys done in 1984 and 1998. Species were then classified as pioneers, early secondary and late secondary. Changes in diametric distribution and absolute density were also investigated. Means were compared through student's t and square-chi (c2) tests. The stand showed to be constituted of nine pioneers, 56 early secondary, and 29 late secondary. Except for Plinia glomerata Berg.) Amshoff and Sorocea bonplandii (Daill.) Burger. Lanjow & Boer, no increase in absolute density could be detected for the individuals from the group of early secondary. The same trend was observed with in the pioneer species, without exceptions. These findings point out a tendency for decreasing importance of these ecological groups. Protium warmingianum March., the only late secondary to be analyzed, showed a significant increase in its absolute density. Overall, these facts suggested an improvement in the conditions of the area for the support of more advanced ecological groups in the successional scale.

Fire is an important disturbance that can impact biodiversity and ecosystem functions. Although fire impacts have been well studied in plants and some animals, the effects of fire on litter-dwelling arthropods remain poorly documented. I... more

Fire is an important disturbance that can impact biodiversity and ecosystem functions. Although fire impacts have been well studied in plants and some animals, the effects of fire on litter-dwelling arthropods remain poorly documented. I investigated the effect of time-since-burn on litter-dwelling arthropods in a Florida scrub ecosystem. I measured total arthropod richness and diversity as well as arachnid detritivore and predator abundance along a time-since-burn chronosequence. Arthropod richness and diversity and arachnid abundance significantly increased within 8 years post-burn. Arthropod richness and diversity and arachnid abundance did not differ between 8 and 89 years since last burn. These results demonstrate that litter-dwelling arthropods can quickly re-establish their community composition within 8 years after a burn, which may have important consequences for litter decomposition and nutrient cycling rates over successional time.

Abstrak Pulau-pulau Krakatau memiliki dinamika secara geomorfologi, dan berbagai perubahan fisik yang berlangsung memberikan dampak terhadap biota, termasuk pada proses dan tingkat pergantian suksesi komunitasnya. Tujuan penelitian ini... more

Abstrak Pulau-pulau Krakatau memiliki dinamika secara geomorfologi, dan berbagai perubahan fisik yang berlangsung memberikan dampak terhadap biota, termasuk pada proses dan tingkat pergantian suksesi komunitasnya. Tujuan penelitian ini untuk menjelaskan kondisi terkini dan proses kolonisasi komunitas karang, termasuk status kerusakan komunitas karang dan disturbansi lingkungan yang mempengaruhinya. Line intercept transect dilakukan di enam stasiun pada dua kedalaman yang berbeda yakni 5 dan 10m. Sedangkan observasi terhadap komunitas koral dilakukan dengan perekaman video. Hasil penelitian ini menunjukkan bahwa suksesi atau perkembangan komunitas (i.e. kolonisasi) karang yang dijumpai di Pulau Anak Krakatau masih mengindikasikan tahap awal kolonisasi, berbeda dengan komunitas karang yang dijumpai di Pulau Rakata dan Panjang. Diversifikasi komunitas karang di kedua pulau tersebut, menunjukkan dominansi spesies oportunis dan pioner (i.e. Pocillopora dan Seriatopora) yang umum dijumpai di Anak Krakatau sudah tergantikan. Dominansi dari beberapa spesies karang telah mengindikasikan terjadinya proses eksklusi kompetitif di antara komunitas karang. Tiga tipe komunitas karang yang dijumpai dapat dibedakan menurut karakteristik masing-masing kawasan, yaitu komunitas kawasan terpapar, semi terpapar/terlindung, dan terlindung. Kerusakan komunitas karang di Krakatau berdasarkan kriteria indeks kerusakan karang (CDI) sudah termasuk kedalam kategori wilayah "hot spot", dimana sangat memerlukan perhatian, pengawasan, pengamatan atau restorasi komunitas karang. Hasil dari penelitian ini memberikan gambaran bahwa terjadinya kolonisasi dan tingkat kerusakan komunitas karang perlu menjadi acuan dalam pengelolaan kawasan terumbu karang di Cagar Alam Laut Krakatau.

Insects are major components of forest ecosystems, representing most of the biological diversity and affecting virtually all processes and uses. In the USA, bark beetles (Coleoptera: Curculionidae, Scolytinae) heavily influence the... more

Insects are major components of forest ecosystems, representing most of the biological diversity and affecting virtually all processes and uses. In the USA, bark beetles (Coleoptera: Curculionidae, Scolytinae) heavily influence the structure and function of these ecosystems by regulating certain aspects of primary production, nutrient cycling, ecological succession and the size, distribution and abundance of forest trees. The purpose of

Fossil beetles from two last interglacial lake deposits from southern Wairarapa, central New Zealand are provisionally ascribed to marine oxygen isotope stages (MIS) 5a–e. Both assemblages represent ecological successions from lake... more

Fossil beetles from two last interglacial lake deposits from southern Wairarapa, central New Zealand are provisionally ascribed to marine oxygen isotope stages (MIS) 5a–e. Both assemblages represent ecological successions from lake margins to forest. The lower sample (MIS 5e) is characterized by species found today in northern New Zealand. These species, including Lorelus crassicornis, ‘Dasytes’ laticeps, Cryptobius nitidius, ‘Stenomalium’ sulcithorax, Psilocnaeia nana, and Microbrontes lineatus, represent a southward displacement from modern distributions by up to 700 km. Climate reconstruction indicates that temperatures at the time of deposition were 1.6–2.5°C warmer in the summer (January) and 2.3–3.2°C warmer in the winter (July) than at present. These results match local and regional pollen and phytolith findings of warmer, wetter conditions at the thermal maximum of the last interglaciation. In contrast, the upper sample is characterized by species that have widespread modern...