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

An impressive fit to historical data suggests to biologists
that a given ecological model is highly valid.
Models often achieve this fit at the expense of exaggerated
complexity that is not justified by empirical evidence.
Because overfitted theories complement the
traditional assumption that ecology is ‘messy’, they
generally remain unquestioned. Using predation theory
as an example, we suggest that a fit-driven appraisal of
model value is commonly misdirected; although fit to
historical data can be important, the simplicity and generality
of a theory – and thus its ecological value – are
of comparable importance. In particular, we argue that
theories whose complexity greatly exceeds the complexity
of the problem that they address should be
rejected. We suggest heuristics for distinguishing
between valuable ecological theories and their overfitted
brethren.

- by Christopher X Jon Jensen
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- Ecological Modeling, Ecological Modelling

Despite the rapid urban transformation in green space in most cities in Ghana, knowledge on urban tree diversity and the evidence of the consequences of built-up expansion on trees is scanty. This article provides a novel contribution to the current urban trees abundance and richness in Kumasi Metropolitan Area, Ghana. Post classification change detection technique was applied to quantify urban land use land cover (LULC) transformations (urban forest, agricultural, riparian vegetation and built-up) from 2007 to 2017. Species rank abundance distribution and richness were quantified using geometric series and individual-based rarefaction models. A total of 858 individual trees belonging to 76 taxa were recorded across the four LULC classes. Species abundance distributions in three LULC types varied substantially, with the exception of riparian LULC (slope [k] ¼ 0.086 6 0.12, v 2 P ¼ 19.42, P ¼ 0.15). Land use pressure led to a 13.56 km 2 reduction in forest cover, while built-up and agricultural LULC increased by 31.13 and 1.85 km 2 , respectively. These disturbances did not only affect indigenous tree dominance (41.3%) in favour of exotic species (58.7%) in the agricultural and built-up LULC types but also impacted on tree abundance (n ¼ 126) and richness (n ¼ 28) in agricultural land compared to abundance (n ¼ 280) and richness (n ¼ 67.86) in forest cover. Despite the contribution of LULC transformation to increase in tree diversity, there is the likelihood of future dominance of exotic species in the Metropolis if urban planners do not institute measures to conserve indigenous species.

- by Dr. Collins Ayine Nsor
- •
- Biostatistics, Ecological Modeling, Vegetation Ecology, Fish Ecology

"Home range behaviour is a common pattern of space use, having fundamental consequences for ecological processes. However, a general mechanistic explanation is still lacking. Research is split into three separate areas of inquiry – movement models based on random walks, individual-based models based on optimal foraging theory, and a statistical modelling approach – which have developed without much productive contact. Here we review recent advances in modelling home range behaviour, focusing particularly on the problem of identifying mechanisms that lead to the emergence of stable home ranges from unbounded movement paths. We discuss the issue of spatiotemporal scale, which is rarely considered in modelling studies, as well as highlighting the need to consider more closely the dynamical nature of home ranges. Recent methodological and theoretical advances may soon lead to a unified approach, however, conceptually unifying our understanding of linkages among home range
behaviour and ecological or evolutionary processes."

- by Luca Borger (Börger) and +1
- •
- Statistics, Animal Behavior, Movement Ecology, Modeling

Current developments in ecosystem theory to understand ecological complexity, particularly those incorporating and applying thermodynamic principles, are making it possible to integrate various ecosystem approaches into a consistent theoretical framework. The time, therefore, seems right to apply this theory to explain observations published in the ecological literature that typically lack linkages to ecological theory or other rule-based explanations. This paper presents the foundations of that theory of ecological complexity in eight observational principles and summarizes the results from a review of a number of papers using thermodynamic principles to explain ecological observations. The theory will continue to evolve and be modified as more test cases are made, however, here explanations of some published ecological observations are presented to illustrate how the ecosystem theory is applied. #

- by brian fath
- •
- Thermodynamics, Ecological Modeling, Ecology, Ecosystem Approach

This study reviews fisheries and management practices and provides estimates of the present and potential fish yield of Ethiopian inland fisheries. Published and unpublished sources were used, 28 years of fisheries data were analyzed and empirical models were applied to estimate potential yield. Ethiopian waters hold about 180 fish species, some freshwater shrimps and crabs, commercially important microalgae and a diverse vegetation, all together of great economic and socio-cultural values. Fisheries provide economic support directly and indirectly to about half a million people and serve as source of affordable protein for many households. Our estimate of potential yield (94,500 t yr_1 ± 5.2% distributed as 73,100 t yr_1 ±3.3% for lentic and about 21,400 t yr_1 ± 11.9% for lotic ecosystems) is far above the current yield levels, suggesting substantial scope for fisheries expansion. Nevertheless, some lakes already show signs of overfishing of target species, while others appear to have growing or stable fisheries. As yet, no ornamental fishery occurs in the country and the potential of indigenous fish species for ornamental fish trade needs to be evaluated. Management follows the traditional command and control approach and it seems that there is a general lack of awareness and scientific information on the fisheries. Major challenges of the fisheries are high post-harvest loss, lack of stringent sanitary and phytosanitary standards for assuring good quality products, and overfishing of valuable fish species in some lakes. Thus, continuous fisheries monitoring and yield assessment are urgently needed as is research directed toward unexploited water bodies and species.

- by Gashaw Tesfaye
- •
- Aquatic Ecology, Fisheries, Ecological Modeling, Natural Resource Management
- by Dan Mellamphy and +1
- •
- Ecological Engineering, Geology, Geomorphology, Ontology
- by Konstantinos Tsagarakis
- •
- Ecological Modeling, Ecopath, Mediterranean Sea

The following points, which represent a path to a semiotics of being, are pertinent to various sub-fields at the conjunction of semiotics of nature (biosemiotics, ecosemiotics, zoosemiotics) and semiotics of culture—semioethics and existential semiotics included. 1) Semiotics of being entails inquiry at all levels of biological organization, albeit, wherever there are individuals, with emphasis on the living qua individuals (integrated biological individualism). 2) An Umwelt is the public aspect (cf. the Innenwelt, the private aspect) of a phenomenal/experienced world that is organism-specific (rather than species-specific) and ultimately refers to an existential realm. 3) Existential universals at work on Earth include seeking out the edible, dwelling in a medium, holding a phenomenal world (possibly an Umwelt) and being endowed with life, and consequently being mortal. 4) Human Umwelten include speechless Umwelten, spoken Umwelten and alphabetic Umwelten. 5) An Uexküllian phenomenology—stating that semiotic states represent the general class to which all mental/cognitive states belong—can draw on the works of the phenomenologists David Abram and Ted Toadvine (The notion of semiotic states is treated in Tønnessen 2009a: 62–63. For an introduction to eco-phenomenology, see Brown and Toadvine (eds.) 2003). 6) A task for such a phenomenology is to portray the natural history of the phenomenal world. 7) An imperative task in our contemporary world of faltering biological diversity is that of Umwelt mapping, i.e. a mapping of ontological niches. 8) The ecological crisis is an ontological crisis with historical roots in humankind’s domestication of animals and plants, which can be taken as archetypical for our attempted planet-scale taming of the wild. 9) The process of globalization is expressed by correlated trends of depletion of semiotic diversity and semiotic diversification. 10) Semiotic economy is a field which task it is to map the human ontological niche insofar as its semiotic relations are of an economic nature. All ten points will be commented (explicitly or implicitly) in due time.

- by Morten Tønnessen
- •
- Semiotics, Cultural Semiotics, Phenomenology, Ecological Modeling

Social inclusion is an important goal for people with intellectual and developmental disabilities, families, service providers, and policymakers; however, the concept of social inclusion remains unclear, largely due to multiple and conflicting definitions in research and policy. We define social inclusion as the interaction between two major life domains: interpersonal relationships and community participation. We then propose an ecological model of social inclusion that includes individual, interpersonal, organizational, community, and socio-political factors. We identify four areas of research that our ecological model of social inclusion can move forward: (1) organizational implementation of social inclusion; (2) social inclusion of people with intellectual and developmental disabilities living with their families, (3) social inclusion of people along a broader spectrum of disability, and (4) the potential role of self-advocacy organizations in promoting social inclusion.

Essay published in Seminar, 2015. Is the Anthropocene a truly global concept, or is it a new form of extending Eurocentric histories? In this essay I consider the science of the Anthropocene from a methodological perspective, considering how preoccupations with specific time frames structures analysis. Like history, parts of the science of global change need to be 'provincialized.' (CLICK ON LINK, OPEN-ACCESS JOURNAL)

The Reynolds transport theorem (RTT) from mathematics and engineering has a rich history of success in mass transport dynamics and traditional thermodynamics. This paper introduces RTT as a complementary approach to traditional compartmental methods used in ecological modeling and network analysis. A universal system equation for a generic flow quantity is developed into a generic open-system differential expression for conservation of energy. Nonadiabatic systems are defined and incorporated into control volume (CV) and control surface (CS) perspectives of RTT where reductive assumptions in empirical data are then formally introduced, reviewed, and appropriately implemented. Compartment models are abstract, time-dependent systems of simultaneous differential equations describing storage and flow of conservative quantities between interconnected entities (the compartments). As such, they represent a set of flexible and somewhat informal, assumptions, definitions, algebraic manipulations, and graphical depictions subject to influence and selectively parsed expression by the modeler. In comparison, RTT compartment models are more rigorous and formal integro-differential equations and graphics initiated by the RTT universal system equation, forcing an ordered identification of simplifying assumptions, ending with clearly identified depictions of the transfer and transport of conservative substances in physical space and time. They are less abstract in the rigor of their equation development leaving less ambiguity to modeler discretion. They achieve greater consistency with other RTT compartment style models while possibly generating greater conformity with physical reality. Characteristics of the RTT approach are compared with those of a traditional compartment model of energy flow in an intertidal oyster-reef community. (J.R. Schramski). stocks, that is, transient storages of conserved substances, have little inherent formalism beyond a mathematical description of their rates of change by ordinary differential or difference equations. Ultimately, the combined pictorial, descriptive, and mathematical relations (e.g., assumptions, boundaries) remain abstractions heavily influenced by the modeler. Yet clear and consistent equation development, understanding, and interpretation are fundamental to the advancement and interpretation of widely disparate ecological network analyses (e.g., Gattie et al., 2006a,b;. To increase the rigor and consistency of compartment modeling, we introduce a formalism cultivated in engineering to describe and quantify mass transport and thermodynamic processes. The Reynolds transport theorem (Reynolds, 1903), through its development of an Eulerian control volume (CV) perspective, is a mature approach that formalizes flow and storage regimes and their corresponding equation development, explicitly ties pictorial representations to the mathematical representations, and ultimately opens ecological compartment modeling to the wider field of transport 0304-3800/$ -see front matter

- by Nadia N Kellam
- •
- Thermodynamics, Modeling, Ecological Modeling, Network Analysis

Coral reef fish spend their first few weeks developing in the open ocean, where eggs and larvae appear merciless to tides and currents, before attempting to leave the pelagic zone and settle on a suitable reef. This pelagic dispersal phase is the process that determines population connectivity and allows replenishment of harvested populations across multiple coral reef habitats. Until recently this pelagic larval dispersal phase has been poorly understood and has often been referred to as the ‘black-box’ in the life-history of coral reef fishes. In this perspective article we highlight three areas where mathematical and computational approaches have been used to aid our understanding of this important ecological process. We discuss models that provide insights into the evolution of the pelagic larval phase in coral reef fish, an unresolved question which lends itself well to a modelling approach due to the difficulty in obtaining empirical data on this life history strategy. We describe how studies of fish hearing and physical sound propagation models can be used to predict the detection distance of reefs for settling larval fish, and the potential impact of anthropogenic noise. We explain how random walk models can be used to explore individual- and group-level behaviour in larval fish during the dispersal and settlement stage of their life-history. Finally, we discuss the mutual benefits that mathematical and computational approaches have brought to and gained from the field of larval behaviour and dispersal of reef fishes.

“There was a time when natural resources seemed inexhaustible. We no longer have the luxury of this out-dated way of thinking. That is why in 2009 we incorporated a goal in our National Plan for Good Living to maintain our Ecological Footprint at a level within what our ecosystems can renew. Making decisions that affect Ecuador’s long-term sustainability requires utilizing science-based tools like Global Footprint Network accounting. We know that safeguarding our natural heritage and biodiversity means safeguarding the security of our citizens and our planet.”

Landscape configuration and dispersal characteristics are major determinants of population distribution and persistence in fragmented habitat. An individual-based spatially explicit population model was developed to investigate these factors using the distribution of nuthatches in an area of eastern England as an example. The effects of immigration and increasing the area of breeding quality habitat were explored. Predictions were compared with observed population sizes in the study area. Our model combined a nuthatch population simulator based on individual behaviour with a grid-based representation of the landscape; nuthatch life cycle and immigration parameters were user selectable. A novel aspect of the model is user-selection of habitat perceptual range. Using a realistic set of parameters, the number of breeding pairs predicted by the model matched observed numbers. According to model simulations, the main cause of nuthatch scarcity in the study area was the inability of patches to support viable populations without immigration from elsewhere. Modelled habitat management, which increased breeding quality habitat in existing woods, lowered the threshold above which the study area population became self-sustaining. The existence of a large core habitat area was critical in producing a self-sustaining population in this landscape, the same area in dispersed small woods failed to sustain populations.

- by Duncan McCollin and +1
- •
- Landscape Ecology, Ecological Modeling, Ecology, Dispersal Ecology

In this paper I will sketch an Umwelt ethics, i.e., an ethics that rests heavily on fundamental features of Jakob von Uexküll’s Umwelt theory. In the course of an interpretation of the Umwelt theory, a number of concepts are introduced. These include ontological niche, common-Umwelt, total Umwelt and bio-ontological monad. I then present an Uexküllian reading of the deep ecology platform. It is suggested that loss of biodiversity, considered as a physio-phenomenal entity, is the most crucial aspect of the ecological crisis, which can be understood as an ontological crisis.

- by Morten Tønnessen
- •
- Ethics, Ecological Modeling, Environmental Ethics, Biosemiotics

Using GIS and remote sensing tools, the current dissertation shows the impact of agricultural mutation in drylands and highlights the effect of date palm (Phoenix dactylifera) plantations (DPP) on desertification phenomenon in oases of the Algerian Sahara Desert. The spatiotemporal survey was conducted using three Landsat satellite images (TM-1984, ETM+-1999, and OLI-2013). Likelihood supervised classification was used to quantify DPP change over three decades, whereas four remote sensed indices were extracted as indicators of desertification process in the study area: Normalized Difference Vegetation Index (NDVI), Normalized Difference Moisture Index (NDMI), Salinity Index (SI-T), and Crust Index (CI). Generalized linear mixed models (GLMMs) were applied to test the effects of year and DPP ‘presence/absence’ for NDVI; year, DPP and NDVI for both CI and NDMI; year, DPP, NDVI and NDMI for SI-T. DPP area and tree numbers quadrupled over the last three decades with a surface increase of 4822 ha and more than 0.5 million trees. DPP presence positively influenced NDVI, NDMI and CI, but negatively affected SI-T. Highly significant positive relationships were found between NDVI—DPP, NDVI—NDMI, and NDVI—CI, although negative relationships were obtained between SI-T—NDVI and SI-T—NDMI. DPP areas indicated higher NDVI, NDMI and CI values, but with lower SI-T values compared to the rest of the desert habitats. Our results highlighted the potential role of DPP in controlling and mitigating desertification in hot drylands. This arises from the effectiveness of strategic agricultural policy programs. Landsat series data provided a cost-efficient tool for monitoring change in oases and arid environments.

- by Nacer TARAI and +1
- •
- Landscape Ecology, Remote Sensing, Plant Ecology, Organic agriculture

Mountain vegetation is strongly affected by temperature and is expected to shift upwards with climate change. Dynamic vegetation models are often used to assess the impact of climate on vegetation and model output can be compared with paleobotanical data as a reality check. Recent paleoecological studies have revealed regional variation in the upward shift of timberlines in the Northern and Central European Alps in response to rapid warming at the Younger Dryas/Preboreal transition ca. 11 700 years ago, probably caused by a climatic gradient across the Alps. This contrasts with previous studies that successfully simulated the early Holocene afforestation in the (warmer) Central Alps with a chironomid-inferred temperature reconstruction from the (colder) Northern Alps. We use LandClim, a dynamic landscape vegetation model to simulate mountain forests under different temperature, soil and precipitation scenarios around Iffigsee (2065 m a.s.l.) a lake in the Northwestern Swiss Alps, and compare the model output with the paleobotanical records. The model clearly overestimates the upward shift of timberline in a climate scenario that applies chironomid-inferred July-temperature anomalies to all months. However, forest establishment at 9800 cal. BP at Iffigsee is successfully simulated with lower moisture availability and monthly temperatures corrected for stronger seasonality during the early Holocene. The model-data comparison reveals a contraction in the realized niche of Abies alba due to the prominent role of anthropogenic disturbance after ca. 5000 cal. BP, which has important implications for species distribution models (SDMs) that rely on equilibrium with climate and niche stability. Under future climate projections, LandClim indicates a rapid upward shift of mountain vegetation belts by ca. 500 m and treeline positions of ca. 2500 m a.s.l. by the end of this century. Resulting biodiversity losses in the alpine vegetation belt might be mitigated with low-impact pastoralism to preserve species-rich alpine meadows.

- by Paul Henne
- •
- Ecological Modeling, Paleoecology, Palynology, Palaeoecology
- by Chandanathil Geevan and +2
- •
- Pastoralism (Social Anthropology), Ecological Modeling, Arid Land Ecology, Arid Zone

We describe conceptual and simulation models of land use within the intertidal zone of the Guayas River estuary to quantify the contribution of mangrove wetlands to maintaining environmental quality of a tropical estuary. The goal of this exercise is to demonstrate the important consideration of ecological constraints in determining economic and management decisions; and how modeling can be used to quantify impacts of land use such as loss of mangrove wetlands on environmental quality. Our conceptual model treats solar energy, river flow, and tides as forcing functions that control the properties of estuarine ecosystems, but also describes market forces and cultural policies as constraints on properties of socioeconomic systems. The controversy of coastal resource management in Ecuador centers around the relative impacts of shrimp pond construction and management as negative feedbacks to the environmental quality of the Guayas River estuary. Unique oceanographic processes and land use changes contribute to complex issues of water and habitat quality in this tropical estuary, the largest estuarine complex on the Pacific coast of South America. A dynamic box model was developed for the estuary and calibrated with data collected from a 14 month survey of water quality parameters throughout the estuary. Scenarios included conversion of mangroves to shrimp ponds in three regions of the estuary, and the construction of a dam by varying three different rates of river discharge at 100, 50 and 10% of 1989 base flow. Good water quality is maintained by the low residence time of water in the estuary (11 d) because of seasonally high river flow and tidal exchange. With a 90% reduction of mangrove forests in the estuary caused by shrimp pond construction, total nitrogen concentrations increased 5 fold. However, as river discharge decreased to 10%, the same construction caused a 60 fold increase in nitrogen concentrations to 250 μM. Increases in nitrogen concentrations were higher in the upper estuary region, with much less change in the lower estuary. Thus the sensitivity of environmental quality to changes in land use in the intertidal and upland zone are linked to the hydrography of the estuary and is site specific. In the future, the combinations of these ecological models together with economic analyses of the goods and services of mangroves may provide better techniques to evaluate the economic impacts of specific coastal zone management decisions.

- by Mariano Montaño
- •
- Cultural Policy, Science Policy, Ecological Economics, Water quality

Sloth bears (Melursus ursinus) are endemic to the Indian subcontinent. As a result of
continued habitat loss and degradation over the past century, sloth bear populations have
been in steady decline and now exist only in isolated or fragmented habitat across the entire
range. So, the conservation program should be provided to overcome the extinction of the
species of interest. In Similipal by using the Maximum Entropy model we develop a
distribution pattern with reference to presence only data. It was found that 10% of Similipal
are suitable for sloth bear habitat. The Sloth bear is very intensively distributed in the south
western part of similipal biosphere reserve. The northern and eastern part has a non
habitable climate for the sloth bear and also found to be tigers core habitat region. Some
what the core region provides some suitable habitat for the bears. Various environmental
variables may be contributing for this spatial distribution of Sloth bear. We also get that the
environmental variable that is the Bio 2, the mean diurnal temperature range has great
effect on the distribution pattern of sloth bear whereas the Bio 3, Isothermality has less
effect on the distribution pattern.

Ecological indices are used to provide summary information about a particular aspect of ecosystem behavior. Many such indices have been proposed and here we investigate two: exergy and Fisher Information. Exergy, a thermodynamically based index, is a measure of the maximum amount of useable work that can be extracted when a system is brought into equilibrium with a reference state. The measure for exergy used herein, also includes a factor to weigh the "complexity" of the ecological species. Fisher Information is an old statistical measure that has recently been applied as a way to detect change in system regime and as a measure of system order. These two indices are compared on a 10-compartment food web model undergoing five different perturbation scenarios. This food web model, although simple, allows for some interesting insight into the two indices. The results show that generally, although not always, exergy and Fisher Information respond differently, such that when one increases due to a perturbation the other decreases and vice versa. We provide a discussion as to the usefulness of these metrics as ecological indices and as their potential use as ecological goal functions in light of these findings.

- by brian fath
- •
- Thermodynamics, Ecological Modeling, Multidisciplinary, Ecological Modelling

High quality information on forest resources is important to forest ecosystem management. Traditional ground measurements are labor and resource intensive and at the same time expensive and time consuming. For most of the Slovenian forests, there is extensive ground-based information on forest properties of selected sample locations. However there is no continuous information of objectively measured vegetation height and canopy cover at appropriate resolution.
Currently, Light Detection And Ranging (LiDAR) technology provides detailed measurements of different forest properties because of its immediate generation of 3D data, its accuracy and acquisition flexibility. However, existing LiDAR sensors have limited spatial coverage and relatively high cost of acquisition. Satellite data, on the other hand, are low-cost and offer broader spatial coverage of generalized forest structure, but are not expected to provide accurate information about vegetation height.
Integration of LiDAR and satellite data promises to improve the measurement, mapping, and monitoring of forest properties. The primary objective of this study is to model the vegetation height and canopy cover in Slovenia by integrating LiDAR data, Landsat satellite data, and the use of machine learning techniques. This kind of integration uses the accuracy and precision of LiDAR data and the wide coverage of satellite data in order to generate cost-effective realistic estimates of the vegetation height and canopy cover, and consequently generate continuous forest vegetation map products to be used in forest management and monitoring.
Several machine learning techniques are applied to this task: they are evaluated and their performance is compared by using statistical significance tests. Ensemble methods perform significantly better than single- and multi-target regression trees and are further used for the generation of forest maps. Such maps are used for land-cover and land-use classification, as well as for monitoring and managing ongoing forest processes (like spontaneous afforestation, forest reduction and forest fires) that affect the stability of forest ecosystems.

- by Panče Panov
- •
- Machine Learning, Ecological Informatics, Ecological Modeling
- by Panče Panov
- •
- Remote Sensing, Ecological Informatics, Ecological Modeling

A paradigm for optimal state-space reconstruction with nonuniform time delays is proposed. A comparison based on a diffeomorphic measure and a smoothness cost function shows that the proposed methodology achieves a better reconstruction compared to a reconstruction based on time delays that are multiples of the first minimum of mutual information. It is also shown how the proposed methodology is a more reliable approach to determining the embedding dimension.

- by Chetan Nichkawde
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- Neuroscience, Collective Behavior, Social Theory, Cognitive Science

Effective management of introduced species requires the early identification of species that pose a significant threat of becoming invasive. To better understand the invasive ecology of species in New England, USA, we compiled a character data set with which to compare non-native species that are known invaders to non-native species that are not currently known to be invasive. In contrast to previous biological trait-based models, we employed a Bayesian hierarchical analysis to identify sets of plant traits associated with invasiveness for each of three growth forms (vines, shrubs, and trees). The resulting models identify a suite of ‘invasive traits’ highlighting the ecology associated with invasiveness for each of three growth forms. The most effective predictors of invasiveness that emerged from our model were ‘invasive elsewhere’, ‘fast growth rate’, ‘native latitudinal range’, and ‘growth form’. The contrast among growth forms was pronounced. For example, ‘wind dispersal’ was positively correlated with invasiveness in trees, but negatively correlated in shrubs and vines. The predictive model was able to correctly classify invasive plants 67% of the time (22/33), and non-invasive plants 95% of the time (204/215). A number of potential future invasive species in New England that deserve management consideration were identified.

- by Chris Martine
- •
- Statistics, Horticulture, Plant Ecology, Bayesian

The Asian hornet, Vespa velutina, has invaded Europe during the last few years. This hornet is a dangerous pest to honey bee colonies and can cause significant economic damages. In this study, current and future distributions of this pest in Europe and North Africa were analyzed using maximum entropy algorithm. Different environmental factors were used in the Maxent model to predict the suitability of the study area for this pest. Two future models with two Shared Socio-economic Pathways (126 and 585) were used to estimate the future distribution of V. velutina in 2050. The Maxent model for V. velutina showed high performance based on the analysis of omission/commission rates and the area under curve. Jackknife test showed the high importance of temperature variables in V. velutina distribution. The model maps indicated the potential invasion of this pest to other areas in Europe and North Africa including deserts in Libya and Egypt. Negative consequences of such invasion on beekeeping and environmental balance are expected.

- by Dr. Hossam Abou-Shaara
- •
- Ecological Modeling, Modeling and Simulation, Honey Bees, Hornets

The sea surface temperature (SST) in loggerhead turtle breeding areas affects the species reproductive biology. Less is known about the effects of changes in SST in the species foraging grounds. We used nesting data for the Mediterranean loggerhead turtle population breeding on the Greek island of Zakynthos to study the effect of SST in the population foraging grounds upon the initiation of nesting and the number of clutches laid. We found that the climatic conditions (SST) in the foraging grounds affected the population nesting phenology in the short term (i.e. within the same year); warmer years triggered an earlier onset of nesting. However, the effect of foraging grounds SST upon nesting is comparatively less important than the local conditions at the nesting ground. Although nesting phenology seems to depend on current's year foraging grounds SST the number of nests in our study rookery were negatively correlated with SSTs recorded 2 years prior nesting, with higher SST leading to fewer nests. From this point of view, climate change at the foraging grounds may influence the reproductive phenology of loggerheads.

- by Joseph Tzanopoulos
- •
- Climate Change, Reproduction, Modeling, Ecological Modeling

The removal, alteration and fragmentation of habitat in many parts of the world has led to a loss of biodiversity. Within the prevailing societal limitations the process is not easily reversed. Attempts are being made to minimise the fragmentation of remaining habitat by strategically reversing or managing habitat loss. Although their relative usefulness is a topic of debate among ecologists, habitat corridors are seen as one way of maintaining spatially dependent ecological processes within landscapes where habitat has been seriously depleted. Corridors can only be effective if they significantly contribute to the species sustaining processes of gene flow, resource access or the colonisation of vacant patches. We present a spatial habitat modelling methodology for evaluating the contribution and potential contribution of connecting paths to landscape connectivity. We have developed the spatial links tool (SLT), which maps link value across a region. The SLT combines connectivity measures from metapopulation ecology with the least cost path algorithm from graph theory, and can be applied to continuously variable landscape data. Combined with expert judgement, link value maps can be used to delineate habitat corridors. The approach capitalises on some synergies between ecological relevance and computational efficiency to produce an easily applied heuristic tool that has been successfully applied in NSW Australia.

- by Michael Drielsma
- •
- Ecological Modeling

In a recent paper ), we published a statistical model for predicting invasiveness of exotic woody plant species in New England. A dataset was compiled of 28 biological/ecological characters for each of 248 exotic trees, shrubs, and lianas currently available in the nursery trade in northeastern North America. We applied a Bayesian hierarchical analysis to explore 1) what set of plant traits confer invasive success on non-native plants in New England, and 2) which currently non-invasive species share important traits with the 33 woody species listed by the Invasive Plant Atlas of New England . Using this approach we were able to compare non-native species that are known invaders to non-native species that are not currently considered invasive in New England. One benefit of the hierarchical approach is that we could measure the responses of distinct growth forms, a crucial advantage not only for more robust predictions, but also for determining whether different invasion strategies are employed by each woody growth form (tree, shrub, liana).

- by Chris Martine
- •
- Botany, Plant Ecology, Climate Change, Climate Change Adaptation

Seascape ecology studies indicate that the spatial arrangement of habitat types and the topographic complexity of the seascape are major environmental drivers of fish distributions and diversity across coral reef ecosystems. Impairment of one component of an ecologically functional habitat mosaic and reduction in the architectural complexity of coral reefs is likely to lower the quality of habitat for many fish including important fished species. Documented declines in coral cover and topographic complexity are reported from a ...

- by Bryan Costa and +1
- •
- Climate Change, Ecological Modeling, Complexity, Seascape Ecology

A trophic structure model of the rocky coastal ecosystem in Bahia Tortugas, Mexico was constructed using Ecopath software to represent the main biomass flows in the system. Data for the model came from field observations (biomass estimates, stomach contents, and ecological observations for sea snails, abalones, lobster, some demersal finfishes, and macroalgae) carried out through ten field trips from 2006 to 2008. The results provide a snapshot of how the ecosystem operates. The model considers 23 functional groups. The total system throughput was 553 t/km2/year, 57% corresponds to internal consumption, 28% to respiration, 14% becomes detritus, and only 1% is removed through commercial fishing. The model suggests that even for exploited populations, predation and competition are heavier stresses than current fishing effort; however, because spiny lobster showed the second highest keystoneness’ index value, increasing fishing pressure on this group could strongly impact the entire ecosystem. We believe that this model has the potential to support management by allowing the exploration of the potential impacts of different fishing decisions at ecosystem level.

- by Salvador E . Lluch-Cota and +2
- •
- Marine Ecology, Ecological Modeling, Ecopath, Rocky Shores

Several models for marine biogeochemistry have been developed over the last decades. One of the most complex models currently available, the European Regional Seas Ecosystem Model (ERSEM), has been pointed out as the reference in terms of modeled processes, complexity and modeling philosophy. Its representation of marine trophic interactions and biogeochemical cycles has been widely accepted and recurrently visited and improved. Here we present a set of equations of a marine biogeochemical deterministic model that uses ERSEM as reference. The model is process-oriented and aims to be used in numerical simulations of different types ofmarine systems. Our formulation is based on the Living Functional Group (LFG) concept (Baretta and Ruardij, 1987; Vichi et al., 2007), but instead of defining distinct organismtypes for each LFG, it is conceptualized to work with a Generic TypeModel (GTM). GTMis amodeling strategy that allows us to define the number of types inside each LFG, according to specific modeling needs. Our model was developed without parametrization of physical transport processes, but as a component of an integral modeling system — the MOHID Water Modelling System. Inside theMOHID systemourmodel is sufficiently generic to be used to model distinct marine ecosystems.

- by Marcos Mateus
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- Marine Ecology, Water quality, Ecological Modeling, Numerical Modelling

Ecological models for stream fish range in scale from individual fish to entire populations. They have been used to assess habitat quality and to predict the demographic and genetic responses to management or disturbance. In this paper, we conduct the first comprehensive review and synthesis of the vast body of modelling literature on the brown trout, Salmo trutta L., with the aim of developing the framework for a demogenetic model, i.e., a model integrating both population dynamics and genetics. We use a bibliometric literature review to identify two main categories of models: population ecology (including population dynamics and population genetics) and population distribution (including habitat–hydraulic and spatial distribution). We assess how these models have previously been applied to stream fish, particularly brown trout, and how recent models have begun to integrate them to address two key management and conservation questions: (i) How can we predict fish population responses to management intervention? and (ii) How is the genetic structure of fish populations influenced by landscape characteristics? Because salmonid populations tend to show watershed scale variation in both demographic and genetic traits, we propose that models combining demographic, genetic and spatial data are promising tools for improving their management and conservation. We conclude with a framework for an individual-based, spatially explicit demogenetic model that we will apply to stream-dwelling brown trout populations in the near future.

M. Niedziałkowska - K. Doan - M. Sykut - M. Górny - K. Stefaniak - N. Piotrowska - B. Jędrzejewska - B. Ridusch - S. Pawełczyk - F. Zachos - P. Mackiewicz - U. Schmölcke - P. Kosintsev - D. Makowiecki - M. Charniauski - R. Smith - D. Krasnodębski - U. Saarma - M. Arakelyan - N. Manaseryan - V. Titov - P. Hulva - A. Balasescu - R. Fyfe - J. Woodbridge - K. Trantalidou - A. Pisarenko - V. Dimitrijevic - J. Wilczyński - I. Foronova - G. Lipecki - A. Arabey - A. Stankovic Aim: The Expansion-Contraction model has been used to explain the responses of species to climatic changes. During periods of unfavourable climatic conditions, species retreat to refugia from where they may later expand. This paper focuses on the palaeoecology of red deer over the past 54 ka across Europe and the Urals, to reveal patterns of change in their range and explore the role of environmental conditions in determining their distribution. Location: Europe and western Asia to 63°E. Taxon: Red deer (Cervus elaphus). Methods: We collected 984 records of radiocarbon-dated red deer subfossils from the Late Pleistocene and the Holocene, including 93 original dates. For each deer sample we compiled climatic and biome type data for the corresponding time intervals. Results: During the last 54 ka changes in red deer range in Europe and the Urals were asynchronous and differed between western and eastern Europe and western Asia due to different environmental conditions in those regions. The range of suitable areas for deer during the Last Glacial Maximum (LGM) was larger than previously thought and covered vast regions not only in southern but also in western and eastern Europe. Throughout the period investigated the majority of specimens inhabited forests in the temperate climatic zone. The contribution of forests in deer localities significantly decreased during the last 4 ka, due to deforestation of Europe caused by humans. Mean January temperature was the main limiting factor for species distribution. Over 90% of the samples were found in areas where mean January temperature was above −10°C. Main conclusions: Red deer response to climatic oscillations are in agreement with the Expansion-Contraction model but in contradiction to the statement of only the southernmost LGM refugia of the species. During the last 54 ka red deer occurred mostly in forests of the temperate climatic zone. K E Y W O R D S environmental niche modelling, expansion-contraction model, forest habitat, Holocene, January temperature, Last Glacial Maximum refugia, palaeoecology, radiocarbon dating, temperate climatic zone, ungulates

- by Bogdan Ridush
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- Geography, Earth Sciences, Environmental History, Archaeozoology

This publication is by the Deutsche Gesellschaft für Internationale Zusammenarbeit through the Climate- relevant Modernization of Forest Policy and Piloting of Reducing Emissions from Deforestation and Forest Degradation (REDD) Project in the Philippines, funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) under its International Climate Initiative. The BMU supports this Initiative based on a decision of the German Parliament. For more information see http://www.international-climate-initiative.com. This study has been implemented by Fauna & Flora International in collaboration with the UNDP/GEF- funded NewCAPP, which cofinanced the field work for the biodiversity survey in Mt. Nacolod.

- by Noe Zuculito
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- Conservation, Ecological Modeling, Philippines, Biodiversity

Management of mixedwoods is advocated as an effective adaptation strategy to increase ecosystem resiliency in the context of climate change. While mixedwoods have been shown to have greater resource use efficiency relative to pure stands, considerable uncertainty remains with respect to the underlying ecological processes. We explored species interactions in Scots pine / European beech mixedwoods with the process-based model FORECAST Climate. The model was calibrated for two contrasting forests in the southwestern Pyrenees (northern Spain): a wet Mediterranean site at 625 m.a.s.l. and a subalpine site at 1335 m.a.s.l. Predicted mixedwood yield was higher than that for beech stands but lower than pine stands. When simulating climate change, mixedwood yield was reduced at the Mediterranean site (-33%) but increased at the subalpine site (+11%). Interaction effects were enhanced as stands developed. Complementarity dominated the Mediterranean stand but neutral or net competition dominated the subalpine stand, which had higher stand density and water availability. Reduced water demand and consumption, increased canopy interception, and improved water-use efficiency in mixtures compared to beech stands suggest a release of beech intra-specific competition. Beech also facilitated pine growth through better litter quality, non-symbiotic nitrogen fixation and above-and belowground stratification, leading to higher foliar nitrogen content and deeper canopies in pines. In conclusion, mixtures may improve water availability and use efficiency for beech and light interception for pine, the main limiting factors for each species, respectively. Encouraging pine-beech mixtures could be an effective adaptation to climate change in drought-prone sites in the Mediterranean region.

- by Brad Seely
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- Ecological Modeling, Forest Ecology And Management, Ecohydrology, Biological Sciences

An ever-growing number of IBMs have been developed by modellers, who aim to aid practitioners and inform a range of issues related to conservation, natural resource management, wildlife management and human socio-economic activities. The range of practitioners using IBMs to inform their decision-making processes include statutary authorities with responsibilities in environmental and natural resource management, non-governmental organizations such as conservation charities, and those interested in the sustainable use of natural resources. Thanks to advances in computational power, data availability and ecological theory, increasingly complicated, sophisticated IBMs can be produced. Yet this does not mean that these models will be more useful in informing environmental decision-making. IBMs typically require specialist computational knowledge to build and refine the model, and analyse the model outputs, and so practitioners are unlikely to have the requisite skills to use IBMs directly. Conversely, practitioners may have greater knowledge of the system being modelled, so their input into the modelling process is highly desirable. Thus, it is important that modellers and practitioners collaborate effectively to develop models which can address the key questions that practitioners are interested in. In this paper we highlight the uses of IBMs in environmental decision-making, identify potential obstacles to their successful use, and discuss how such obstacles can be overcome. We aim to help practitioners understand the potential benefits of IBMs, and to help modellers to understand how to develop IBMs which will better aid practitioners and inform environmental management and policy. We refer to a coastal bird IBM case study, from which general lessons can be learned.

- by Kevin Wood
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- Management, Landscape Ecology, Zoology, Environmental Science

1 Aims and scope of CREAM Current risk assessments are mainly based on ecotoxicological endpoints at the level of individual organisms, but according to the EU directives, the protection goal aims at achieving sustainable populations (European Commission 2002a, b;). Population-level effects depend not only on exposure and toxicity, but also on important ecological factors that are impossible to fully address empirically. At present, a number of testing approaches exist that provide endpoints on the community and the population level, respectively (nontarget arthropod and earthworm field tests, aquatic and terrestrial model ecosystem tests). However, not all fields and regulatory questions can be covered by these approaches. To fill these gaps and to enhance the scientific quality of ecological risk assessments, we suggest implementing mechanistic effect models (MEMs), as these also

El contenido de humedad de la vegetación es un parámetro crítico en la evaluación del peligro de incendios. Si bien se ha avanzado en comprender su rol en el comportamiento del fuego y en su estimación por teledetección, poco esfuerzo se ha dedicado a modelar su variabilidad temporal y espacial. Nuestro objetivo fue modelar la dinámica del contenido de humedad del combustible vivo (CHCV) en pastizales del NO de la Patagonia. Desde noviembre a febrero del 2013-2014, cada 15 días, tomamos muestras de biomasa verde en dos sitios de diferente grado de aridez separados por 60 km y determinamos su contenido de humedad. Mientras el sitio húmedo (SH; 580 mm.año-1 de Pp.) representa una estepa herbácea dominada por el coirón Festuca pallescens, el sitio xérico (SX; 250 mm.año-1) corresponde a una estepa arbustiva dominada por el coirón Pappostipa speciosa y los arbustos Mulinum spinosum y Senecio filaginoides. En cada sitio establecimos tres parcelas (500 m de lado) y dentro de cada una localizamos tres puntos en los que cosechamos 100 g de combustible vivo (de F. pallecens en el SH y de P. speciosa, M. spinosum y Senecio sp en el SX). Evaluamos la dinámica del CHCV a partir de un modelo de efectos mixtos controlando la estructura espacial de los datos, con autocorrelación temporal, y con modelado de la varianza. El CHCV disminuyó desde noviembre a febrero y fue diferente entre coirones y arbustos. Los arbustos comenzaron con un CHCV del 245% y terminaron con un 70%. En cambio, el CHCV de los coirones fue más estable y siempre menor al de arbustos variando entre el 65% y el 20%. La curva temporal del CHBV fue similar entre las dos especies arbustivas pero difirió entre F. pallescens (SH) y P. speciosa (SX). La variabilidad del CHCV fue mayor en los arbustos y disminuyó con el tiempo. Los resultados pueden ser atribuidos a las diferentes estrategias de uso del agua y a diferencias morfológicas entre las especies. Modelar correctamente la variabilidad del CHCV y conocer la eco-fisiología de la vegetación especies y puede aportar herramientas valiosas al manejo del fuego.

- by Facundo Oddi and +1
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- Plant Ecology, Fire Ecology, Ecological Modeling, Modelling

Ecological models for stream fish range in scale from individual fish to entire populations. They have been used to assess habitat quality and to predict the demographic and genetic responses to management or disturbance. In this paper, we conduct the first comprehensive review and synthesis of the vast body of modelling literature on the brown trout, Salmo trutta L., with the aim of developing the framework for a demogenetic model, i.e., a model integrating both population dynamics and genetics. We use a bibliometric literature review to identify two main categories of models: population ecology (including population dynamics and population genetics) and population distribution (including habitat-hydraulic and spatial distribution). We assess how these models have previously been applied to stream fish, particularly brown trout, and how recent models have begun to integrate them to address two key management and conservation questions: (i) How can we predict fish population responses to management intervention? and (ii) How is the genetic structure of fish populations influenced by landscape characteristics? Because salmonid populations tend to show watershed scale variation in both demographic and genetic traits, we propose that models combining demographic, genetic and spatial data are promising tools for improving their management and conservation. We conclude with a framework for an individual-based, spatially explicit demogenetic model that we will apply to stream-dwelling brown trout populations in the near future.

- by Philippe Baret
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- Zoology, Population Genetics, Ecological Modeling, Ecology

Dense surface blooms of toxic cyanobacteria in eutrophic lakes may lead to mass mortalities of fish and birds, and provide a serious health threat for cattle, pets, and humans. It has been argued that global warming may increase the incidence of harmful algal blooms. Here, we report on a lake experiment where intermittent artificial mixing failed to control blooms of the harmful cyanobacterium Microcystis during the summer of 2003, one of the hottest summers ever recorded in Europe. To understand this failure, we develop a coupled biological–physical model investigating how competition for light between buoyant cyanobacteria, diatoms, and green algae in eutrophic lakes is affected by the meteorological conditions of this extreme summer heatwave. The model consists of a phytoplankton competition model coupled to a one-dimensional hydrodynamic model, driven by meteorological data. The model predicts that high temperatures favour cyanobacteria directly, through increased growth rates. Moreover, high temperatures also increase the stability of the water column, thereby reducing vertical turbulent mixing, which shifts the competitive balance in favour of buoyant cyanobacteria. Through these direct and indirect temperature effects, in combination with reduced wind speed and reduced cloudiness, summer heatwaves boost the development of harmful cyanobacterial blooms. These findings warn that climate change is likely to yield an increased threat of harmful cyanobacteria in eutrophic freshwater ecosystems.

- by Klaus Klaus
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- Aquatic Ecology, Climate Change, Limnology, Turbulence

- by Emma Agyapong
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- Biostatistics, Ecological Modeling, Urban Ecology, Vegetation Ecology