Dalva Matos | UFSCar - Federal University of São Carlos (original) (raw)

Papers by Dalva Matos

In the Neotropics, especially in southeastern Brazil, due to sugarcane and eucalypt monocultures,... more In the Neotropics, especially in southeastern Brazil, due to sugarcane and eucalypt monocultures, and the expansion of industries and the largely unplanned urban centers entire aquatic ecosystems are threatened. Nonetheless, benthic macroinvertebrates are important biomonitoring tools to assess the biotic and abiotic condition of endangered freshwater environments. In this study we address how benthic macroinvertebrate diversity respond to the combined effect of local environmental factors. We also aimed to evaluate how benthic macroinvertebrates diversity respond according to the habitat integrity. We expected to find higher diversity in the sampling sites with higher habitat integrity (i.e., low potential of hydrogen, electrical conductivity and water temperature, and high canopy coverage and concentration of dissolved oxygen). By using a multivariate approach (i.e., PCA) and a regression analysis (i.e., Linear Mixed-Effect Model) we were able to address the combined effect of loc...

Oecologia Australis, 2014

Roads are one of the main threats to mammal species conservation. Identifying relationships betwe... more Roads are one of the main threats to mammal species conservation. Identifying relationships between landscape and road-kill patterns is necessary to build predictive models and to propose mitigation measures, particularly in heterogeneous landscapes. We choose three species of medium-sized mammals with high dispersal capacity and opportunistic habitat use as representatives to understand which landscape features affect road-kills: the crab-eating fox Cerdocyon thous , the maned-wolf Chrysocyon brachyurus , and the hare Lepus europaeus. The study was done over two consecutive years on the SP-225 highway in the State of Sao Paulo, southeastern Brazil. Road-kill data were collected on a daily basis, every three hours, by car travelling at 50-60 km/h. We used a logistic regression considering, as dependent variable, the occurrence of road-kills for each species, and as independent variables, the following landscape features: sugarcane fields cover, pasture cover, native vegetation cover, forestry cover, orange groves cover, urban area, and distance to the nearest river. Three buffer sizes were created around each road-kill occurrence to evaluate the effect of spatial scale. Model selection using Akaike Information Criterion with correction for small samples (AICc) showed that the road-kill incidence of Chrysocyon brachyurus was positive associated to urban area at larger scale, and for Cerdocyon thous and Lepus europaeus was found a positive association to forestry cover at different scales. For C. thous and L. europaeus , some models worth interpreting included water bodies area, distance to the nearest river and sugarcane fields cover. Matrix permeability and river proximity could be used to indicate sites to apply mitigation measures to road-kill for these mammal species in the Brazilian Savanna.

Brazilian Journal of Biology, 2014

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Mo... more Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna. We measured the biomass of fronds, rhizomes and above-ground litter. We also compared the density, length and biomass of fronds from this Brazilian study with similar data of P. esculentumsubsp. arachnoideum derived from Venezuela and P. aquilinum from Europe. P. esculentum subsp. arachnoideum showed a wide response range. We found a negative relationship between frond and necromass, indicating a negative feedback effect, while a positive relationship was observed between frond and rhizome biomass. The continental comparison of relationships showed that Pteridium responds in a different way i...

Biota Neotropica, 2013

Invasive species can cause structural and functional changes in their non-native habitats, such a... more Invasive species can cause structural and functional changes in their non-native habitats, such as changes in the trophic chain. We describe ramet herbivory of butterfly ginger, an aggressive aquatic weed in Brazil, by capybaras in a floodplain area of a Cerrado reserve. This is the first record of herbivory of H. coronarium in invaded areas. Capybaras could be using the butterfly ginger as habitat and as a food resource, which could cause changes in apparent competition between these invasive and native macrophytes.

Revista Ciência Agronômica, 2014

In areas of the Cerrado-Pantanal ecotone in Brazil, the soil displays features which are inherent... more In areas of the Cerrado-Pantanal ecotone in Brazil, the soil displays features which are inherent to the processes of soil formation, both of the Central Plateau and the Pantanal Plain. Given this premise, the area should be noteworthy for its high level of edaphic heterogeneity. The present study aimed to determine the physical, chemical and physico-hydric attributes that best explain the heterogeneity of soils in areas of the Cerrado-Pantanal ecotone, and to assess whether these attributes differ between the studied fragments and between the Cerrado soils of the Central Plateau and of the Pantanal Plain. One hundred and sixty soil samples were collected and 11 profiles described for five areas of the Cerrado-Pantanal ecotone (15º43' S, 56º04' W). The following classes were identified: typic Concretionary Petric Plinthosol; typic Lithoplintic Petric Plinthosol; typic dystrophic Yellow Latosol; dystrophic Yellow Latosol with plinthite, the last three not yet having been described for this region. The chemical attributes CEC, M, OM, K, P, Mg, Ca and Mn explained 40.49% of the variability of the soils in the region under study, whether differing or not between the studied fragments. Spatial distribution of the attributes varied between random and aggregated, with the chemical attributes CEC, K, Ca and Mg being similar to soils of the Pantanal Plain. Whereas Al, P and Mn, as well as the hydric variables, were similar to the Plateau. On the other hand, the average organic matter content, pH, gravel and pebbles, were characteristic of both the Plateau and the Plain.

Ecosystem Services, 2012

Ecosystem services science has developed at a fast rate in Latin America, a region characterized ... more Ecosystem services science has developed at a fast rate in Latin America, a region characterized by a high biological and cultural diversity, strong emphasis in foreign investment, and high socioeconomic inequities. Here we conducted the following analyses at the regional and national scales: (1) how and when did the study of ecosystem services arise in each country?, (2) what is our present understanding of ecosystem service supply, delivery to societies, and social and economic values?, (3) what is the state of the art in integrating tradeoffs among services and in using interdisciplinary perspectives?, and (4) how has ecosystem service research been connected to policy design or management for sustainability? A large literature review (4 1000 references) showed that in Latin America ES supply and links to policy have been the most frequently assessed. Overall, emphasis has been placed on a few services, namely carbon and water. Payments for ecosystem services have received considerable attention in the region, though with strong differences across nations and with important limitations in their application. The future of the ecosystem service paradigm in Latin America will largely depend on its capacity to demonstrate effectiveness in meeting both conservation and development goals.

Plant Ecology, 2013

The effect of the adjacent non-forested environment on the forest near the edge, edge influence (... more The effect of the adjacent non-forested environment on the forest near the edge, edge influence (EI), is an important impact in fragmented landscapes and is believed to vary with factors such as forest structure and edge contrast. In order to improve our understanding of the factors governing the variability in EI, we studied microclimate and vegetation at cerrado edges surrounded by variable land uses in southeastern Brazil, a system with both forest and savanna fragments. We determined the significance, magnitude and distance of EI on microclimate, vegetation structure and grass biomass which we measured along five transects perpendicular to fourteen edges in forest or savanna next to different land uses. We introduce a quantitative measure of edge contrast that considers land uses at different distances from the same edge (e.g., a firebreak between a forest edge and a plantation) and verified whether edge contrast is correlated with EI in this system. Notwithstanding the large variation in EI among variables and study sites, there were some similarities in the patterns of EI between forest and savanna edges. Edge contrast was successfully quantified by our measure but was only correlated with EI on moisture and grass biomass. Our results point to the high variability in EI within a region. Our quantitative measure of edge contrast may be useful in explaining variability in EI. However, much unexplained variation remains in the highly fragmented cerrado system which is affected by EI in both forest and savanna fragments.

mammalia, 2014

In studies on frugivory and seed dispersal, it is frequently assumed that individual frugivores o... more In studies on frugivory and seed dispersal, it is frequently assumed that individual frugivores of the same population behave as equivalents. However, there is growing evidence from dietary studies pointing out that, in many natural populations, individuals use different subsets of the total resource pool. As heterogeneity in foraging behavior and food selection may affect the outcome of the seed dispersal process, we tested whether yellow-shouldered bats Sturnira lilium (E. Geoffroy St.-Hilaire, 1810), the key neotropical seed dispersers, show interindividual variations in fruit preferences. Thirty individuals were submitted to cafeteria trials in a flight tent, when they were offered fruits of Solanum variabile Mart. (Solanaceae) Cecropia pachystachya Trec. (Urticaceae), and Piper aduncum L. (Piperaceae), which belong to the favorite genera consumed by S. lilium. Although S. variabile had the highest consumption rates on average, there were variations among individuals in the fruits consumed in the second and third places. These findings, together with interindividual differences in foraging areas observed in the same population, may be interpreted as preliminary evidence of individual specialization. As a possible consequence, frugivorous bats of the same population, despite being all legitimate dispersers, may differ in their efficiency.

Ecology, 1999

The role of density dependence in the population dynamics of tropical trees has been a subject of... more The role of density dependence in the population dynamics of tropical trees has been a subject of considerable debate. Here, we present data on the demography of the edible palm Euterpe edulis, classified into seven size categories and monitored over three years. On average, each adult palm contributed 98 seedling recruits per year into the population. The pattern of mortality was similar to that of other palms, with mortality being highest among the smallest plants. Those plants with a diameter at soil level Ͼ20 mm had an annual mortality Ͻ7%. Density dependence was found to act only on the seedling stage of the life cycle. The probability of survival and transition of seedlings to the next size class were affected both by the density of seedlings and the presence of conspecific adults. Matrix modeling indicated that the true finite rate of population increase () was 1.28 and that the observed reverse ''J''-shaped size distribution of plants was a consequence of the density dependence operating in the population. Elasticity analysis showed that the survival elements in the matrix contributed most to the value of , and that the position of the transition matrix in growth-survival-fecundity (G-L-F) space was influenced by density. The matrix model incorporating density dependence predicted size distributions and densities approximating the maximum observed in the field. Spatial simulations indicated that the predictions from the matrix model relating to the size structure of plants are robust, but that the predictions of densities are sensitive to the precise spatial dynamics of the population.

Urban Ecosystems, 2002

National Park of Tijuca in Rio de Janeiro (Brazil) is about 3,300 ha and considered the largest u... more National Park of Tijuca in Rio de Janeiro (Brazil) is about 3,300 ha and considered the largest urban forest in the world. Its floristic composition is typical of Atlantic Rain Forest. The reserve is being altered because of fire occurrences and urban expansion. This study identified locations and causes of forest fires, and makes management recommendations to restore damaged areas.

Flora, 2017

• We demonstrate that a "heterogeneity enhancer" increase diversity in the Restinga, a stressful ... more • We demonstrate that a "heterogeneity enhancer" increase diversity in the Restinga, a stressful tropical ecosystem. • Our results highlight the importance of evaluate the role played by individual species at different diversity scales. • Plant-plant interactions may increase diversity. • Conservation effort towards both the area and nurse species are crucial to maintaining plant diversity in Restinga forest.

forest fragmentation is concerned with understanding of the environmental aspects that can induce... more forest fragmentation is concerned with understanding of the environmental aspects that can induce changes in biodiversity. Despite its importance, there are relatively few studies focusing on the microenvironmental status of fragments, especially fragments of tropical forest of less than 100ha (Harrington et al. 1997, Turton & Freiburger 1997, Tabanez et al. 1997, Viana et al. 1997). Most of the literature on forest fragmentation is derived from larger fragments, specially those in Amazonia (Kapos et al. 1993, Kapos et al. 1997, Scariot 1999, 2000, Laurance et al. 2001) whose past and present status is completely different from the Atlantic rain forest. The Atlantic rain forest, which originally occurred in a large expanse parallel to the Atlantic Ocean, is presently reduced to 8% of its original size (SOS Mata Atlântica 1998). According to Tanizaki & Pedrosa (1998) most forest fragments (87%) still found in Rio de Janeiro state are at most 2 km2 which corresponds to 11.7% of the to...

Oecologia

High propagule availability compared to native species is often critical to invasion success, but... more High propagule availability compared to native species is often critical to invasion success, but it is unclear if this has contributed to invasions by African grasses in Neotropical savannas. We compared patterns of occurrence in the vegetation, seed rain and seed bank among African and native grasses in Cerrado sites in southeastern Brazil. In grasslands and savannas, we obtained the abundance of grasses in the vegetation, in the seed rain (monthly for one year) and in the seed bank (rainy and dry season), and assessed seed limitation and relationships among compartments. Invasive grasses showed low abundance in all compartments and high seed limitation in grasslands, where the seed bank and seed rain were dominated by small-seeded native grasses, but were at least as abundant as the natives in the seed bank and seed rain in savannas, mostly due to high abundance of Melinis minutiflora at these compartments. Native grasses dispersal occurred in the rainy season, whereas invasive grass dispersal occurred from mid rainy to mid dry season (Urochloa decumbens) and in the dry season (M. minutiflora). Melinis minutiflora showed a more persistent seed bank than U. decumbens and natives in savannas. Abundance of invasive and most of the native grasses in the vegetation was positively related to their abundance in the seed rain. Differences in seed production, the timing of seed dispersal and seed bank persistence compared to native grasses seem to favour invasive African grasses in the Cerrado, but this role may differ between grasslands and savannas.

Plant Ecology & Diversity

ABSTRACT Background: Promoting changes in abiotic conditions and ecosystem processes, such as dec... more ABSTRACT Background: Promoting changes in abiotic conditions and ecosystem processes, such as decomposition, is a mechanism by which some exotic plant species displace native plants and become invasive. Aims: We monitored ramets of Hedychium coronarium over 30 months to estimate the litter decay rate, biomass dynamics and litter accumulation over time in riparian sites invaded by the species in southeastern Brazil. Methods: We measured the number, height, emergence and mortality of ramets in three environments invaded by H. coronarium (natural, rural and urban). We also measured litter decay in situ and in in vitro experiments. We used sinusoidal models to describe height fluctuation and exponential models to simulate litter decay and litter accumulation. Results: Ramets of H. coronarium showed high seasonal variation in terms of height and emergence, as well as low litter decay. Accordingly, our models predicted high litter production and a seasonal pattern of litter accumulation in invaded sites. Conclusions: H. coronarium produces a great amount of litter, which shows slow decay and hence seems to affect decomposition processes. Investigating seasonal variation on the effects of invasive species on ecosystem functioning shed light on the factors driving the success and impact of invasive plants.

Plant Ecology

Invasive grasses are an important threat in tropical savannas and grasslands and may be affected ... more Invasive grasses are an important threat in tropical savannas and grasslands and may be affected by natural and anthropogenic features of the environment. They may affect native species at a variety of scales, but a spatially explicit assessment of their effects is lacking. We studied the spatial pattern of native and invasive graminoids in Brazilian cerrado in southeastern Brazil and assessed the effects of vegetation type, elevation, and edges. We sampled native grasses, native sedges, and two invasive grass species (Urochloa decumbens and Melinis minutiflora) along three 301- to 1334-m-long transects encompassing grassland, forest, and savanna. We used wavelet transforms, generalized additive models, and null model simulations for analysis. Invasive grasses were mostly found in open vegetation. Neither native nor invasive species were consistently affected by elevation or edges. Much of the spatial variation could be explained by small-scale autocorrelation, but M. minutiflora had a more heterogeneous pattern than U. decumbens. Invasive grasses were negatively related to native ones at a variety of scales, from 1 to 66 m, and we observed both positive and negative relations between the two invasive species, with positive ones a finer scales. We hypothesize that spatial pattern characteristics of different invasive species may be related to their invasion potential.

Plant and Soil

AimsTo identify the role of soil properties and groundwater depth on the structure of a fire-prot... more AimsTo identify the role of soil properties and groundwater depth on the structure of a fire-protected neotropical savanna. We aimed to address: i) What is the contribution of soil properties and groundwater depth to the physiognomic variation? ii) Are these factors associated with patterns in woody structure? iii) Are open physiognomies maintained by shallow groundwater?MethodsWe measured soil properties, tree basal area, density, richness, and monitored groundwater depth in two types of grassland and three types of savanna during two years. We also investigated vegetation dynamics over three decades using remote sensing.ResultsThere were no differences in soil properties between physiognomies, except for a greater soil organic matter content in flood-prone grasslands. Woody structure attributes were related to groundwater depth and clay content at coarse spatial scales (1 ha) and to groundwater depth and organic matter at fine spatial scales (100 m). Open savannas and grasslands remained unchanged and occurred where the groundwater depth was lower than 4 m.ConclusionSoil fertility did not drive the spread of closed physiognomies. Low clay content and shallow groundwater depth tended to decrease the woody cover, favoring the occurrence of open savannas and grasslands.

Journal of Vegetation Science

From individuals to communities: how singleton invasive pine saplings lead to biodiversity change... more From individuals to communities: how singleton invasive pine saplings lead to biodiversity change in the Brazilian Cerrado hotspot Isolated pines restructure plant community

Perspectives in Ecology and Conservation

The subject of biological invasions is well-recognized, especially due to the associated impacts,... more The subject of biological invasions is well-recognized, especially due to the associated impacts, but different interpretations exist about the concept of invasive species. These are usually known as exotic species that proliferate intensely, spread rapidly and persist as dominant in the new community. However, some native species may behave the same way and bring serious ecological and economical losses. Nonetheless these native species may not attract management efforts and specific policies, partially because of the assumption that native species are harmless. We review the concepts of invasive species and show the potential harm of overabundant populations of native species, which we name "superdominant" species. Based on literature review we demonstrated the lack of information on the Brazilian super-dominant plant species. Considering all kinds of published material and knowledge from our own experience we selected 16 Brazilian native terrestrial plants that most frequently show unexpectedly intense growth and dominance in their original habitats. We discuss the factors that may have triggered atypical dominance, negative impacts of these species on the native biodiversity and ecosystems, and future trends. Anthropogenic disturbances are the main drivers of the explosive population growth of these native species, especially habitat fragmentation, forest gap formation, and wildfires. The absence of legal support to deal with super-dominant native species is probably the main reason for the lack of disclosure of the subject. In the future scenario of climate change we expect the intensification of the phenomenon. Strategies for early detection and control need to be fast developed.