Species In Area Research Articles

2021 Turkey mega forest Fires: Biodiversity measurements of the IUCN Red List wildlife mammals in Sentinel-2 based burned areas

Mega wildfires are one of the environmental disasters worldwide. This study evaluates the pre-fire species diversity and the indirect effects, including habitat loss for one of the largest wildfires in Manavgat (Antalya-Turkey) in 2021, with a two-step methodology. Here, (1) burnt areas in the Manavgat district (2021) were detected with remote sensing data from Sentinel-2A by delta Normalized Burn Ratio calculation for a selected area in Google Earth Engine, and (2) mammals' habitat vector data of International Union for Conservation of Nature (IUCN) Red List were integrated into Habitat and Biodiversity modelling of Terrset to analyze the alpha, beta, gamma diversity and Range Restriction Index for the wildfire region. In the total 4210 km2 study area, 696 km2 of the area was damaged by different fire severity; also, there were 56 mammal species' habitats here. These species include bats (i.e. Nyctalus leisleri), felids (i.e. Felis chaus), rodents (i.e. Rattus norvegicus) and large mammals (i.e. Ursus arctos). 88 % of these species are in IUCN's Least Concern category. The remaining classes are Near Threatened (3.7 %) and Vulnerable (7.4 %). This study also indicated that the burnt area's species richness does not totally consist of endemic species. Therefore, pre-fire species richness analyses of this study can be a base for further studies about the species' post-fire activity and occupancy.Furthermore, the 2021 mega wildfires show us the necessity of wildfire monitoring and risk studies in the entire Mediterranean ecosystem to evaluate the risks to the Sustainable Development Goals. Therefore, post-fire spatial data, fire migration monitorization, and recording of the species' activities should be performed temporally. In this way, the ability of wildlife's recovering, and the direct and indirect effects of the fire will be examined for ecosystems in the long term.

Island size predicts mammal diversity in insular environments, except for land‐bridge islands

AbstractInsular environments are among the most endangered ecosystems as they face a myriad of anthropogenic stressors. Forest mammals perform a wide range of ecological services, with their persistence being vital for ecosystem functionality in both natural and artificial islands. Studies revealed that shrinkage in island size usually leads to the decay of mammal species richness and abundance in patchy landscapes. However, mammal species‐area (SARs) and abundance‐area (AARs) relationships can differ among insular environments: oceanic, fluvial, artificial, and land‐bridge islands (i.e., natural islands connected to the mainland). Large dams create vast insularized landscapes after river impoundment, leading to pervasive habitat loss and potentially causing even worse biodiversity losses than other insular systems. We conducted an extensive literature search and used meta‐analysis techniques to quantify the magnitude of SAR and AAR for forest mammals across different archipelago landscapes worldwide. After a screening process, we ended up with 26 studies comprising 55 different effect sizes representing the magnitude of SARs and AARs. Our global analysis unveiled a positive relationship between effect sizes and island area, with mammal species richness and abundance increasing in fluvial, oceanic, and artificial islands accordingly with island area, but not in land‐bridge islands. These results demonstrate that, except for land‐bridge islands, SAR and AAR are still fair models to predict mammal diversity. These results could improve the prediction of SAR and AAR in insular environments under habitat loss scenarios and propose sound conservation strategies since the rate at which insular communities have been lost is presently unknown.

Tree species composition and diversity in natural temperate forests of the North-Western Himalayas

The present study was undertaken in the natural temperate Himalayan forests of Himachal Pradesh, India, to assess the tree species composition and diversity. For this purpose, six major forest types (FT) viz., FT1- Upper Himalayan Pinus roxburghii forest, FT2- Quercus leucotrichophora forest, FT3- Low-level P. wallichiana forest, FT4- Moist C. deodara forest, FT5- Western Mixed Coniferous Forest, FT6- Pinus gerardiana forest were selected. Detailed sampling was carried out in these forest types, and the sample plots in each forest type were laid out using the stratified random approach. Tree stem density varied from 191.11 N ha−1 (FT6) to 441.11 N ha−1 (FT2), whereas the tree total basal cover varied from 20.01 m2 ha−1 (FT6) to 47.59 m2 ha−1 (FT5). The diversity indices reflected that a total of 21 tree species (16 genera, 11 families) were identified, with tree species richness ranging from 3 (FT6) to 9 (FT1 & FT5). The forest type FT5 recorded the maximum Shannon index of diversity (2.36), Simpson Index of diversity (0.75), Margalef's Index of richness (1.37), pielou equitability (0.74), menheink index of species richness (0.49), whereas the highest Shannon Index of diversity (0.73) and species heterogeneity (0.85) in FT6 forest type. Furthermore, dominance-diversity (d-d) curves drawn that all the six forest types showed geometric curves reveals that one or two tree species are dominant in a particular forest type. Simultaneously, the research area's species diversity, tree stem density, and tree total basal cover were equivalent to those seen in other sections of Western Himalayas.

Multiple Environmental Factors Increase the Niche Complexity and Species Diversity of Brachyuran Crabs in an Intertidal Algal Reef Ecosystem in Northwestern Taiwan.

Algal reefs are one of the world's rare and poorly understood ecosystems. They are mainly distributed in the Mediterranean Sea, but one notable exception-an intertidal algal reef ecosystem in northwestern Taiwan-stretches for 27 km along the coast of Taoyuan, making it probably the largest algal reef coast found in shallow water. Despite the reef's rarity and striking characteristics, the coastal land that it is part of has undergone a series of developments and is now surrounded by industrial parks. Brachyuran crabs are one of the most abundant and visible groups of organisms in the intertidal zone. In the present study, we investigated the brachyuran crab community in this reef to provide a more detailed record of brachyuran crab species compositions in this intertidal algal reef ecosystem and illustrate the characteristics of this understudied ecosystem by comparing its species diversity and abundance with three natural variables- sampling time, tidal level, and season-in a wildlife refuge and north of the refuge. Two methods were used in the study: a qualitative method (to determine the species richness) and a quantitative method (to estimate the population density). We identified a total of 52 brachyuran species from 13 families in the habitats. The highest species richness was found in Datan G2, north of the wildlife refuge. The crab species composition in this algal reef is different from its compositions in coral and rocky reefs. Our analysis indicated that the species abundance is affected by multiple factors, and a single investigation is not enough to reflect the true population density of brachyuran crabs on this reef. In addition, we found that the sites outside the wildlife refuge were in much better condition than those in the wildlife refuge, and should therefore be included in the wildlife refuge. In particular, Datan, located north of the wildlife refuge, had the highest species richness, and the area's species composition was different from that of the nearby wildlife refuge. Thus, we strongly recommend that a) the Datan area be protected to maintain this high crab diversity and b) further research be performed to better understand brachyuran crab biology in the intertidal algal reef ecosystem.

Fragment size and the disassembling of local bird communities in the Atlantic Forest: A taxonomic and functional approach

Habitat loss is the primary driver of the decline of biodiversity in ecological communities. However, which ecological processes are implicated in the removal of species following habitat loss, i.e. the disassembling of the community, remains unclear in many ecosystems. We address this question by investigating how the taxonomic and functional diversity of bird assemblages are related to fragment size in the Atlantic Forest from northeastern Brazil. We used complementary metrics of diversity and a randomization procedure to test whether changes in diversity result from either random or deterministic processes, such as limiting similarity or habitat filtering. The species–area (SAR) and functional richness–area (FAR) relationships were positive, as expected. However, the FAR had a lower slope than the SAR, which indicates a slower loss of functional richness than that predicted by the loss of species richness. Communities in smaller fragments contain more functionally overdispersed species and a more even distribution of abundance. These results indicate that limiting similarity drives the disassembling of bird assemblages in small fragments of the Atlantic Forest, which presumably reflects increased competition. This dynamic tends to reduce functional redundancy in the impoverished assemblages, with potentially deleterious consequences for ecosystem functioning and forest conservation.

Species richness and patterns of overdispersion, clustering and randomness shape phylogenetic and functional diversity–area relationships in habitat islands

AbstractAimThe aim of this study was to evaluate how the area of habitat islands influences multiple facets of diversity.LocationSouthern Brazil.TaxonBirds.MethodsUsing an Information Theoretic approach, we compared the fit of 20 diversity–area relationship (DARs) models in three habitat island systems. We tested for the best‐fit model, model‐family, shape and the presence/absence of an asymptote. We used species richness (SR), Faith's phylogenetic diversity (PD) and Faith's functional diversity (FD) to assess species–area (SARs), phylogenetic (PDARs) and functional diversity–area relationships (FDARs). We controlled for the effect of SR in PD and FD via null models to assess PDARs and FDARs independently of SR and to explore the influence of phylogenetic and functional randomness, clustering and overdispersion.ResultsPDARs and FDARs built with PD and FD resembled SARs and were all best fitted by convex or sigmoidal, upwards oriented, non‐asymptotic models. Controlling for SR in diversity indices produced flat or downwards oriented, weak PDARs and FDARs, which were best fitted by convex, non‐asymptotic models or the linear model. Taxonomic diversity accumulated faster with area than functional diversity, which accumulated faster than phylogenetic diversity. Randomness and clustering patterns prevailed in shaping PDARs and FDARs relative to overdispersion.Main conclusionsControlling for SR in PD and FD affects DARs patterns and the strength of the relationships. Irrespective of this influence of SR, a few simple models of the power and exponential model‐families best fit DARs. Model parameters reveal differences in the response of each facet of diversity to increases in area, highlighting the complementary nature of DARs. When considered independently of SR, PDAR and FDAR patterns largely reflect the broad variation of phylogenetic and functional diversity in small islands. This suggests that the ecological processes that generate phylogenetic and functional overdispersion and clustering operate at contrasting spatial scales.

When the species–time–area relationship meets island biogeography: Diversity patterns of avian communities over time and space in a subtropical archipelago

AbstractAimThe species–area (SAR) and species–time relationships (STR) are of vital importance in community ecology. Previous studies suggest that a unified, general species–time–area relationship (STAR) may hold, with non‐independent scaling of richness across space and time. Most STAR studies to date have considered species accumulation curves in relatively homogeneous habitats. Here, we test the generality of the STAR in an island system and assess how factors other than area influence species richness, accumulation and turnover through time.LocationThousand Island Lake, China.MethodsWe surveyed bird communities on 36 islands using line transects, and calculated annual species richness of breeding birds from 2007 to 2015. We built island STAR models at island (island STAR; ISTAR) and transect levels (local community–time–area relationship; LCTAR). We employed partial correlations and multiple regressions to examine potential influences of island attributes other than area (i.e. isolation, edge effect and habitat richness) on slopes of STRs.ResultsISTAR and LCTAR models explained 88.8% and 83.1% of total variance, respectively, and both models have a negative space–time interaction. Richness scales comparably in space and time, for both whole‐island and transect‐level analyses. The partial correlation analysis showed that distance to mainland and perimeter‐to‐area ratio are significantly positively correlated with the time scalar (w), and habitat richness and w are negatively correlated. Multiple regression models identify perimeter‐to‐area ratio as particularly influential.Main conclusionsThe STAR pattern generalized to an island system where species turnover is high, indicating an interdependency of time and space in determining species richness. Islands have attributes other than area that influence patterns of species accumulation and turnover through time. Ecologists should consider the interdependence of space and time when characterizing species richness patterns.

Diversity and production in an Afromontane Forest

This contribution evaluates the effect of forest structure and tree species diversity on plot productivity and individual tree growth in the unique Knysna forests in Southern Africa using mapped tree data from an observational study that has been re-measured over a period of 40 years. The effects of tree species diversity and forest structure on tree growth and forest production are evaluated on three levels of resolution: a) the forest community (canopy, sub-canopy species), b) the subplots (number of trees per ha, skewness of the diameter distribution, diameter coefficient of variation) and c) the immediate neighborhood of selected reference trees (“Mingling”, “Dominance”, Aggregation” and “Size Variation”). An analysis of the community level identified two distinct clusters, one including dominant/canopy species with the highest growth rates and a greater variation of growth, and another cluster which includes the remaining subcanopy species which have a smaller maximum size and lower rates of growth. The area-based structure variables on plot level have a highly significant effect on total basal area growth. However, the effects of forest density and species richness on productivity were not straight forward. Maximum basal area production of about 0.75 m2/ha/year is achieved at medium levels of richness (around 20 species per ha) and medium levels of density (around 30 m2/ha basal area) using percentile regression estimates. The relative “Dominance” of a selected reference tree had a highly significant effect on individual tree growth on all investigated species. Other neighbourhood structure variables were only occasionally significant or not significant at all. This contribution presents a new theoretical framework for analysing natural forests that includes community, plot and neighborhood variables of forest structure and diversity, and a first specific analysis of the structure and dynamics of the Knysna Afromontane Forest, based on a unique set of longterm observations. The species-area (SAR) model developed in this study, represents a new general approach that can be used to derive a common standard of tree species diversity for different plot sizes, the species richness per hectare.

Estimates of species extinctions from species–area relationships strongly depend on ecological context

Species–area (SAR) and endemics–area (EAR) relationships are amongst the most common methods used to forecast species loss resulting from habitat loss. One critical, albeit often ignored, limitation of these area‐based estimates is their disregard of the ecological context that shapes species distributions. In this study, we estimate species loss using a spatially explicit mechanistic simulation model to evaluate three important aspects of ecological context: coexistence mechanisms (e.g. species sorting, competition–colonization tradeoffs and neutral dynamics), spatial distribution of environmental conditions, and spatial pattern of habitat loss. We found that 1) area‐based estimates of extinctions are sensitive to coexistence mechanisms as well as to the pattern of environmental heterogeneity; 2) there is a strong interaction between coexistence mechanisms and the pattern of habitat loss; 3) SARs always yield higher estimates of species loss than do EARs; and 4) SARs and EARs consistently underestimate the realized species loss. Our results highlight the need to integrate ecological mechanisms in area‐estimates of species loss.

An overhaul of the species–area approach for predicting biodiversity loss: incorporating matrix and edge effects

Summary 1. Species–area (SA) models have often been used to predict biodiversity loss resulting from habitat loss. This application of SA models hinges on two fundamental assumptions: the resultant landscape matrix is inhospitable to the taxa of interest; and edge effects do not factor into extinction risks. Despite growing consensus that these assumptions are unrealistic, the SA approach continues to be used in assessments of biodiversity decline and conservation planning. 2. We propose an overhaul of the SA approach by accounting for taxon‐specific responses to landscape‐specific matrix quality and deleterious effects of habitat edges. We pitted nine variants of an improved SA model (calibrated for edge and/or matrix) against two variants of the conventional model (calibrated with island or continental z values) to predict species extinction and endangerment in 15 tropical biodiversity hotspots. 3. The matrix‐calibrated SA model received the highest Akaike’s Information Criterion weight (birds: 66·8%; mammals: 63·3%), which reflects the weight of evidence in support of it being the most parsimonious model given the set of candidate models and data considered. Additionally, the matrix‐calibrated (MC) model produced species extinction predictions that were the most accurate and least biased. 4. The second best model (for both birds and mammals) was one that simultaneously corrected for matrix and edge effects. 5. The conventional SA model (particularly when calibrated with an island z value) performed worse than the matrix‐calibrated and/or edge‐corrected models. 6. Synthesis and applications. Our results suggest that accounting for the landscape matrix per se is a sufficient and significant improvement to the SA approach in terms of assessing species extinction risks from land‐use change. More importantly, given that the MC model was also the most parsimonious model (in that it requires only one additional model parameter than the conventional SA model), it could prove to be a cost‐effective heuristic tool for conservation scientists and decision makers to accurately evaluate extinction risks resulting from land‐use decisions. We argue that, henceforth, the MC model, which takes account of both the extent of deforestation and quality of the resultant matrix, should replace the conventional SA model for predicting biodiversity loss.

Patterns of sponge biodiversity and abundance across different biogeographic regions

Few studies have compared the underlying nature or structure of marine communities and assemblages across broad spatial scales, despite the importance of such comparisons in understanding global scale responses to environmental change and biodiversity conservation. The aim of this study was to examine the consistency of relationships between sponge abundance and richness on the undersides of boulders (to control for multiple confounding factors) in relation to space availability (boulder size) in three widely separated biogeographic regions. Sponges followed typical species-area (SA) relationships irrespective of site or ocean and we consistently found no decrease in sponge richness at larger boulder sizes. We also found reliable underlying density–area (DA) relationships, with larger boulders supporting more sponge patches at all sites. Although the general SA and DA relationships were similar between oceans and sites, the exact nature of these relationships in terms of the actual species present per unit area, total number of species present or density differed between sites. There were no consistent differences between SA and DA relationships at each locality, suggesting that although disturbance (particularly wave action) regimes may play an important role in controlling sponge biodiversity and abundance, its effects are manifested differently at local-scales. Even though boulders have received a considerable amount of research effort over the past three decades, this is the first study to examine the consistency of DA and SA relationships between ocean basins, finding similar relationships.

SYNERGISTIC INTERACTIONS BETWEEN EDGE AND AREA EFFECTS IN A HEAVILY FRAGMENTED LANDSCAPE

Both area and edge effects have a strong influence on ecological processes in fragmented landscapes, but there is little understanding of how these two factors might interact to exacerbate local species declines. To test for synergistic interactions between area and edge effects, we sampled a diverse beetle community in a heavily fragmented landscape in New Zealand. More than 35,000 beetles of approximately 900 species were sampled over large gradients in habitat area (10(-2) 10(6) ha) and distance from patch edge (2(0)-2(10) m from the forest edge into both the forest and adjacent matrix). Using a new approach to partition variance following an ordination analysis, we found that a synergistic interaction between habitat area and distance to edge was a more important determinant of patterns in beetle community composition than direct edge or area effects alone. The strength of edge effects in beetle-species composition increased nonlinearly with increasing fragment area. One important consequence of the synergy is that the slopes of species area (SA) curves constructed from habitat islands depend sensitively on the distance from edge at which sampling is conducted. Surprisingly, we found negative SA curves for communities sampled at intermediate distances from habitat edges, caused by differential edge responses of matrix- vs. forest-specialist species in fragments of increasing area. Our data indicate that distance to habitat edge has a consistently greater impact on beetle community composition than habitat area and that variation in the strength of edge effects may underlie many patterns that are superficially related to habitat area.

Reconciliation Ecology and Wetlands

Michael Rosenzweig has written one of the fundamental books of this decade (Rosenzweig 2003), and it has an important meaning for wetland scientists whose work addresses conservation topics. What Rosenzweig calls the “3rd R” is reconciliation ecology,2 his term for a view of human land use practices that blend those human uses with habitat elements that support species in the same landscapes. The premise underlying Rosenzweig’s approach is that the number of species that can exist in a given land area is a function of the area: smaller areas have fewer species and larger areas have more species, all other things being equal. This is called the “species–area (SA) relationship,” and it has occupied Rosenzweig throughout his professional career (see, for example, Rosenzweig 1995). In essence, the number of species, S, occurring in a given landscape area, A, is a power function of the general form:

Habitat loss and anthropogenic disturbance in Jamaica's Hellshire Hills area

This study provides empirical assessments of the magnitude of human pressures on forest habitat in Jamaica's Hellshire Hills. The Hellshire Hills represents an outstanding example of the Caribbean region's dry limestone forests. Approximately 160 km2 in area, the Hellshire Hills is home to a unique and rich biodiversity, including the critically endangered Jamaican Iguana (Cylcura collei). The area's biodiversity is under increasing threat from deforestation from subsistence driven encroachment. Using deforestation as a spatial indicator of habitat loss, the study derives satellite based estimates of the rate of habitat destruction within and immediately outside the area. The underlying human driving forces in this destruction are analyzed in a regression analysis of key socio-economic indicators that adusts for these locational differences. Results suggest that immiserating pressures on species habitat, particularly outside the area, are greater than anywhere else on the island. Simulations of species loss and edge-induced disturbances to species habitat also indicate that the potential impacts of forest conversion may be substantial and extend well beyond the area's boundaries. Together, the study's results highlight the intrinsic vulnerablity of the Hellshire Hills to outside disturbance. In particular, they raise doubts about the potential of the area (which has been accorded protected status within the recently established Portland Bight Protected Area) to provide for the long-term preservation and viability of the area's species. It is concluded that appropriate reserve design and species protection will require the collection of detailed empirical data on species diversity, numbers, habitat requirements, and spatial distribution. However, before this information can be collected priorities for biodiversity conservation must be set. Costs and benefits of conversation must also be assessed within the overall context of an integrated rural development plan for the area.

Anisotropic Shape of Islands and Species Richness of Land Snail Fauna of the Ryukyus.

We introduce a new immigration model in order to derive the famous power law on species-area (SA) relation for anisotropic island. This relation shows that the number of species is constrained not only by the size of the recipient island area or the species' dispersal capacity but also the power index of SA relation. Because this power index depends on island shapes, this means that island shape is one of the factor in constraining the number of species. From this viewpoint, we analyze an SA curve of the land snail fauna in forty-three islands in Ryukyu arc, Japan, and show that most individual species have travelled across the line of the island chain of the Ryukyu islands. Moreover, we reconsider the power index of SA relation in previous studies, and show that species have immigrated along the island chain by stepping-stone dispersal. We also consider the effect of the height of the surface topography on the species richness by using the Hurst parameter. Moreover, we point out that species richness and environmental heterogeneity have the same relationship with the area.

GEOMETRICAL EFFECT OF ISLAND SHAPE ON THE SPECIES RICHNESS

We introduce a new immigration model which merges two aspects of island length. One aspect is determination of colonizer's chance of reaching recipient island, and the other is constraint on the statistical self-affinity (anisotropy) of island shapes. This immigration model derives the famous power law on species-area (SA) relation, which shows that the number of species on the anisotropic island is constrained by not only the size of the island area but also the shape of the island. From this viewpoint, we analyze an SA curve of the land snail fauna in Ryukyu arc, Japan. Moreover, we show that species of the most previous studies have immigrated along the island chain due to the stepping-stone dispersal.