Modelling spatial patterns of biodiversity for conservation prioritization in North-eastern Mexico

Relationships between spatial patterns of bird and mammal species richness in north‐eastern Mexico were analysed in relation to the location of three biosphere reserves (El Abra‐Tanchipa, El Cielo, and Sierra Gorda) and 13 priority areas recently identified for conservation. Ecological niches were modelled and potential distributions delimited for 285 bird and 114 mammal species using a genetic algorithm based on locality information from museum specimens and 15 selected environmental attributes. Potential distributions were transformed into hypothesized current distributions based on species–habitat associations as reflected in a recent land‐use map. Although species richness was lower when distributions were reduced from potential to current, spatial patterns of potential and current richness were similar. Heuristic, complementarity‐based prioritization procedures were used to identify combinations of areas and sites with maximal species representation: the biosphere reserves included 79% of birds and 74% of mammal species; eight priority areas provided an additional 11% of birds and 13% of mammals; the remaining 10% of birds and 13% of mammals were concentrated in new sites across the study area.     

Mobilizing and integrating big data in studies of spatial and phylogenetic patterns of biodiversity

The current global challenges that threaten biodiversity are immense and rapidly growing. These biodiversity challenges demand approaches that meld bioinformatics, large-scale phylogeny reconstruction, use of digitized specimen data, and complex post-tree analyses (e.g. niche modeling, niche diversification, and other ecological analyses). Recent developments in phylogenetics coupled with emerging cyberinfrastructure and new data sources provide unparalleled opportunities for mobilizing and integrating massive amounts of biological data, driving the discovery of complex patterns and new hypotheses for further study. These developments are not trivial in that biodiversity data on the global scale now being collected and analyzed are inherently complex. The ongoing integration and maturation of biodiversity tools discussed here is transforming biodiversity science, enabling what we broadly term “next-generation” investigations in systematics, ecology, and evolution (i.e., “biodiversity science”). New training that integrates domain knowledge in biodiversity and data science skills is also needed to accelerate research in these areas. Integrative biodiversity science is crucial to the future of global biodiversity. We cannot simply react to continued threats to biodiversity, but via the use of an integrative, multifaceted, big data approach, researchers can now make biodiversity projections to provide crucial data not only for scientists, but also for the public, land managers, policy makers, urban planners, and agriculture.     

Fine-scale spatial and temporal distribution patterns of large marine predators in a biodiversity hotspot

Aim

Large marine predators, such as cetaceans and sharks, play a crucial role in maintaining biodiversity patterns and ecosystem function, yet few estimates of their spatial distribution exist. We aimed to determine the species richness of large marine predators and investigate their fine-scale spatiotemporal distribution patterns to inform conservation management.

Location

The Hauraki Gulf/Tīkapa Moana/Te Moananui-ā-Toi, Aotearoa/New Zealand.

Methods

We conducted a replicate systematic aerial survey over 12 months. Flexible machine learning models were used to explore relationships between large marine predator occurrence (Bryde's whales, common and bottlenose dolphins, bronze whaler, pelagic and immature hammerhead sharks) and environmental and biotic variables, and predict their monthly distribution and associated spatially explicit uncertainty.

Results

We revealed that temporally dynamic variables, such as prey distribution and sea surface temperature, were important for predicting the occurrence of the study species and species groups. While there was variation in temporal and spatial distribution, predicted richness peaked in summer and was the highest in coastal habitats during that time, providing insight into changes in distributions over time and between species.

Main Conclusions

Temporal changes in distribution are not routinely accounted for in species distribution studies. Our approach highlights the value of multispecies surveys and the importance of considering temporally variable abiotic and biotic drivers for understanding biodiversity patterns when informing ecosystem-scale conservation planning and dynamic ocean management.     

Structure and utilisation of the early oakwoods

Summary

The paper explores whether any of the familar range of current oakwood structures in the west of Scotland can be used as realistic analogues for the prehistoric oakwoods. Even for the early historic oak woodlands we have no detailed knowledge of previous structures and composition.

The structure of today's oak woodlands, and to some extent even the legacy of species within that habitat, are a type of biocultural heritage. The oak woodlands that we see today are the product of a long interaction: between man's use of the woodlands and the ongoing natural processes within the oakwood ecosystem.

Grazing animals, especially domestic cattle and red deer, have played a key part in determining oak woodland structure in historic times, and perhaps have a future role too. Are there lessons to be drawn from knowledge of past management and regeneration of oak which are relevant to the present day, when most managers are finding it difficult to regenerate oak woodlands on any scale?

Understanding past utilisation and structure of oak woodlands is valuable mainly as a guide to future management. Indeed one might ask which models and structures are relevant for managing an oak woodland resource now regarded mainly as a wildlife habitat?     

Latitudinal patterns of forest ecosystem stability across spatial scales as affected by biodiversity and environmental heterogeneity

Our planet is facing a variety of serious threats from climate change that are unfolding unevenly across the globe. Uncovering the spatial patterns of ecosystem stability is important for predicting the responses of ecological processes and biodiversity patterns to climate change. However, the understanding of the latitudinal pattern of ecosystem stability across scales and of the underlying ecological drivers is still very limited. Accordingly, this study examines the latitudinal patterns of ecosystem stability at the local and regional spatial scale using a natural assembly of forest metacommunities that are distributed over a large temperate forest region, considering a range of potential environmental drivers. We found that the stability of regional communities (regional stability) and asynchronous dynamics among local communities (spatial asynchrony) both decreased with increasing latitude, whereas the stability of local communities (local stability) did not. We tested a series of hypotheses that potentially drive the spatial patterns of ecosystem stability, and found that although the ecological drivers of biodiversity, climatic history, resource conditions, climatic stability, and environmental heterogeneity varied with latitude, latitudinal patterns of ecosystem stability at multiple scales were affected by biodiversity and environmental heterogeneity. In particular, α diversity is positively associated with local stability, while β diversity is positively associated with spatial asynchrony, although both relationships are weak. Our study provides the first evidence that latitudinal patterns of the temporal stability of naturally assembled forest metacommunities across scales are driven by biodiversity and environmental heterogeneity. Our findings suggest that the preservation of plant biodiversity within and between forest communities and the maintenance of heterogeneous landscapes can be crucial to buffer forest ecosystems at higher latitudes from the faster and more intense negative impacts of climate change in the future.     

Using modelled stream temperatures to predict macro‐spatial patterns of stream invertebrate biodiversity

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Ophiuroid biodiversity patterns along the Antarctic Peninsula

Benthic ecological surveys using standardized methods are crucial for assessing changes associated with several threats in the Southern Ocean. The acquisition of data on assemblage structure over a variety of spatial scales is important to understand the variation of biodiversity patterns. During the ANT XXIX/3 (PS81) expedition of RV Polarstern, three different regions at the tip of the Antarctic Peninsula were sampled: the northwestern Weddell Sea, the Bransfield Strait, and the northern boundary of the South Shetland Archipelago in the Drake Passage. The aim of this study was to characterize the distribution and biodiversity patterns of ophiuroid assemblages in these regions and depths. We quantified different community parameters in terms of the number of species, abundance, and biomass. Additionally, we calculated various components of species diversity (alpha, beta, and gamma diversity) over the three regions. Based on the benthic surveys, we collected 3331 individuals that were identified to species level (17 species). Overall, species diversity, as measured based on rarefaction, species richness and evenness estimators, was higher in the Bransfield Strait compared to the Weddell Sea and Drake Passage. Two deep stations in the Weddell Sea showed high dominance only of Ophionotus victoriae. Significant differences in the patterns of alpha diversity were found among the regions but not between depth zones, whereas beta diversity showed no differences. Regarding the resemblance among the ophiuroid assemblages of each region, there was a significant gradient from east to west with a maximum distance between the stations in the Drake Passage and the Weddell Sea. This study provides a baseline for detecting potential effects related to climate change, and it furnishes a basis for the implementation of monitoring schemes of Antarctic assemblages.     

Global patterns in peatmoss biodiversity

DNA sequence data from the nuclear ribosomal internal transcribed spacers (ITS) and the trnL-trnF chloroplast DNA regions were used to quantify geographical partitioning of global biodiversity in peatmosses (Sphagnum), and to compare patterns of molecular diversity with patterns of species richness. Molecular diversity was estimated for boreal, tropical, Neotropical, nonboreal (tropical plus Southern Hemisphere), Old World and New World partitions, based on a total of 436 accessions. Diversity was partitioned among geographical regions in terms of combined nuclear and chloroplast sequence data and separately for the ITS and trnL-trnF data sets. Levels of variation were estimated using phylogenetic diversity (PD), which incorporates branch lengths from a phylogenetic tree, and the number of polymorphic nucleotide sites. Estimates of species richness suggest that peatmoss diversity is higher in New World than Old World regions, and that the Neotropics constitute a "hotspot" of diversity. Molecular estimates, in contrast, indicate that peatmoss biodiversity is almost evenly divided between New and Old World regions, and that the Neotropics account for only 20-35% of global peatmoss diversity. In general, levels of tropical and boreal peatmoss molecular diversity were comparable. Two species, S. sericeum from the Old World tropics and S. lapazense from Bolivia, are remarkably divergent in nucleotide sequences from all other Sphagna and together account for almost 20% of all peatmoss diversity, although they are represented by only three of the 436 accessions (0.7%). These species clearly demonstrate the nonequivalence of species biodiversity value.     

Large-scale spatial synchrony and the stability of forest biodiversity revisited

Aims Mechanisms contributing to species coexistence have at least one of two modes of action: (i) stabilization of populations through restoring forces and (ii) equalization of fitness across individuals of different species. Recently, ecologists have begun gleaning the relative roles of these by testing the predictions of neutral theory, which predicts the properties of communities under pure fitness equalization. This null hypothesis was rejected for forests of southern Ontario based on large-scale (~100 km) spatial synchrony evident in the fossil pollen record over the entire Holocene, and the argument that a species' relative abundance would instead vary independently at such distances in the absence of stabilizing mechanisms. This test of neutral theory was criticized based on the idea that the synchrony might be produced by dispersal alone. Here, I revisit this test of neutral theory by explicitly calculating the synchrony expected in these forests using a novel simulation method enabling examination of the distribution of a species over large spatial and temporal scales.Methods A novel neutral simulation algorithm tracking only the focal species was used to calculate the neutral expectation for spatial synchrony properties examined empirically by Clark and MacLachlan [(2003) Stability of forest biodiversity. Nature 423 :635–8] using fossil pollen data from eight lake sites. The coefficient of variation (CV) in a species' relative abundance across the eight sites (initiated at about 10% with a small CV) was calculated for 10 runs over a 10?000 year time interval. The CV reflects the level of spatial synchrony in that less synchronous dynamics should lead to more variation across space (a higher equilibrium CV), and in particular, a greater increase in the CV over time from a small initial value. A 'two dimensional t' fat-tailed dispersal kernel was assumed with parameters set to the median derived from seed trap data for deciduous wind-dispersed trees. Robustness of results to assumed dispersal distance, density of trees on the landscape, site sizes, age at maturity and starting spatial distribution were checked.Important findings In contrast to the prediction of Clark and MacLachlan that, in the absence of stabilization, the CV across the sites should increase over time from levels observed at the beginning of the Holocene, under fat-tailed dispersal my neutral model robustly predicted only a brief (50 years) and small increase in the CV. I conclude that purely fitness-equalized species coexistence cannot be rejected based on the observed lack of increase in the CV across the eight sites in southern Ontario over the Holocene. Synchronous variation in environmental factors could alternatively explain the observed synchrony without the need for stabilization. However, neither dispersal nor environmental synchrony seems likely explanations for the quick widespread recovery of Tsuga in the Holocene after its seeming decimation, likely due to a pest outbreak.     

Exploring spatial indicators for biodiversity accounting

In the context of the System for Environmental-Economic Accounting, biodiversity accounting is being developed as a tool to monitor and increase the understanding of human impacts on biodiversity. Biodiversity accounting aims to structurally measure, monitor and map changes in multiple biodiversity components, as an integral part of a larger system of ecosystem accounts. Both indicators relevant for ecosystem functioning and indicators that reflect the non-use values of biodiversity can be included in biodiversity accounting. In this paper we focus on the latter, and we test the potential applicability of a set of species indicators for developing a biodiversity account in Limburg province, the Netherlands. In particular, we map and analyse a range of indicators reflecting species richness, the presence of rare and threatened species and species diversity. We test spatial correlation to identify the minimum set of indicators that would need to be included in the account. We also evaluate individual indicators using eight different criteria. We show that, in Limburg province, a set of indicators covering at least five species groups is required, and that it would be most meaningful to have indicators reflecting the occurrence of threatened species. However, data availability as well as the most suitable set of indicators are likely to differ between areas, and case studies in other countries are required to support the selection of indicators for biodiversity accounting in an international framework.     

Conservation of endangered species and the patterns and propensities of biodiversity

It is commonly asserted in the ecological and economic literature that habitat loss is the main cause of loss of imperiled species. The evidence clearly shows that habitat loss is a common contributing factor, but there is little evidence that it is the most important factor. Studies that have focused on the mechanisms of species loss have failed to produce models capable of predicting patterns of loss as a function of human activities. I propose that this is because ecologists have employed an unrealistic conceptual model of the functioning of natural systems. Karl Popper's construct of the propensities of natural systems provides a more realistic view, and better potential to yield predictive models. I provide two examples of patterns of biodiversity and species loss in Canada where mechanistic reasoning is inconsistent with the observed propensities of species loss.     

The role of climate,water and biotic interactions in shaping biodiversity patterns in arid environments across spatial scales

Aim

Desert ecosystems, with their harsh environmental conditions, hold the key to understanding the responses of biodiversity to climate change. As desert community structure is influenced by processes acting at different spatial scales, studies combining multiple scales are essential for understanding the conservation requirements of desert biota. We investigated the role of environmental variables and biotic interactions in shaping broad and fine‐scale patterns of diversity and distribution of bats in arid environments to understand how the expansion of nondesert species can affect the long‐term conservation of desert biodiversity.

Location

Levant, Eastern Mediterranean.

Methods

We combine species distribution modelling and niche overlap statistics with a statistical model selection approach to integrate interspecific interactions into broadscale distribution models and fine‐scale analysis of ecological requirements. We focus on competition between desert bats and mesic species that recently expanded their distribution into arid environment following anthropogenic land‐use changes.

Results

We show that both climate and water availability limit bat distributions and diversity across spatial scales. The broadscale distribution of bats was determined by proximity to water and high temperatures, although the latter did not affect the distribution of mesic species. At the fine‐scale, high levels of bat activity and diversity were associated with increased water availability and warmer periods. Desert species were strongly associated with warmer and drier desert types. Range and niche overlap were high among potential competitors, but coexistence was facilitated through fine‐scale spatial partitioning of water resources.

Main conclusions

Adaptations to drier and warmer conditions allow desert‐obligate species to prevail in more arid environments. However, this competitive advantage may disappear as anthropogenic activities encroach further into desert habitats. We conclude that reduced water availability in arid environments under future climate change projections pose a major threat to desert wildlife because it can affect survival and reproductive success and may increase competition over remaining water resources.     

The fungi of Scottish Western oakwoods

Summary

Unfortunately the Atlantic oakwoods of Scotland have never been targeted by mycologists and information is very patchy. The best data lie in the lists of fungi from the Inner Hebridean oakwoods and it is on these records which go back to the end of the 19th century, and limited information from the mainland that a potential picture is offered. There appear to be no fungi specific to Western oakwoods and there are few differences between eastern and western oak communities in Scotland. Emphasis is placed on the need for more funding for those who can identify and recognise potential indicator species so that progress can be made.     

Vertical stratification influences global patterns of biodiversity

Species distributions in terrestrial ecosystems are three‐dimensional, spanning both the horizontal landscape and the vertical space provided by the physical environment. Classical hypotheses suggest that communities become more vertically stratified with increasing species richness, owing to reduced competition or finer niche subdivision. However, this assertion remains untested in the context of the broader realm of biogeography. Here, integrating traits and distribution data for amphibians globally, we show how vertical strategies interact with the physical and climatic environments to govern global patterns of species richness and community composition. Our results reveal a marked latitudinal shift in strategies of vertical habitat use, from highly arboreal assemblages in the tropics to highly fossorial assemblages in sub‐tropical and temperate regions. Arboreality is strongly associated with precipitation, vegetation structure and climatic stability, whereas fossoriality is more common in dry environments with high diurnal temperature range and low vegetation structure. These analyses shed light on the importance of vertical stratification for species coexistence in species‐rich regions. As certain tropical habitats become drier from climate change, the rich biological diversity that is emblematic of the tropics may transition from vertically stratified to ‘flattened’, with future communities living mostly on or beneath the ground.     

Historical and contemporary factors govern global biodiversity patterns

A novel hierarchical framework integrates the effects of time, area, productivity, and temperature at their respective relevant scales and successfully predicts the latitudinal gradient in global vertebrate diversity.     

Current and future patterns of global marine mammal biodiversity

Quantifying the spatial distribution of taxa is an important prerequisite for the preservation of biodiversity, and can provide a baseline against which to measure the impacts of climate change. Here we analyse patterns of marine mammal species richness based on predictions of global distributional ranges for 115 species, including all extant pinnipeds and cetaceans. We used an environmental suitability model specifically designed to address the paucity of distributional data for many marine mammal species. We generated richness patterns by overlaying predicted distributions for all species; these were then validated against sightings data from dedicated long-term surveys in the Eastern Tropical Pacific, the Northeast Atlantic and the Southern Ocean. Model outputs correlated well with empirically observed patterns of biodiversity in all three survey regions. Marine mammal richness was predicted to be highest in temperate waters of both hemispheres with distinct hotspots around New Zealand, Japan, Baja California, the Galapagos Islands, the Southeast Pacific, and the Southern Ocean. We then applied our model to explore potential changes in biodiversity under future perturbations of environmental conditions. Forward projections of biodiversity using an intermediate Intergovernmental Panel for Climate Change (IPCC) temperature scenario predicted that projected ocean warming and changes in sea ice cover until 2050 may have moderate effects on the spatial patterns of marine mammal richness. Increases in cetacean richness were predicted above 40° latitude in both hemispheres, while decreases in both pinniped and cetacean richness were expected at lower latitudes. Our results show how species distribution models can be applied to explore broad patterns of marine biodiversity worldwide for taxa for which limited distributional data are available.     

Disturbances, elevation, topography and spatial proximity drive vegetation patterns along an altitudinal gradient of a top biodiversity hotspot

The correlation between vegetation patterns (species distribution and richness) and altitudinal variation has been widely reported for tropical forests, thereby providing theoretical basis for biodiversity conservation. However, this relationship may have been oversimplified, as many other factors may influence vegetation patterns, such as disturbances, topography and geographic distance. Considering these other factors, our primary question was: is there a vegetation pattern associated with substantial altitudinal variation (10–1,093 m a.s.l.) in the Atlantic Rainforest—a top hotspot for biodiversity conservation—and, if so, what are the main factors driving this pattern? We addressed this question by sampling 11 1-ha plots, applying multivariate methods, correlations and variance partitioning. The Restinga (forest on sandbanks along the coastal plains of Brazil) and a lowland area that was selectively logged 40 years ago were floristically isolated from the other plots. The maximum species richness (>200 spp. per hectare) occurred at approximately 350 m a.s.l. (submontane forest). Gaps, multiple stemmed trees, average elevation and the standard deviation of the slope significantly affected the vegetation pattern. Spatial proximity also influenced the vegetation pattern as a structuring environmental variable or via dispersal constraints. Our results clarify, for the first time, the key variables that drive species distribution and richness across a large altitudinal range within the Atlantic Rainforest.