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Abstract Interspecific competition, environmental filtering, or spatial variation in productivity can contribute to positive or negative spatial covariance in the abundances of species across ensembles (i.e., groups of interacting species defined by geography, resource use, and taxonomy). In contrast, density compensation should give rise to a negative relationship between ecomorphological similarity and abundance of species within ensembles. We evaluated (1) whether positive or negative covariances characterized the pairwise relationships of 21 species of Congolese shrew, and (2) whether density compensation characterized the structure of each of 36 Congolese shrew ensembles, and did so based on the abundances or biomasses of species. In general, positive covariance is more common than negative covariance based on considerations of abundance or biomass, suggesting dominant roles for environmental filtering and productivity. Nonetheless, negative covariance is more common for ecomorphologically similar species, suggesting a dominant role for competition within functional groups. Effects of abundance or biomass compensation, via pairwise or diffuse competitive interactions, were detected less often than expected by chance, suggesting that interspecific competition is not the dominant mechanism structuring these ensembles. Effects of competition may be balanced by responses to variation in resource abundance among sites in a landscape or among niche spaces within sites. Future studies of compensatory effects should incorporate considerations of heterogeneity in the abundance and distribution of resources in ecological space to better isolate the effects of competition and resource abundance, which can have opposing effects on community structure. 

Abstract Quantification of phenological patterns (e.g. migration, hibernation or reproduction) should involve statistical assessments of non‐uniform temporal patterns. Circular statistics (e.g. Rayleigh test or Hermans‐Rasson test) provide useful approaches for doing so based on the number of individuals that exhibit particular activities during a number of time intervals.This study used monthly reproductive activity as an example to illustrate problems in applying circular statistics to data when marginal totals characterize experimental designs (e.g. the number of reproductively active individuals per time interval depends on sampling effort or sampling success). We illustrate the nature of this problem by crafting four exemplar data sets and developing a bootstrapping simulation procedure to overcome complications that arise from the existence of marginal totals. In addition, we apply circular statistics and our bootstrapping simulation to empirical data on the reproductive phenology of six species of Neotropical bats from the Amazon.Because sampling effort or success can differ among time intervals, circular statistics can produce misleading results of two types: those suggesting uniform phenologies when empirical patterns are markedly modal, and those suggesting non‐uniform phenologies when empirical patterns are uniform. The bootstrapping simulation overcomes these limitations: the exemplar phenology in which the percentage of reproductively active individuals is modal is appropriately identified as non‐uniform based on the bootstrapping approach, and the exemplar phenology in which the percentage of reproductively active individuals is invariant is appropriately identified as uniform based on the bootstrapping approach. The reproductive phenology of each of the six empirical examples is non‐uniform based on the bootstrapping approach, and this is true for bats species with unimodal peaks or bimodal peaks.In addition to problems with marginal totals, a review of analyses of phenological patterns in ecology identified two other frequent issues in the application of circular statistics: sampling bias and pseudoreplication. Each of these issues and potential solutions are also discussed. By providing source code for the execution of the Rayleigh test and Hermans‐Rasson test, along with the code for the bootstrapping simulation, we offer a useful tool for assessing non‐random phenologies when marginal totals characterize experimental designs. 

Abstract The equilibrium theory of island biogeography and its quantitative consideration of origination and extinction dynamics as they relate to island area and distance from source populations have evolved over time and enriched theory related to many disciplines in spatial ecology. Indeed, the island focus was catalytic to the emergence of landscape ecology and macroecology in the late 20th century. We integrate concepts and perspectives of island biogeography, landscape ecology, macroecology, and metacommunity ecology, and show how these disciplines have advanced the understanding of variation in abundance, biodiversity, and composition of bat communities. We leverage the well‐studied bat fauna of the islands in the Caribbean to illustrate the complex interplay of ecological, biogeographical, and evolutionary processes in molding local biodiversity and system‐wide structure. Thereafter, we highlight the role of habitat loss and fragmentation, which is increasing at an accelerating rate during the Anthropocene, on the structure of local bat communities and regional metacommunities across landscapes. Bat species richness increases with the amount of available habitat, often forming nested subsets along gradients of patch or island area. Similarly, the distance to and identity of sources of colonization influence the richness, composition, and metacommunity structure of islands and landscape networks. 

The Anthropocene is characterized by complex, primarily human‐generated, disturbance regimes that include combinations of long‐term press (e.g. climate change, pollution) and episodic pulse (e.g. cyclonic storms, floods, wildfires, land use change) disturbances. Within any regime, disturbances occur at multiple spatial and temporal scales, creating complex and varied interactions that influence spatiotemporal dynamics in the abundance, distribution and biodiversity of organisms. Moreover, responses to disturbance are context dependent, with the legacies of previous disturbances affecting responses to ensuing perturbations. We use three decades of annual data to evaluate the effects of repeated pulse disturbances and global warming on gastropod populations and communities in Puerto Rico at multiple spatial scales. More specifically, we quantify 1) the relative importance of large‐scale and small‐scale aspects of disturbance on variation in abundance, biodiversity and species composition; and 2) the spatial scales at which populations and communities integrate information in the spatially heterogenous environments created by disturbances. Gastropods do not exhibit consistent decreases in abundance or biodiversity in association with global warming: abundance for many species has increased over time and species richness does not evince a temporal trend. Nonetheless, gastropods are sensitive to hurricane severity, spatial environmental variation and successional trajectories of the flora. In addition, they exhibit context dependent (i.e. legacy effects) responses that are scale dependent. The Puerto Rican biota has evolved in a disturbance‐mediated system. This historical exposure to repeated, severe hurricane‐induced disturbances has imbued the biota with high resistance and resilience to the current disturbance regime, resulting in an ability to persist or thrive under current environmental conditions. Nonetheless, these ecosystems may yet be threatened by worsening direct and indirect effects of climate change. In particular, more frequent and severe hurricanes may prevent the establishment of closed canopy forests, negatively impacting populations and communities that rely on these habitats. 

A key element of conservation action involves the incorporation of sites into networks of protected areas. Historically, most network-creation strategies have been based on considerations of species richness and site complementarity. Nonetheless, phylogenetic or functional biodiversity may be more critical to the maintenance of ecosystem resilience or functioning than is the number of species. Therefore, we explore the efficacy of three strategies (i.e., random, sequential, and simultaneous inclusion of sites into conservation networks of particular sizes) to maximize species richness in a network, and explore associated consequences to aspects of functional and phylogenetic biodiversity. We do so for passerines in Connecticut, bats in Paraguay, and trees in North Carolina, which differ in β, functional, and phylogenetic biodiversity. The efficacy of sequential and simultaneous strategies for conserving species richness are similar at all network sizes and represent improvements over random strategies for each of the three taxa, conserving all species in as few as 35 % of the sites required based on a random strategy. For aspects of functional and phylogenetic biodiversity, metrics converged on the value of the entire biota, even when networks contained as few as five sites, suggesting that richness-based approaches can be effective in guiding conservation action from multiple perspectives. Evaluation of networks intended to conserve biodiversity at spatial extents that include more complex environmental gradients than the examples presented here, or that comprise more heterogenous environments than those represented in our analyses, are needed to more fully explore the generality of our conclusions. 

In addition to changes associated with climate and land use, parrots are threatened by hunting and capture for the pet trade, making them one of the most at risk orders of birds for which conservation action is especially important. Species richness is often used to identify high priority areas for conserving biodiversity. By definition, richness considers all species to be equally different from one another. However, ongoing research emphasizes the importance of incorporating ecological functions (functional diversity) or evolutionary relationships (phylogenetic diversity) to more fully understand patterns of biodiversity, because (1) areas of high species richness do not always represent areas of high functional or phylogenetic diversity, and (2) functional or phylogenetic diversity may better predict ecosystem function and evolutionary potential, which are essential for effective long–term conservation policy and management. We created a framework for identifying areas of high species richness, functional diversity, and phylogenetic diversity within the global distribution of parrots. We combined species richness, functional diversity, and phylogenetic diversity into an Integrated Biodiversity Index (IBI) to identify global biodiversity hotspots for parrots. We found important spatial mismatches between dimensions, demonstrating species richness is not always an effective proxy for other dimensions of parrot biodiversity. The IBI is an integrative and flexible index that can incorporate multiple dimensions of biodiversity, resulting in an intuitive and direct way of assessing comprehensive goals in conservation planning.