INFLUENCES OF RIPARIAN LAND-USES ON HABITAT USE AND INTERSPECIFIC COMPETITION OF STREAM-DWELLING SALAMANDERS: EVIDENCE FROM BLUE RIDGE & PIEDMONT

Human-induced disturbances can result in persistent influences on ecosystems, including habitat loss and biogeographical changes. Global amphibian decline, a consequence of habitat degradation, is among prime conservation concerns. To better understand causes of the amphibian crisis, investigations a multiple levels of biological organization - behavior, communities, and landscapes - is imperative. I investigated the responses of stream-associated Plethdontid salamanders of the Blue Ridge and Piedmont of the Southeastern US to historical and current land uses in the riparian zone and watershed to determine, (1) change in the community structure and mechanisms driving the change and uses operating at different spatial-temporal scales; (2) competition between two sympatric species with different body sizes, natural histories, and differential sensitivity for habitat alterations (black-bellied and northern dusky salamanders) in the context of riparian land uses. I surveyed low-order streams for salamanders, estimated 15 habitat variables and current and historical land-cover at riparian and watershed scale for each sampling site. Forested streams were more diverse than non-forested streams. Two assemblages were evident: disturbance avoiders (forest-dependent, large-bodied, disturbance-sensitive species) and disturbance tolerators (cosmopolitan, small-bodied, disturbance-resistant species); each assemblage composed of 80% and 20% of the regional species pool, respectively. Riparian zone characteristics (canopy cover, canopy height, leaf-litter cover) and stream geomorphology (bank complexity, stream substrate heterogeneity, sedimentation) were dramatically altered by land uses, rendering streams unsuitable for most salamanders. Historical land uses at both riparian- and watershed-scale influenced current populations and community structure of salamanders. Piedmont protected areas with crop-farming legacies were the most species-deprived since intensive agriculture can lead to lasting effects including soil erosion, sedimentation, increased discharge, and destabilization of stream banks. My experiment on competition revealed marked differences in microhabitat associations of focal species across riparian land uses. Black-bellied salamanders competitively dominated the use of stream channel over northern dusky salamanders in forested and agricultural streams. Northern dusky salamanders competitively displaced black-bellied salamanders from stream banks in urban streams. Riparian anthropogenic disturbances negatively affected the large-bodied habitat specialists and favored small-bodied habitat generalists. Terrestrial anthropogenic disturbances can modify stream habitats and, result in the exclusion of disturbance-sensitive species, ultimately leading to biotic homogenization. Conservation of stream salamander community should be strengthened with protection and restoration of riparian forests and degraded stream habitats; land-use regulations at the watershed scale; establishment of connectivity among riparian forests; and introduction of Best Management Practices for farmlands and timberlands

Impact of Vehicular Traffic on Vertebrate Fauna in Horton Plains and Yala National Parks of Sri Lanka: Some Implications for Conservation and Management

Abstract: Impacts of roadkills are extensively documented in developed nations. Only a handful of studies on road mortality has emerged from developing nations where tourism and rural development have led to an expansion of transportation networks. To fill such gaps, we conducted a survey to document roadkills in and around two tourism-heavy national parks of Sri Lanka and identified factors that contribute to road mortality. Based on a questionnaire, we interviewed 68 local villagers, 56 local and 59 foreign visitors, and 57 safari drivers to document their opportunistic observations on roadkills, their awareness about roadkills, and to understand potential causes of roadkills. We found 47 roadkilled vertebrate species at both parks; among these, 19 are threatened and 20 are endemic. Our research revealed that herpetofauna were killed the most. We concluded that increased visitation, high-speed driving, lack of awareness, and poor law enforcement as the likely causes of roadkills at both parks. As mitigatory actions, we proposed posting speed limits, increasing awareness of the tourists and safari drivers, limiting vehicle access to the parks, seasonal or night-time access restrictions, and strict enforcement of the speed limits inside national parks

Distribution, Natural History and the Conservation Status of Hemiphyllodactylus typus and Lepidodactylus lugubris (Reptilia: Gekkonidae) in Sri Lanka

Sri Lanka has a rich assemblage of gekkonid fauna. Among Sri Lankan geckos, rare species such as Hemiphyllodactylus typus and Lepidodactylus lugubris are poorly studied; both are considered vulnerable in national conservation assessments. Detailed ecological studies are needed for robust conservation assessments of these species, especially with the focus on island-wide distribution and microhabitat requirements. This study was conducted via patch sampling to record relative abundance and distribution of H. typus and L. lugubris based on random walks to 82 locations representing the three major bioclimatic zones of Sri Lanka. Morphological characteristics, behavior, and habitat use of the focal species were recorded. A total of 17 and 14 individuals of H. typus and L. lugubris were found, respectively, which indicated the low abundance of both species. Both species were nocturnal, arboreal, and did not den with conspecifics; they mostly preferred close-canopy, dense woody vegetation having mature moss-covered tree trunks with peeling barks and crevices over built-up environments. No records on oviposition were noted for either species. Both species were sluggish in their movements, even when disturbed. Currently known populations of both species occur in severely fragmented unprotected small forest patches. Therefore, habitat loss and fragmentation threaten these populations unless protected areas of Sri Lanka are expanded and functional connectivity is established

Forest ecosystem properties emerge from interactions of structure and disturbance

Forest structural diversity and its spatiotemporal variability are constrained by environmental and biological factors, including species pools, climate, land-use history, and legacies of disturbance regimes. These factors influence forest responses to disturbances and their interactions with structural diversity, potentially creating structurally mediated emergent properties at local to continental spatial scales and over evolutionary time. Here, we present a conceptual framework for exploring the emergent properties that arise from interactions between forest structural diversity and disturbances. We synthesize and present definitions for key terms, including emergent property, disturbance, and resilience, and highlight various types and examples of emergent properties, such as (1) interactions with species composition, (2) interactions with disturbance frequency and intensity, and (3) evolutionary changes to communities. Although emergent properties in forest ecosystems remain poorly understood, we describe a foundation for study and applied management of forest structural diversity to enhance forest restoration and resilience

Expanding NEON biodiversity surveys with new instrumentation and machine learning approaches

A core goal of the National Ecological Observatory Network (NEON) is to measure changes in biodiversity across the 30-yr horizon of the network. In contrast to NEON’s extensive use of automated instruments to collect environmental data, NEON’s biodiversity surveys are almost entirely conducted using traditional human-centric field methods. We believe that the combination of instrumentation for remote data collection and machine learning models to process such data represents an important opportunity for NEON to expand the scope, scale, and usability of its biodiversity data collection while potentially reducing long-term costs. In this manuscript, we first review the current status of instrument-based biodiversity surveys within the NEON project and previous research at the intersection of biodiversity, instrumentation, and machine learning at NEON sites. We then survey methods that have been developed at other locations but could potentially be employed at NEON sites in future. Finally, we expand on these ideas in five case studies that we believe suggest particularly fruitful future paths for automated biodiversity measurement at NEON sites: acoustic recorders for sound-producing taxa, camera traps for medium and large mammals, hydroacoustic and remote imagery for aquatic diversity, expanded remote and ground-based measurements for plant biodiversity, and laboratory-based imaging for physical specimens and samples in the NEON biorepository. Through its data science-literate staff and user community, NEON has a unique role to play in supporting the growth of such automated biodiversity survey methods, as well as demonstrating their ability to help answer key ecological questions that cannot be answered at the more limited spatiotemporal scales of human-driven surveys

Integrating forest structural diversity measurement into ecological research

The measurement of forest structure has evolved steadily due to advances in technology, methodology, and theory. Such advances have greatly increased our capacity to describe key forest structural elements and resulted in a range of measurement approaches from traditional analog tools such as measurement tapes to highly derived and computationally intensive methods such as advanced remote sensing tools (e.g., lidar, radar). This assortment of measurement approaches results in structural metrics unique to each method, with the caveat that metrics may be biased or constrained by the measurement approach taken. While forest structural diversity (FSD) metrics foster novel research opportunities, understanding how they are measured or derived, limitations of the measurement approach taken, as well as their biological interpretation is crucial for proper application. We review the measurement of forest structure and structural diversity—an umbrella term that includes quantification of the distribution of functional and biotic components of forests. We consider how and where these approaches can be used, the role of technology in measuring structure, how measurement impacts extend beyond research, and current limitations and potential opportunities for future research

A theoretical framework for the ecological role of three-dimensional structural diversity

The three-dimensional (3D) physical aspects of ecosystems are intrinsically linked to ecological processes. Here, we describe structural diversity as the volumetric capacity, physical arrangement, and identity/traits of biotic components in an ecosystem. Despite being recognized in earlier ecological studies, structural diversity has been largely overlooked due to an absence of not only a theoretical foundation but also effective measurement tools. We present a framework for conceptualizing structural diversity and suggest how to facilitate its broader incorporation into ecological theory and practice. We also discuss how the interplay of genetic and environmental factors underpin structural diversity, allowing for a potentially unique synthetic approach to explain ecosystem function. A practical approach is then proposed in which scientists can test the ecological role of structural diversity at biotic–environmental interfaces, along with examples of structural diversity research and future directions for integrating structural diversity into ecological theory and management across scales

Standardized NEON organismal data for biodiversity research

Understanding patterns and drivers of species distribution and abundance, and thus biodiversity, is a core goal of ecology. Despite advances in recent decades, research into these patterns and processes is currently limited by a lack of standardized, high-quality, empirical data that span large spatial scales and long time periods. The NEON fills this gap by providing freely available observational data that are generated during robust and consistent organismal sampling of several sentinel taxonomic groups within 81 sites distributed across the United States and will be collected for at least 30 years. The breadth and scope of these data provide a unique resource for advancing biodiversity research. To maximize the potential of this opportunity, however, it is critical that NEON data be maximally accessible and easily integrated into investigators\u27 workflows and analyses. To facilitate its use for biodiversity research and synthesis, we created a workflow to process and format NEON organismal data into the ecocomDP (ecological community data design pattern) format that were available through the ecocomDP R package; we then provided the standardized data as an R data package (neonDivData). We briefly summarize sampling designs and data wrangling decisions for the major taxonomic groups included in this effort. Our workflows are open-source so the biodiversity community may: add additional taxonomic groups; modify the workflow to produce datasets appropriate for their own analytical needs; and regularly update the data packages as more observations become available. Finally, we provide two simple examples of how the standardized data may be used for biodiversity research. By providing a standardized data package, we hope to enhance the utility of NEON organismal data in advancing biodiversity research and encourage the use of the harmonized ecocomDP data design pattern for community ecology data from other ecological observatory networks

Urbanisation generates multiple trait syndromes for terrestrial animal taxa worldwide

Cities can host significant biological diversity. Yet, urbanisation leads to the loss of habitats, species, and functional groups. Understanding how multiple taxa respond to urbanisation globally is essential to promote and conserve biodiversity in cities. Using a dataset encompassing six terrestrial faunal taxa (amphibians, bats, bees, birds, carabid beetles and reptiles) across 379 cities on 6 continents, we show that urbanisation produces taxon-specific changes in trait composition, with traits related to reproductive strategy showing the strongest response. Our findings suggest that urbanisation results in four trait syndromes (mobile generalists, site specialists, central place foragers, and mobile specialists), with resources associated with reproduction and diet likely driving patterns in traits associated with mobility and body size. Functional diversity measures showed varied responses, leading to shifts in trait space likely driven by critical resource distribution and abundance, and taxon-specific trait syndromes. Maximising opportunities to support taxa with different urban trait syndromes should be pivotal in conservation and management programmes within and among cities. This will reduce the likelihood of biotic homogenisation and helps ensure that urban environments have the capacity to respond to future challenges. These actions are critical to reframe the role of cities in global biodiversity loss.info:eu-repo/semantics/publishedVersio

Harnessing the NEON data revolution to advance open environmental science with a diverse and data-capable community

It is a critical time to reflect on the National Ecological Observatory Network (NEON) science to date as well as envision what research can be done right now with NEON (and other) data and what training is needed to enable a diverse user community. NEON became fully operational in May 2019 and has pivoted from planning and construction to operation and maintenance. In this overview, the history of and foundational thinking around NEON are discussed. A framework of open science is described with a discussion of how NEON can be situated as part of a larger data constellation—across existing networks and different suites of ecological measurements and sensors. Next, a synthesis of early NEON science, based on >100 existing publications, funded proposal efforts, and emergent science at the very first NEON Science Summit (hosted by Earth Lab at the University of Colorado Boulder in October 2019) is provided. Key questions that the ecology community will address with NEON data in the next 10 yr are outlined, from understanding drivers of biodiversity across spatial and temporal scales to defining complex feedback mechanisms in human–environmental systems. Last, the essential elements needed to engage and support a diverse and inclusive NEON user community are highlighted: training resources and tools that are openly available, funding for broad community engagement initiatives, and a mechanism to share and advertise those opportunities. NEON users require both the skills to work with NEON data and the ecological or environmental science domain knowledge to understand and interpret them. This paper synthesizes early directions in the community’s use of NEON data, and opportunities for the next 10 yr of NEON operations in emergent science themes, open science best practices, education and training, and community building