Integrating functional connectivity and fire management for better conservation outcomes

Globally, the mean abundance of terrestrial animals has fallen by 50% since 1970, and populations face ongoing threats associated with habitat loss, fragmentation, climate change, and disturbance. Climate change can influence the quality of remaining habitat directly and indirectly by precipitating increases in the extent, frequency, and severity of natural disturbances, such as fire. Species face the combined threats of habitat clearance, changing climates, and altered disturbance regimes, each of which may interact and have cascading impacts on animal populations. Typically, conservation agencies are limited in their capacity to mitigate rates of habitat clearance, habitat fragmentation, or climate change, yet fire management is increasingly used worldwide to reduce wildfire risk and achieve conservation outcomes. A popular approach to ecological fire management involves the creation of fire mosaics to promote animal diversity. However, this strategy has 2 fundamental limitations: the effect of fire on animal movement within or among habitat patches is not considered and the implications of the current fire regime for long-term population persistence are overlooked. Spatial and temporal patterns in fire history can influence animal movement, which is essential to the survival of individual animals, maintenance of genetic diversity, and persistence of populations, species, and ecosystems. We argue that there is rich potential for fire managers to manipulate animal movement patterns; enhance functional connectivity, gene flow, and genetic diversity; and increase the capacity of populations to persist under shifting environmental conditions. Recent methodological advances, such as spatiotemporal connectivity modeling, spatially explicit individual-based simulation, and fire-regime modeling can be integrated to achieve better outcomes for biodiversity in human-modified, fire-prone landscapes. Article impact statement: Land managers may conserve populations by using fire to sustain or enhance functional connectivity

Mammal responses to spatial pattern in fire history depend on landscape context

Context: Interactions between multiple threats are driving biodiversity loss. In human-modified landscapes, the extent to which fire regimes threaten species may depend on the configuration of native vegetation in relation to the matrix of other land uses. Despite crucial implications for fire management, interactions between spatial pattern in fire history and the matrix are unstudied. Objectives: We used a multi-scale analysis to address two questions: do mammals respond to the landscape-context effect of the extent of older vegetation or growth-stage diversity? If so, are responses influenced by the presence of matrix? Methods: Camera traps were used to survey mammals in the fragmented heathy woodland of southeast Australia. We quantified the percent of older vegetation, growth-stage diversity and matrix presence using 16 concentric circles centred on sites, and examined species’ responses using generalised linear models. Results: We modelled eight species and found the responses of five species to fire history were influenced by matrix availability. Four species (three macropods and the yellow-footed antechinus, Antechinus flavipes) responded positively to growth-stage diversity when matrix was absent and vice versa, indicating that species acquire different resources from multiple growth stages in the absence of matrix. Moreover, these results suggest that using prescribed fire to create a mosaic of growth stages at scales of 80–710 ha may have positive conservation outcomes for these species. Conclusions: Our study highlights the importance of examining the consequences of interacting threats. Consideration of landscape context in fire management may lead to better conservation outcomes for mammals in human-modified landscapes

Hole-burning and zero-field ODMR of quasi-linear chain excitons in 1,4-dibromonaphthalene

Observations of hole-burning and zero-field ODMR spectra of the quasi-one-dimensional 1,4-dibromonaphthalene solid are reported. Dephasing rates, spin—lattice relaxation and dispersion in ODMR frequencies are used to propose a model for the dynamics: pure dephasing of k states versus thermalization

Hole-burning and zero-field ODMR of quasi-linear chain excitons in 1,4-dibromonaphthalene

Observations of hole-burning and zero-field ODMR spectra of the quasi-one-dimensional 1,4-dibromonaphthalene solid are reported. Dephasing rates, spin—lattice relaxation and dispersion in ODMR frequencies are used to propose a model for the dynamics: pure dephasing of k states versus thermalization

Exploring the attitudes and knowledge of first-year students at CPUT with regard to termination of pregnancy

32nd Conference of the Southern African Association for Counselling and Development in Higher Education (SAACDHE

Opposing Responses of Bird Functional Diversity to Vegetation Structural Diversity in Wet and Dry Forest

Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD) provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion) were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion) were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated with vegetation diversity in wet forest, but positively correlated with vegetation diversity in dry forest. We therefore suggest that protection of older vegetation is important, but controlled application of low-severity fire in dry forest may sustain ecosystem function by enhancing different elements of FD

Ground-dwelling mammal diversity responds positively to productivity and habitat heterogeneity in a fire-prone region

Environmental heterogeneity has a consistent, positive effect on species diversity globally, principally due to increased niche space in heterogeneous environments. In flammable ecosystems, fire‐mediated heterogeneity (pyrodiversity) is expected to increase species diversity, and the application of diverse fire regimes is a common management goal. We used landscape‐scale sampling units and linear mixed models to determine the response of ground‐dwelling mammal alpha, beta, and gamma diversity to spatial habitat heterogeneity (functional heterogeneity) and three indirect measures of spatial heterogeneity, two pyrodiversity indices based on fire history maps, and another based on mapped vegetation types. In addition, we tested the consistency of species diversity responses across a productivity gradient and examined the extent to which prescribed fire influenced habitat heterogeneity. Beta diversity responded positively to habitat heterogeneity across the productivity gradient, but more strongly at high compared with low productivity. In contrast, alpha and gamma diversity responded positively to productivity, while a weak negative effect of habitat heterogeneity on alpha diversity was also evident. At the scale of our investigation, the productivity gradient across the study area was the most influential driver of species diversity. Spatial heterogeneity within 100‐ha landscapes increased community differentiation among sites (beta diversity), had a weak negative effect on alpha diversity, but had no influence on landscape‐scale species richness (gamma diversity). The occurrence of recent fire had a strong, positive effect on habitat heterogeneity, while the diversity of vegetation types and postfire age classes had a smaller positive influence. Our findings show that prescribed fire can be used to increase landscape‐scale structural heterogeneity, but this will not always result in additional species. Finally, we suggest that using a functional representation of spatial heterogeneity (e.g., the spatial arrangement of habitat structure) as a predictor of species diversity is likely to reveal responses that may otherwise be overlooked. Modern remote‐sensing technologies will aid the development of habitat‐based heterogeneity metrics across large spatial extents