Treesearch

The California spotted owl (Strix occidentalis occidentalis), an older forest species of conservation concern, has declined in many historically occupied forests due to habitat loss from severe wildfire and other environmental changes. Although population trends have been well documented in the Sierra Nevada mountain range in the western United States, less is known about population status at the range boundary in Southern California, a region experiencing rapid environmental change. Therefore, we conducted extensive spotted owl nighttime surveys during the 2022 breeding season in the San...

Protected areas form the backbone of modern conservation. However, the current policies and practices in protected areas reinforce a static view of nature. This view is further enabled by cultural resistance to change, including efforts to mitigate or exclude keystone ecosystem processes (e.g., characteristic wildfire) that that create and maintain desired conditions. This protectionist model of conservation undervalues the human role in generating landscape dynamics and will be ineffective over the long term and increasingly in the short term. Under climatic change, resisting natural...

Does environmental DNA (eDNA) concentration correlate with numerical abundance (N) or biomass in aquatic organisms? We hypothesize that eDNA can be adjusted to simultaneously reflect both. Building on frameworks developed from the Metabolic Theory of Ecology, we derive two equations to adjust eDNA data to simultaneously reflect both N and biomass using population size structure data and allometric scaling coefficients. We also demonstrate that these equations share model parameters, necessitating the joint estimation of regressions between adjusted eDNA, N, and biomass. Furthermore, our...

Prey species adjust their behavior along human-use gradients by balancing risks from predators and humans. During hunting seasons, prey often exhibit strong antipredator responses to humans but may develop tolerance in suburban areas to exploit human-mediated resources. Additionally, areas with high human activity may offer reduced predation risk if apex predators avoid such locations. This study examined mule deer Odocoileus hemionus behavioral responses to risks from humans and their primary predators, cougars Puma concolor, contextualized by differences in risk levels between study...

In many forests globally, resilience-focused restoration is necessary to prevent fire-driven regime shifts. However, restoration planning is challenged by limited resources for monitoring biodiversity responses to management intervention and to natural disturbances. Bioregional-scale passive acoustic monitoring, when combined with automated species identification tools and management-relevant habitat data, can be a tractable method to simultaneously monitor suites of complementary indicator species and rapidly generate species-specific information for resource managers. We demonstrate...

Changing climate and its interaction with disturbances is reshaping forests of the western United States and southwestern forests are experiencing these changes at an accelerated pace. Southwestern forests are fire prone and a legacy of fire exclusion from past land use and management have homogenized many frequent fire forests, increasing the chance that disturbances reinforce landscape homogeneity. Widespread disturbances, especially those that cause a vegetation type change from forest to non-forest, are and will continue to influence the provision of ecosystem services upon which...

and anthropogenic climate change have led to larger, more severe fires that threaten many animal species where such disturbances do not occur naturally. As predators, owls can play important ecological roles in biological communities, but how changing fire regimes affect individual species and species assemblages is largely unknown. Here, we examined the impact of fire severity, history, and configuration over the past 35 years on an assemblage of six forest owl species in the Sierra Nevada, California, using ecosystem-scale passive acoustic monitoring. While the negative impacts of fire...

Accurate, cost-effective monitoring remains a major limitation to conservation efforts for many wildlife species. The USA federally threatened eastern indigo snake (Drymarchon couperi) exemplifies this sampling challenge. They occur at low densities, are cryptic, and highly mobile, which has historically made them challenging and expensive to monitor. However, emerging technologies and methodologies may provide new pathways to augment, complement, or replace conventional sampling to yield improved monitoring programs, both for eastern indigo snakes and for other imperiled and cryptic taxa....

The increasing severity and frequency of droughts will play a pivotal role in shaping future forest ecosystems worldwide. Trees growing in mixtures are thought to be less susceptible to drought stress, but evidence for such positive admixture effects remains limited. This study examines how interspecific neighbourhood structures affect the growth responses of pine and oak species under recurrent drought stress in two contrasting forest ecosystems.We sampled naturally occurring, unmanaged mixed stands of Gambel oak (Quercus gambelii) and ponderosa pine (Pinus ponderosa) in semi-arid...

Pyrotown is a serious game developed as an educational tool for the Master-level course 'Integrated Fire Management' at Wageningen University & Research (WUR). It is a role-playing game (or social simulation) designed to support social learning amongst Master students regarding the challenges that face multi-stakeholder groups and communities that attempt to create an integrated fire management strategy in a complex and changing world. It includes two surprise crisis events that interrupt the game in real time to add new elements and heighten the urgency for decision-making. After playing...