Treesearch

The long-term supply of ecosystem services is dependent on properly functioning ecosystems and their susceptibility to natural and anthropogenic disturbances such as climate change and urbanization, as they can alter ecosystem structure and function. Forest function is not static, but rather a risky asset that fluctuates and can decrease as a result of forest disturbance. Therefore, concepts such as resilience and insurance value as well effective policy formulation, management, and restoration are key to maintaining these benefits. This study estimates the insurance value that the public...

Relatively little is known about the dynamics of tropical urban forests, their phylogenetic diversity, as well as the socioeconomic and ecological factors that influence overall diversity across the urban landscape. However, permanent forest inventory and monitoring plot networks are increasingly being established across forests and cities of the world to monitor structural and functional attributes of urban forests, as well as ecosystem services. We analyzed a tropical, coastal urban forest in San Juan, Puerto Rico using metrics of phylogenetic diversity (PD), plant diversity, and...

Stream networks expand and contract through time, impacting chemical export, aquatic habitat, and water quality. Although recent advances improve prediction of the extent of the wetted channel network (L) based on discharge at the catchment outlet (Q), controls on the temporal variability of Lremain poorly understood and unquantified. Here we develop a quantitative, conceptual framework to explore how flow regime and stream network hydraulic scaling factors co‐determine the relative temporal variability in L(denoted here as the total wetted channel drainage density). Network hydraulic...

Quaking aspen (Populus tremuloides) is a valued, minor component on northeastern California landscapes. It provides a wide range of ecosystem services and has been in decline throughout the region for the last century. This decline may be explained partially by the lack of fire on the landscape due to heavier fire suppression, as aspen benefit from fire that eliminates conifer competition and stimulates reproduction through root suckering. However, there is little known about how aspen stand area changes in response to overlapping fire. Our study area in northeastern California on the...

Better understanding of the degree of “passability” needed to sustain robust sub‐populations upstream of barriers could help address and perhaps eliminate perceived trade‐offs between fish passage and other resource management goals. We used spatially explicit, individual‐based modeling to explore the population‐level consequences of various levels of upstream passability by (1) adult resident trout, and (2) juvenile salmon. In simulations of a stream network with widespread barriers, adult trout allowed to move upstream during only the highest 4% of streamflows sustained the distribution...

Forest biomass reductions in overgrown forests have the potential to provide hydrologic benefits in the form of improved forest health and increased streamflow production in water‐limited systems. Biomass reductions may also alter evaporation. These changes are generated when water that previously would have been transpired or evaporated from the canopy of the removed vegetation is transferred to transpiration of the remaining vegetation, streamflow, and/or non‐canopy evaporation. In this study, we combined a new vegetation‐change water‐balance approach with lumped hydrologic modelling...

Warming‐induced mountain pine beetle (Dendroctonus ponderosae; MPB) outbreaks have caused extensive mortality of whitebark pine (Pinus albicaulis; WBP) throughout the species’ range. In the highest mountains where WBP occur, they cross alpine treeline ecotones (ATEs) where growth forms transition from trees to shrub‐like krummholz, some of which survived recent MPB outbreaks. This observation motivated the hypothesis that ATEs are refugia for WBP because krummholz growth forms escape MPB attack and have the potential to produce viable seed. To test this hypothesis, we surveyed WBP mortality...

Owls play important cultural, ecological, and indicator roles throughout the world. Yet owls’ cryptic behavior has led to uncertainties about their basic ecology, including foraging, communication, and functional roles within the community, and potentially hindered the implementation of effective conservation measures. Here we demonstrate the potential for next‐generation GPS tags capable of recording high‐precision, minute‐by‐minute locations paired with other technologies to resolve some of these uncertainties. We combined high‐precision GPS tagging data with infrared (IR) video recorded...

Demographic models enhance understanding of drivers of population growth and inform conservation efforts to prevent population declines and extinction. For species with complex life histories, however, parameterizing demographic models is challenging because some life stages can be difficult to study directly. Integrated population models (IPMs) empower researchers to estimate vital rates for organisms that have cryptic or widely dispersing early life stages by integrating multiple demographic data sources. For a stream‐inhabiting frog (Rana boylii) that is declining through much of its...

Despite a multitude of small catchment studies, we lack a deep understanding of how variations in critical zone architecture lead to variations in hydrologic states and fluxes. This study characterizes hydrologic dynamics of 15 catchments of the U.S. Critical Zone Observatory (CZO) network where we hypothesized that our understanding of subsurface structure would illuminate patterns of hydrologic partitioning. The CZOs collect data sets that characterize the physical, chemical, and biological architecture of the subsurface, while also monitoring hydrologic fluxes such as streamflow,...