Treesearch

Wilderness management can be tricky. The conservationist Aldo Leopold, who is considered by many to be the father of wildlife ecology and the U.S. wilderness system, was probably thinking about this when he said, “All conservation of wildness is self-defeating, for to cherish we must Wilderness managers in North Cascades National Park opted for chemical treatments to remove invasive fish species. see and fondle, and when enough have seen and fondled, there is no wilderness left to cherish.”

Environmental DNA (eDNA) sampling - which enables inferences of species’ presence from genetic material in the environment - is a powerful tool for sampling rare fishes. Numerous studies have demonstrated that eDNA sampling generally provides greater probabilities of detection than traditional techniques (e.g., Thomsen et al. 2012; McKelvey et al. 2016; Valentini et al. 2016; Wilcox et al. 2016). In contrast, Ulibarri et al. (2017) and Perez et al. (2017) reported unusually low rates of eDNA detection at sites known to be occupied by the target species. These authors claim their results...

Bats have been portrayed as important consumers of mosquitoes, but evidence supporting this claim is surprisingly scant. We collected the fecal material of 2 common North American bats at 22 sites in Wisconsin, United States and screened samples for mosquitoes using a recently improved molecular method for detecting arthropod DNA. Overall, we detected 17 discrete operational taxonomic units assigned to the mosquito family (Diptera: Culicidae), 15 of which were assigned at the species level. We detected mosquitoes in 71.9% of samples and at all sampling sites for little brown bats (Myotis...

In nearly all large-scale terrestrial ecosystem models, soil respiration is represented as a function of soil temperature. However, the relationship between soil respiration and soil temperature is highly variable across sites and there is often a pronounced hysteresis in the soil respiration-temperature relationship over the course of the growing season. This phenomenon indicates the importance of biophysical factors beyond just temperature in controlling soil respiration. To identify the potential mechanisms of the seasonal soil respiration-temperature hysteresis, we developed a set of...

Oaks are not sustainable in many upland temperate forests because of poor recruitment resulting from natural regeneration. Artificial regeneration is an alternative to natural regeneration, but is difficult, in part, due to large variation in seedling quality. In this study, we examined the effects of acorn size and mass on nursery seedling morphological parameters commonly used to quantify seedling quality, and we determined if genetic factors affected these relationships. Acorns were collected from six open-pollinated orchard trees (i.e., six half-sib families), and were separated into...

Warming temperatures are projected to greatly alter many forests in the Pacific Northwest. MC2 is a dynamic global vegetation model, a climate-aware, process-based, and gridded vegetation model. We calibrated and ran MC2 simulations for the Blue Mountains Ecoregion, Oregon, USA, at 30 arc-second spatial resolution. We calibrated MC2 using the best available spatial datasets from land managers. We ran future simulations using climate projections from four global circulation models (GCM) under representative concentration pathway 8.5. Under this scenario, forest productivity is projected to...

Most previous studies of resting habitat for fishers (Pekania pennanti) in the Pacific coastal region of the western United States and Canada were focused on habitat conditions within rest sites (typically ≤0.5 ha), which include the rest structure (e.g., live tree, snag, log) at its center. Studies of selection for rest structures were sparse and compared characteristics of rest structures to those occurring within rest sites; none investigated selection by sampling resource availability throughout the study area. In addition, limited data were available on the use of rest microsites...

Global increases in nitrogen deposition may alter forest structure and function by interferingwith plant nitrogen metabolism (e.g., assimilation and partitioning) and subsequent carbon assimilation, but it is unclear how these responses to nitrogen deposition differ among species. In this study, we conducted a 2-year experiment to investigate the effects of canopy addition of nitrogen (CAN) on leaf nitrogen assimilation and partitioning in three subtropical forest plants (Castanea henryi, Ardisia quinquegona, and Blastus cochinchinensis). We hypothesized that responses of leaf nitrogen...

Growing-season burns are increasingly used in upland hardwood forest for multiple forest management goals. Many species of reptiles and amphibians are ground-dwelling, potentially increasing their vulnerability to prescribed fire, especially during the growing-season when they are most active. We used drift fences with pitfall traps to experimentally assess how herpetofaunal species and communities responded to early, growing-season burns, dormant-season burns, and unburned controls. We documented no adverse effects of either growingseason burns or dormant-season burns on any common...

Base cations, such as potassium (K+), calcium (Ca2+) and magnesium (Mg2+), are essential nutrients for plant growth and their atmospheric inputs can buffer the effect of acid deposition by nitrogen (N) and sulphur (S) compounds. However, the spatial variation in atmospheric deposition of these base cationic nutrients is less understood compared with N and S deposition. By synthesizing bulk deposition data for K+, Ca2+ and Mg2+, we assessed their annual rates and spatial characteristics at 34 forested sites across China. Our synthesis showed relatively high levels of bulk deposition of base...