Treesearch

Losses of C and N from the forest floor and top 20-cm of soil were estimated following separate severe wildfires at two Long-Term Soil Productivity sites in the Sierra Nevada of California, USA. Experimental treatments applied 20 years prior to the wildfires included factorial combinations of 1) organic matter (OM) removal following clear-cut harvesting (SO, stem only harvest, WTH, whole-tree harvest, and WTH + FF, WTH plus the forest floor removal), 2) soil compaction (three levels of intensity), and 3) with and without understory vegetation control. Wildfires caused complete losses of...

Effective management of wildlife populations threatened by disease requires accurate predictions about the consequences of intervention. However, generating such predictions is challenging, especially for organisms with complex life histories that are also threatened by climate change, such as montane amphibians. Cascades frogs (Rana cascadae) in northern California have experienced dramatic declines associated with the fungal pathogen Batrachochytrium dendrobatidis(Bd), and remnant populations are also threatened by changing climate conditions. We evaluated the population-level impacts of...

American pikas (Ochotona princeps), small mammals related to rabbits, occur in mountainous regions of western North America, where they live in shattered-rock habitats (talus). Aspects of their physiology and life history create situations that appear to put pikas at risk from warming climates. Some low-elevation, warm sites that historically harbored pikas have become extirpated, and the assumption is that these will not be re-colonized under current climate trends. Unexpectedly, in 2021, we found that pikas had re-colonized two very warm, low-elevation, dry sites in eastern California,...

For agricultural areas facing water scarcity, sustainable water use policy relies on irrigation information that is timely and at a high resolution, but existing publicly available water use data are often insufficient for monitoring compliance or understanding the influence of policy on individual farmer decisions. This study attempts to fill this data gap by using remote sensing to map annual irrigation quantity at the field-scale within the central Ogallala aquifer region of the United States. We compiled in situ annual irrigation volume data at the field scale in the Republican River...

Sieve elements of many angiosperms contain structural phloem proteins (P-proteins) that can interact to create large P-protein bodies. P-protein bodies can occlude sieve plates upon injury but the range of functional and physiological roles of P-proteins remains uncertain, in part because of challenges in labeling and visualization methods. Here, we show that a reciprocal oligosaccharide probe, OGA488, can be used in rapid and sensitive labeling of P-protein bodies in Arabidopsis, poplar, snap bean and cucumber in histological sections. OGA488labeling of knockouts of the two Arabidopsis...

Understanding the contribution of neutral and adaptive evolutionary processes to population differentiation is often necessary for better informed management and conservation of rare species. In this study, we focused on Pinus torreyanaParry (Torrey pine), one of the world's rarest pines, endemic to one island and one mainland population in California. Small population size, low genetic diversity, and susceptibility to abiotic and biotic stresses suggest Torrey pine may benefit from interpopulation genetic rescue to preserve the species' evolutionary potential. We leveraged reduced...

Climate change is a crucial factor in increasing wildfire risks, where warmer and drier conditions, increased drought periods and increased lightning strikes have made many areas more susceptible to burning. This special issue focuses on Wildfire and Hydrological Processes,exploring how wildfire has impacted watersheds and water resources. The manuscripts in this collection underscore how wildfire can change the nature of vegetation, characteristics of soils, hydrological flow paths, and residence times of water in the critical zone, and provide new insights toward predictability of...

The magnitude of sediment yield from headwater catchments is controlled by the interactions among hydrology, geomorphology, and soil disturbance. In montane regions like the Sierra Nevada, snow is one of the main factors controlling the timing and magnitude of hydrological fluxes. However, the role of snow on modulating spatial and temporal variation of sediment yield remains unclear. Using 120-site years of sediment yield data from 10 headwater catchments (drainage area 50–475 ha), we examined the sediment yield characteristics across an elevational gradient (1,777–2,381 m elevation) in...

Suspended sediment transport in montane headwaters is important to water quality and nutrient balances. However, predictions of sediment source and transport can be difficult, in part, because of a changing climate and increasing frequencies of disturbances. We used observations from 10 headwater streams in water year (WY; starting on 1st October ending on 30th September) 2007–2009 and 2013–2018 to determine the potential impacts of climate and forest management on suspended sediment delivery. We analysed hysteretic responses of suspended sediment for 76 events in five headwater catchments...

Prescribed fire is used extensively as a management tool in fire-adapted landscapes of the American West to maintain ecosystem structure and function while reducing wildfire risk. Seasonally specific prescribed fire is used by many Indigenous groups to increase the quality and quantity of cultural resources and promote desired patterns of habitat diversity. Traditionally, the Karuk and Yurok Tribes of California applied fire in tanoak (Notholithocarpus densiflorus,Fagaceae) acorn gathering areas during the fall to reduce infestation in acorns by larvae of the filbertworm (Cydia latiferreana...