Treesearch

Bedrock vadose zone water storage (i.e., rock moisture) dynamics are rarely observed but potentially key to understanding drought responses. Exploiting a borehole network at a Mediterranean blue oak savanna site—Rancho Venada—we document how water storage capacity in deeply weathered bedrock profiles regulates woody plant water availability and groundwater recharge. The site is in the Northern California Coast Range within steeply dipping turbidites. In a wet year (water year 2019; 647 mm of precipitation), rock moisture was quickly replenished to a characteristic storage capacity,...

Water age and flow pathways should be related; however, it is still generally unclear how integrated catchment runoff generation mechanisms result in streamflow age distributions at the outlet. Here, we combine field observations of runoff generation at the Dry Creek catchment with StorAge Selection (SAS) age models to explore the relationship between stream water age and runoff pathways. Dry Creek is a 3.5 km2catchment in the Northern California Coast Ranges with a Mediterranean climate, and, despite an average rainfall of ≈1,800 mm/yr, is an oak savannah due to the limited hillslope...

Hurricanes and tropical storms (TS) are infrequent but disastrous events to human lives, social activities, and terrestrial ecosystems in coastal regions. Using the Environmental Protection Agency (US-EPA)'s Hydrologic and Water Quality System (HAWQS) model, principal component analysis (PCA), and principal factor analysis (PFA), we estimated impacts of multiple hurricanes and TS on hydrological processes in agricultural and forested watersheds. Five hurricanes and four TS that passed near or through the Apalachicola-Chattahoochee-Flint River basin (ACFRB) of the Florida panhandle from...

Stream discharge is a key hydrological factor for water supply planning, wetland loss investigation,ecological service assessment, and climate change impact estimation. Conceptually, stream discharge is expected to be highly and positively related to precipitation. In reality, however, such a relationship may be weakerbecause precipitation characteristics are affected by local climate of watersheds. For many watersheds aroundthe world, a vast amount of precipitation data are readily available but the stream discharge data are very lim-ited or unavailable. It would be time-saving and...

Evapotranspiration (ET) provides important information for hydrological studies, includingestimating plant water requirements which can be derived from remote sensing data or simulatedusing hydrological models. In this study, ET derived from the Moderate Resolution Imaging Spectrometer(MODIS) was compared with ET simulated by the calibrated and validated Soil and WaterAssessment Tool (SWAT) model for the Big Sunflower River watershed (BSRW) in Mississippi. Thecomparisons were made based on 8-day, 1-month, seasonal, and annual timescales. The coefficientsof variation (COVs) for the 8-day,...

Wildfires are becoming more frequent and destructive in California, and it is essential to quantify their potential impacts on drinking water utilities. This study aims to measure the severity of wildfires in each California water utility based on the exposure frequency and the extent of area burned by wildfires in each service area. Our quantitative models show an association between water utility characteristics and their vulnerability to wildfires. Findings indicate that wildfire vulnerability is higher in government-owned utilities than private ones, utilities primarily relying on...

New approaches to managing climate change uncertainty rely on integrating innovative forest management practices with adaptive management techniques and robust decision-support strategies. Forest management alternatives for a changing climate can enhance ecosystem health and sustainability while ensuring the flow of ecosystem services, such as water, wildlife, biodiversity, recreation, and ecosystem resilience. Ideally, these methods will help reverse the decline in ecosystem function from associated ecological disturbances, such as drought, wildfire, insects, diseases, or invasive...

Soil physical and chemical properties play important roles in mass loss during soil-block tests but the relationship between soil properties and the decay caused by brown-rot and white-rot fungi remains unclear. The objective of this study was to investigate the soil effects on the decay resistance of pine (Pinus spp.) and poplar (Liriodendron tulipifera L.) blocks. The properties of soil from nine different sources (six from Idaho, one from Mississippi, one from Wisconsin, and one from Oregon) were characterized for soil texture, sieved bulk density, water-holding capacity, pH, organic...

Fire occurring in the chaparral behaves as a crown fire, a dual-layer fire that typically ignites in a dead surface fuel layer and transitions to an elevated live crown layer where it continues to spread. In chaparral fuels including chamise, a dominant species in southern California, flame transition to live crown fuels is associated with higher spread rates and greater fire intensity. Despite the relative importance of surface-to-crown transition and crown fire spread, most fire models represent chaparral fire as surface fire, therefore omitting key behavior processes driving this fire...

Management problem: Widespread failure of oak regeneration and subsequent loss of the oakcomponent has been reported across Eurasia and the Americas. The oak regeneration issuehas been linked to changing disturbance regimes, including the lack of fire. Burning used incombination with stand thinning creates conditions that should be conducive to oakregeneration establishment and recruitment, including increased understory light anddecreased woody plant competition.Management need: Managers are using thinning and prescribed fire prescriptions aimed atrestoring hardwood dominance in upland...