[1] Many regions of the world are dependent on snow cover for frost protection and summer water supplies. These same predominantly forested, with forests highly vulnerable to change. Here we combine a meta-analysis observational studies across globe modeling show that in average December-January-February (DJF) temperatures greater than −1°C, forest reduces duration by 1–2 weeks compared adjacent open areas. This occurs because dominant effect shifts from slowing snowmelt shading blocking...

Abstract Forests modify snow processes and affect water storage as well disappearance timing. However, forest influences on accumulation ablation vary with climate topography are therefore subject to temporal spatial variability. We utilize multiple years of observations from across the Pacific Northwest, United States, assess forest–snow interactions in relatively warm winter conditions characteristic maritime transitional maritime–continental climates. (a) quantify difference magnitude...

Abstract Many plot‐scale studies have shown that snow‐cover dynamics in forest gaps are distinctly different from those open and continuously forested areas, the potential to alter magnitude timing of snowmelt. However, watershed‐level impacts canopy gap treatment on streamflows largely unknown. Here, we present first research explicitly assesses impact seasonal particularly late‐season low flows at watershed scale. To model forest–snow interactions gaps, made major enhancements a widely...

Abstract When formulating a hydrologic model, scientists rely on parameterizations of multiple processes based field data, but literature review suggests that more frequently people select were included in pre‐existing models rather than re‐evaluating the underlying experiments. Problems arise when limited data exist, “trusted” approaches do not get reevaluated, and sensitivities fundamentally change different environments. The physics dynamics snow interception by conifers is just such...

Abstract Controlled field experiments to disentangle the effect of canopy density from climate on snowpack dynamics are limited by underlying linkage between and climate. Thus, based observations alone, it is not well understood how variations in can affect snow processes under different regimes. To address this knowledge gap, study uses a physics‐based modeling approach evaluate sensitivity across gradients Western U.S. as represented 228 Snow Telemetry (SNOTEL) sites. Within model, we...

Abstract Forests modify snow accumulation and ablation rates as well overall storage amounts durations, with multiple processes acting simultaneously often in different directions. To synthesize complex forest–snow relations help guide near‐term management decisions, we present a decision tree. The framework is based on hypothesized hierarchy of associated variables that predict forest effects storage. In locations high wind speeds, forests enhance magnitude duration relative to open areas....

Abstract The Nooksack River has its headwaters in the North Cascade Mountains and drains an approximately 2000 km 2 watershed northwestern Washington State. timing magnitude of streamflow a snowpack‐dominated drainage basin such as are strongly influenced by temperature precipitation. Projections future climate made general circulation models (GCMs) indicate increases variable changes precipitation for basin. Understanding response river to change is crucial regional water resources planning...

Abstract Forests cover almost 40% of the seasonally snow‐covered regions in North America. However, operational snow networks are located primarily forest clearings, and optical remote sensing cannot see through tree canopies to detect snowpack. Due complex influence on snowpack duration, ground observations forests essential. We therefore consider effectiveness different strategies observe area under forests. At our study location Pacific Northwest, we simultaneously deployed fiber‐optic...

[1] Tree canopy snow interception is a significant hydrological process, capable of removing up to 60% from the ground snowpack. Our understanding has been limited by our ability measure whole water storage in an undisturbed forest setting. This study presents relatively inexpensive technique for directly measuring using interceptometer, adapted Friesen et al. (2008). The interceptometer composed four linear motion position sensors distributed evenly around tree trunk. We incorporate trunk...

Abstract Spatially distributed snow depth and duration data were collected over two to four seasons during water years 2011–2014 in experimental forest plots within the Cedar River Municipal Watershed, 50 km east of Seattle, Washington, USA. These 40 × m plots, situated on western slope Cascade Range, include unthinned second‐growth coniferous forests, variable density thinned gaps which a 20 diameter (approximately equivalent one tree height) gap was cut middle each plot, old‐growth forest....

Whereas the evolution of snow cover across forested mountain watersheds is difficult to predict or model accurately, presence absence easily observable and these observations contribute improved models. We engaged citizen scientists collect timing distributed disappearance over three seasons Pacific Northwest, U.S.A. . The primary goal project was build a more spatially robust dataset documenting influence forest on disappearance, public outreach secondary goal. Each year's effort utilized...

Abstract Objective Despite decades of restoration work, Chinook Salmon Oncorhynchus tshawytscha in the Pacific Northwest remain under protection U.S. Endangered Species Act (ESA). Skagit River basin play a vital role abundance and recovery Puget Sound Evolutionarily Significant Unit, which is currently listed as threatened ESA. The stream‐type juvenile (STJ) life history pattern has higher ocean survival to adult stage (i.e., productivity) than that parr or fry out‐migrants, improvement STJ...

Forest thinning and gap creation are being implemented across the western United States of America (USA) to reduce wildfire forest mortality risk as climate warms. The Eastern Cascades in Washington, USA, is a transitional zone between maritime continental conditions represents data observations describing relationship density snowpack. We collected 3 years snow range densities characterize how management efforts this region may influence magnitude duration storage. Observations indicate...

When formulating a hydrologic model, scientists rely on parameterizations of multiple processes based field data, but literature review suggests that more frequently people select were included in pre-existing models rather than re-evaluating the underlying experiments. Problems arise when limited data exist, “trusted” approaches do not get reevaluated, and fundamentally change different environments. The physics dynamics snow interception by conifers, including both loading unloading snow,...