Treesearch

Ecosystem responses to environmental change are usually studied solely using aboveground (usually leaf) traits. However, belowground plant traits, such as fine roots and coarse belowground organs, likely play a crucial role in ecosystem response, especially under aridifcation. We conducted a literature survey on belowground plant traits along aridity gradients in temperate grasslands to propose which effect traits might be connected with abrupt vegetation changes that would occur with aridification due to environmental change. With increasing aridity, seasonal regeneration decreasingly...

Climate warming is rapid in the Arctic, yet impacts to biological systems are unclear because few long-term studies linking biophysiological processes with environmental conditions exist for this data-poor region. In our study spanning 25 years in the Alaskan Arctic, we demonstrate that climate change is affecting the timing of freeze-thaw cycles in the active layer of permafrost soils and altering the physiology of arctic ground squirrels (Urocitellus parryii). Soil freeze has been delayed and, in response, arctic ground squirrels have delayed when they up-regulate heat production during...

Providing forest biomass estimates with desired accuracy and precision for small areas is a key challenge to incorporating forest carbon offsets into commodity trading programs. Enrolled forest carbon projects and verification entities typically rely on probabilistically sampled field data and design-based (DB) estimators to estimate carbon storage and characterize uncertainty. However, this methodology requires a large amount of field data to achieve sufficient precision and collection of these data can be prohibitively expensive. This has spurred interest in developing regional-scale...

Protecting and enhancing forest carbon sinks is considered a natural solution for mitigating climate change. However, the increasing frequency, intensity, and duration of droughts due to climate change can threaten the stability and growth of existing forest carbon sinks. Extreme droughts weaken plant hydraulic systems, can lead to tree mortality events, and may reduce forest diversity, making forests more vulnerable to subsequent forest disturbances, such as forest fires or pest infestations. Although early warning metrics (EWMs) derived using satellite remote sensing data are now being...

Background and Aims: In dryland ecosystems, conifer species are threatened by more frequent and severe droughts, which can push species beyond their physiological limits. Adequate seedling establishment will be critical for future resilience to global change. We used a common garden glasshouse experiment to determine how seedling functional trait expression and plasticity varied among seed sources in response to a gradient of water availability, focusing on a foundational dryland tree species of the western USA, Pinus monophylla. We hypothesized that the expression of growth-related...

In 2019, approximately 103 participants from the U.S. Department of Agriculture, Forest Service (Forest Service), NASA (including representatives from SMAP, NISAR , ICESat-2 , GEDI , CMS ), and other federal, private and academic entities attended the USFS-NASA Joint Applications Workshop. The objective of this workshop was to increase awareness and understanding of the capabilities of NASA data products, as well as to develop connections and strengthen partnerships between NASA and the Forest Service. In this vein the workshop sought to identify opportunities for collaboration between the...

This guide builds on existing frameworks to link ecological and socio-economic vulnerability. Vulnerability assessments use spatially explicit ecological and economic data to describe the exposure, sensitivity, and adaptive capacity of forest resources and local communities to potential hazards. This work describes ways to measure each aspect of vulnerability and ways to aggregate data that makes for more straightforward analysis. Knowledge about the relative vulnerability of natural resources and the communities that depend on them can help prioritize and inform management and guide...

Background: In ecosystems where fire has been excluded, pyrosilviculture can restore some processes historically maintained by fire while mitigating risk where fire is inevitable. Pyrosilviculture in crown fire-adapted forests is, however, limited by insight into the temporal window of fire return matching canopy seedbank development. Here, we characterized demographic responses to fire and non-native pine pitch canker infection in a chronosequence of serotinous bishop pine stands burned at high-severity to quantify (1) temporal patterns of seedbank development given seed viability and...

Dryland woodland ecosystems worldwide have experienced widespread drought- and heat-related tree mortality events coupled with extreme wildfire behavior. In contrast to other forest types where the emphasis has been on the silvicultural enhancement of ecosystem resilience and restoration of structural heterogeneity, limited frameworks are available for management to improve drought resilience in semiarid woodlands. This challenge is especially acute in pinyon-juniper woodlands, a dominant vegetation type across western North America that has experienced extensive tree die-off over the past...

A recent climate-induced tree mortality event in California, USA has led to dramatic landscape-level changes in the southern Sierra Nevada. Wide-spread conifer mortality was documented in habitat occupied by fisher (Pekania pennanti), a mature-forest associated species of conservation concern in this region. We analyzed fisher scats collected on the Sierra National Forest from the pre-tree-mortality period (PreTM, 2011-2013) and posttree-mortality period (PostTM, 2017-2018). We used DNA metabarcoding to successfully identify taxa and summarized diet composition for 109 PreTM and 102 PostTM...