Search Results for: ning d

Quantifying the timescales over which exogenous and endogenous conditions affect soil respiration

Understanding how exogenous and endogenous factors and above-ground-below-ground linkages modulate carbon dynamics is difficult because of the influences of antecedent conditions. For example, there are variable lags between above-ground assimilation and below-ground efflux, and the duration of antecedent periods are often arbitrarily assigned. Nonetheless, developing models linking above- and below-ground […]

Closely Related Tree Species Differentially Influence the Transfer of Carbon and Nitrogen from Leaf Litter Up the Aquatic Food Web

Decomposing leaf litter in streams provides habitat and nutrition for aquatic insects. Despite large differences in the nutritional qualities of litter among different plant species, their effects on aquatic insects are often difficult to detect. We evaluated how leaf litter of two dominant riparian species (Populus fremontii and P. angustifolia) […]

Evapotranspiration comparisons between eddy covariance measurements and meteorological and remote-sensing-based models in disturbed ponderosa pine forests

Evapotranspiration (ET) comprises a major portion of the water budget in forests, yet few studies have measured or estimated ET in semi-arid, high-elevation ponderosa pine forests of the south-western USA or have investigated the capacity of models to predict ET in disturbed forests. We measured actual ET with the eddy […]

Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps

Soils and other unconsolidated deposits in the northern circumpolar permafrost region store large amounts of soil organic carbon (SOC). This SOC is potentially vulnerable to remobilization following soil warming and permafrost thaw, but SOC stock estimates were poorly constrained and quantitative error estimates were lacking. This study presents revised estimates […]

Researcher climbing a large redwood tree.

Plant Ecophysiology

Ecoss studies the interactions of plants with their physical and biotic environments at a fundamental level common to all organisms: gas exchange, energy balance, and water relations. We explore how plants make a living in diverse environments ranging from deserts to rainforests. A longstanding interest is the biophysical and ecological […]

Artist rendition of wildfire changing the future ecosystem of a forested area

Fire, Management, and the Global Carbon Cycle

Overview Fire, a natural ecological disturbance, has been suppressed in U.S. forests for much of the past century. This has prevented damage to property and protected timber resources, but has caused many forests to develop in an unnatural manner, resulting in dense stands of small trees that are now poised […]

Permafrost Carbon Network Logo showing the north portion of the globe in red, yellow and orange.

Global Change Synthesis

Permafrost Carbon Network Logo showing the north portion of the globe in red, yellow and orange.

Permafrost Carbon Network

Thousands of researchers worldwide are studying how global change affects ecosystems. Using models and field experiments, they add to our understanding of this area each day. However, individual studies sometimes only tell part of the whole story. By combining results from large numbers of studies, we can discern large-scale patterns across ecosystems, and make better estimates of how global change will affect our environment. Our work on global change synthesis combines several statistical techniques with modeling approaches. (more…)

Fossil Creek, Arizona with fall foliage in background.

Riparian Ecosystems

Aquatic ecosystems in the southwestern US are among the most threatened in the country: rates of species loss are high, with few remaining refuges for natives, and water extraction for human use and diversion for power generation impose major demands on the defining feature of aquatic ecosystems: water. Work at […]