Search Results for: gross k
Assessing the relationship between microwave vegetation optical depth and gross primary production
At the global scale, the uptake of atmospheric carbon dioxide by terrestrial ecosystems through photosynthesis is commonly estimated through vegetation indices or biophysical properties derived from optical remote sensing data. Microwave observations of vegetated areas are sensitive to different components of the vegetation layer than observations in the optical domain […]
Contrasting changes in gross primary productivity of different regions of North America as affected by warming in recent decades
Ecosystem responses to the increasing warming in recent decades across North America (NA) are spatially heterogeneous and partly uncertain. Here we examined the spatial and temporal variability of warming across different eco-regions of NA using long-term (1979–2010) climate data (North America Regional Reanalysis (NARR)) with 3-hourly time-step and 0.25° × 0.25° spatial […]
Future emissions from ‘country of permafrost’ significant, must be factored into global climate targets
By the end of this century, permafrost in the rapidly warming Arctic will likely emit as much carbon dioxide and methane into the atmosphere as a large industrial nation, and potentially more than the U.S. has emitted since the start of the industrial revolution. But that’s only one possible future […]
New $764K award from Dept. of Energy will help better predict fate of permafrost carbon
As the Arctic endures another summer of record-breaking surface air temperatures, a team from NAU, led by Ecoss’ assistant research professor Christina Schädel, has been awarded a three-year, $764,000 grant from the Department of Energy to help improve models that predict what will happen to permafrost carbon as the Arctic […]
Modeling suggests fossil fuel emissions have been driving increased land carbon uptake since the turn of the 20th Century
Terrestrial vegetation removes CO2 from the atmosphere; an important climate regulation service that slows global warming. This 119 Pg C per annum transfer of CO2 into plants—gross primary productivity (GPP)—is the largest land carbon flux globally. While understanding past and anticipated future GPP changes is necessary to support carbon management, […]
GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes
Global terrestrial nitrogen (N) and phosphorus (P) cycles are coupled to the global carbon (C) cycle for net primary production (NPP), plant C allocation, and decomposition of soil organic matter, but N and P have distinct pathways of inputs and losses. Current C-nutrient models exhibit large uncertainties in their estimates […]
Leaf area index identified as a major source of variability in modeled CO2 fertilization
The concentration–carbon feedback (β), also called the CO2 fertilization effect, is a key unknown in climate–carbon-cycle projections. A better understanding of model mechanisms that govern terrestrial ecosystem responses to elevated CO2 is urgently needed to enable a more accurate prediction of future terrestrial carbon sink. We conducted C-only, carbon–nitrogen (C–N) […]
Enhanced peak growth of global vegetation and its key mechanisms
The annual peak growth of vegetation is critical in characterizing the capacity of terrestrial ecosystem productivity and shaping the seasonality of atmospheric CO2 concentrations. The recent greening of global lands suggests an increasing trend of terrestrial vegetation growth, but whether or not the peak growth has been globally enhanced still […]
Using near-infrared-enabled digital repeat photography to track structural and physiological phenology in Mediterranean tree-grass ecosystems
Tree-grass ecosystems are widely distributed. However, their phenology has not yet been fully characterized. The technique of repeated digital photographs for plant phenology monitoring (hereafter referred as PhenoCam) provide opportunities for long-term monitoring of plant phenology, and extracting phenological transition dates (PTDs, e.g., start of the growing season). Here, we […]