Accurate measurement of forest productivity is fundamental to understand the carbon balance of forested ecosystems. Recent changes in climate highlight the importance of developing methods to measure forest productivity so that sound economic and environmental decision can be made. Efforts to measure forest productivity across the landscape using remote sensing...
The spatial distribution of forest disturbance is commonly calculated using a satellite imagery-driven bi- or tri-temporal change analysis. Working in Colombia’s Cordillera de los Picachos National Natural Park – a region of consistent cloud cover and dramatic topographic relief – a change assessment with such infrequent observations cannot capture long-term...
Forest canopy cover presents a major challenge for remote sensing of fractional snow-covered area (ƒSCA). Snow cover is systematically underestimated where satellites sensors cannot penetrate the forest canopy. Current canopy adjustments scale observable ƒSCA with the vegetation fraction, assuming that snow cover distributions are similar between sub-canopy and open locations....
Broad-scale estimates of above ground forest biomass (AGB) are typically produced by applying individual-tree equations to inventory data consisting of measurements from probabilistically or purposively selected trees. The associated uncertainty for these estimates depends primarily on three sources of error that interact and propagate: (1) measurement error, the quality of...
The over-arching theme of this work is that soil data affect the performance and realism of vegetation models with particular focus on their ability to predict or explain disturbances such as fire or disease. We tested the sensitivity of the Excel version of the 3-PG model to soil properties and...
Earth’s atmosphere is unequivocally warming due to CO₂ and other greenhouse gas (GHG) emissions from human activities and this is having widespread impacts on forest ecosystems that provide important services to human societies. Forest ecosystems help regulate atmospheric CO2 concentrations by sequestering carbon in tree biomass and soils, which is...
In estimating aboveground forest biomass (AGB), three sources of error that interact and propagate include (i) measurement error, the quality of the tree-level measurement data used as inputs for the individual-tree equations; (ii) model error, the uncertainty about the equations of the individual trees; and (iii) sampling error, the uncertainty...
Understanding plant photosynthesis, or Gross Primary Production (GPP), is a crucial aspect of quantifying the terrestrial carbon cycle. Remote sensing approaches, in particular multi-angular spectroscopy, have proven successful for studying relationships between canopy-reflectance and plant-physiology processes, thus providing a mechanism to scale up. However, many different instrumentation designs exist and...
The Mongolian Steppe is one of the largest remaining grassland ecosystems. Recent studies have reported widespread
decline of vegetation across the steppe and about 70% of this ecosystem is now considered degraded. Among
the scientific community there has been an active debate about whether the observed degradation is related to...
The Mongolian Steppe is one of the largest remaining grassland ecosystems. Recent studies have reported widespread
decline of vegetation across the steppe and about 70% of this ecosystem is now considered degraded. Among
the scientific community there has been an active debate about whether the observed degradation is related to...
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Thomas Hilker1*, Enkhjargal Natsagdorj2, Richard H. Waring1, Alexei Lyapustin3, Yujie Wang
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