Blind image fusion for hyperspectral imaging with the directional total variation

Hyperspectral imaging is a cutting-edge type of remote sensing used for mapping vegetation properties, rock minerals and other materials. A major drawback of hyperspectral imaging devices is their intrinsic low spatial resolution. In this paper, we propose a method for increasing the spatial resolution of a hyperspectral image by fusing it with an image ofContinue reading “Blind image fusion for hyperspectral imaging with the directional total variation”

Mapped aboveground carbon stocks to advance forest conservation and recovery in Malaysian Borneo

Forest carbon stocks in rapidly developing tropical regions are highly heterogeneous, which challenges efforts to develop spatially-explicit conservation actions. In addition to field-based biodiversity information, mapping of carbon stocks can greatly accelerate the identification, protection and recovery of forests deemed to be of high conservation value (HCV). We combined airborne Light Detection and Ranging (LiDAR) with satellite imaging andContinue reading “Mapped aboveground carbon stocks to advance forest conservation and recovery in Malaysian Borneo”

Extreme and Highly Heterogeneous Microclimates in Selectively Logged Tropical Forests

Microclimate within forests influences ecosystem fluxes and demographic rates. Anthropogenic disturbances, such as selective logging can affect within-forest microclimate through effects on forest structure, leading to indirect effects on forests beyond the immediate impact of logging. However, the scope and predictability of these effects remains poorly understood. Here we use a microclimate thermal proxy (sensitiveContinue reading “Extreme and Highly Heterogeneous Microclimates in Selectively Logged Tropical Forests”

Effect of Tree Phenology on LiDAR Measurement of Mediterranean Forest Structure

Retrieval of forest biophysical properties using airborne LiDAR is known to differ between leaf-on and leaf-off states of deciduous trees, but much less is understood about the within-season effects of leafing phenology. Here, we compare two LiDAR surveys separated by just six weeks in spring, in order to assess whether LiDAR variables were influenced byContinue reading “Effect of Tree Phenology on LiDAR Measurement of Mediterranean Forest Structure”

Enhancing of accuracy assessment for forest above-ground biomass estimates obtained from remote sensing via hypothesis testing and overfitting evaluation

The evaluation of accuracy is essential for assuring the reliability of ecological models. Usually, the accuracy of above-ground biomass (AGB) predictions obtained from remote sensing is assessed by the mean differences (MD), the root mean squared differences (RMSD), and the coefficient of determination (R2) between observed and predicted values. In this article we propose a more thorough analysis ofContinue reading “Enhancing of accuracy assessment for forest above-ground biomass estimates obtained from remote sensing via hypothesis testing and overfitting evaluation”

Synergistic use of Landsat 8 OLI image and airborne LiDAR data for above-ground biomass estimation in tropical lowland rainforests

Here we estimated AGB of primary tropical forests using airborne LiDAR and Landsat 8 OLI. We found that Landsat 8 OLI’s textures show greater potential to estimate AGB compared with LiDAR, and a synergistic use of Landsat 8 OLI and LiDAR outperforms the independent-data models in estimating biomass of tropical lowland rainforests. Phua, M.H. et al. Forest Ecology andContinue reading “Synergistic use of Landsat 8 OLI image and airborne LiDAR data for above-ground biomass estimation in tropical lowland rainforests”

Detecting the fingerprint of drought across Europe’s forests: do carbon isotope ratios and stem growth rates tell similar stories?

We evaluated the effectiveness of using the isotopic ratio of 13C to 12C stored in wood, referred to as δ13C, and stem basal area increments (BAI) as indicators of drought in European trees. Using tree ring data from over 3000 trees, we found that while δ13C responded strongly and consistently to drought across a diverse group ofContinue reading “Detecting the fingerprint of drought across Europe’s forests: do carbon isotope ratios and stem growth rates tell similar stories?”

Effects of plot size, stand density, and scan density on the relationship between airborne laser scanning metrics and the Gini coefficient of tree size inequality

Estimation of the Gini coefficient (GC) of tree sizes using airborne laser scanning (ALS) can provide maps of forest structure across the landscape, which can support sustainable forest management. A challenge arises in determining the optimal spatial resolution that maximizes the stability and precision of GC estimates, which in turn depends on stand density orContinue reading “Effects of plot size, stand density, and scan density on the relationship between airborne laser scanning metrics and the Gini coefficient of tree size inequality”

Riparian reserves in oil palm can protect forest bird communities

This study looks into the effectiveness of protecting riparian forest strips on forest birds. We characterized bird communities of 28 sites in an oil palm‐forest mosaic in Sabah, Malaysia using 6,104 encounters from 840 point counts. Results show that riparian reserve width, forest quality, and amount of forest cover are important in supporting rich birdContinue reading “Riparian reserves in oil palm can protect forest bird communities”

An Alternative Approach to Using LiDAR Remote Sensing Data to Predict Stem Diameter Distributions across a Temperate Forest Landscape

We apply a spatially-implicit, allometry-based modelling approach to predict stem diameter distributions (SDDs) from low density airborne LiDAR data in a heterogeneous, temperate forest in Ontario, Canada. Using a recently published algorithm that relates the density, size, and species of individual trees to the height distribution of first returns, we estimated parameters that succinctly describeContinue reading “An Alternative Approach to Using LiDAR Remote Sensing Data to Predict Stem Diameter Distributions across a Temperate Forest Landscape”