Project Tag: 2010-2019

An enduring challenge in ecology is to characterise and understand species richness patterns in tropical regions. Species richness maps produced by stacking species distribution model (SDM) range maps could prove useful in this regard, but little attention has been given to this approach. Here we generate a species richness map by stacking the ranges of … Continue reading Inferring diversity patterns along an elevation gradient from stacked SDMs: A case study on Mesoamerican ferns

Borneo contains some of the world's most biodiverse and carbon-dense tropical forest, but this 750000km2 island has lost 62% of its old-growth forests within the last 40 years. Efforts to protect and restore the remaining forests of Borneo hinge on recognizing the ecosystem services they provide, including their ability to store and sequester carbon. Airborne laser scanning … Continue reading Estimating aboveground carbon density and its uncertainty in Borneo’s structurally complex tropical forests using airborne laser scanning

Topography is a key driver of tropical forest structure and composition, as it constrains local nutrient and hydraulic conditions within which trees grow. Yet, we do not fully understand how changes in forest physiognomy driven by topography impact other emergent properties of forests, such as their aboveground carbon density (ACD). Working in Borneo – at … Continue reading Topography shapes the structure, composition and function of tropical forest landscapes

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 of … Continue reading Blind image fusion for hyperspectral imaging with the directional total variation

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

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 (sensitive … Continue reading Extreme and Highly Heterogeneous Microclimates in Selectively Logged Tropical Forests

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 by … Continue reading Effect of Tree Phenology on LiDAR Measurement of Mediterranean Forest Structure

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

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

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