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The problem of how the scale, or spatial resolution, of reflectance data impacts retrievals of vegetation leaf area index (LAI) is addressed in this article. We define the goal of scaling as the process by which it is established that LAI values derived from coarse resolution sensor data equal the arithmetic average of values derived independently from fine(More)
We report above-ground biomass (AGB), basal area, stem density and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha⁻¹ (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region(More)
The identification of a universal law that can predict the spatiotemporal structure of any entity at any scale has long been pursued. Thermodynamics have targeted this goal, and the concept of entropy has been widely applied for various disciplines and purposes, including landscape ecology. Within this discipline, however, the uses of the entropy concept(More)
We report on the first results of the HyEco'04 campaign carried out in summer 2004 as a joint activity of a bi-national team of Belgian and Dutch researchers. This integrated approach of assessing the complexity of managed natural ecosystems is a demonstrator case for recent focus of airborne imaging spectroscopy activities on ecotones. The floodplain(More)
In a recent paper [Landscape Ecol. 15: 591–601 (2000)] He et al. described an aggregation index AI i to measure pixel aggregation within a single class i. We show that the commonly used shape index SI i is related to the proposed aggregation metric as SI i = ⌽(A i) + AI i (1 − ⌽(A i)), with ⌽(A i) dependent on class area A i only. Moreover , it is shown(More)
Large tropical trees and a few dominant species were recently identified as the main structuring elements of tropical forests. However, such result did not translate yet into quantitative approaches which are essential to understand, predict and monitor forest functions and composition over large, often poorly accessible territories. Here we show that the(More)
Analysis of a recently validated fragmentation index, named 'coherence', shows a direct relationship with the Simpson and Shannon indices. Since these diversity metrics are also denoted as 'entropy metrics', it can be accepted that patch size heterogeneity can adequately be described by an entropy metric. Since both indices are used to determine the entropy(More)
Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this(More)
Gap disturbance is assumed to maintain species diversity by creating environmental heterogeneity. However, little is known about how interactions with neighbours, such as competition and facilitation, alter the emerging gap patterns after extreme events. Using a spatially explicit community model we demonstrate that negative interactions, especially(More)
CONTEXT Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific(More)
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