Spatio-temporal distribution patterns of species in response to natural and anthropogenic drivers provide insight into the ecological processes that determine community composition. We investigated determinants of ecological structure in a species assemblage of 4 closely related primate species of the family Cheirogaleidae (Microcebus berthae, Microcebus… (More)
In managed forests, the occurrence of deadwood (DW) can be regarded as a stochastically rare event with strong clumping and high local variability (Meyer in Forstwissenschaftliches Centralblatt 118:167–180, 1999). Traditional sampling techniques, such as Fixed Area Sampling, Angle Count Sampling and Line Intersect Sampling, do not regard this fact and may… (More)
For a current inventory using double sampling for stratification with a reduced second-phase sample size, compared with a previous inventory, we develop a three-phase sampling procedure that exploits plot data from the previous inventory or their updates based on a growth model to increase precision. The three-phase procedure combines double sampling for… (More)
Please see www.drylandscience.org for more information on the DSD and for the findings and White Papers of Working Groups 1 and 2.
The efficiency of sample-based indices proposed to quantify the spatial distribution of trees is influenced by the structure of tree stands, environmental heterogeneity and degree of aggregation. We evaluated 10 commonly used distance-based and 10 density-based indices using two structurally different stands of wild pistachio trees in the Zagros woodlands,… (More)
We extend the well-known double sampling for stratification sampling scheme by cluster subsampling to a three-level design and present corresponding estimators based on the infinite population approach in the first phase. After stratification of the sample points (phase I), a second-phase sample is drawn independently among the first-phase points within… (More)
To meet the demand for sustainable forest management, especially in terms of climate change and subsequent risks, planning and decision-making becomes increasingly important (Pretzsch et al. 2008). Simulation models support forest planning since they allow studying future scenarios thus facilitating the decision-making process. Within the scope of the… (More)