Data from: Harvesting has variable effects on demographic rates and population growth across three dry forest tree species
Data files
Jul 20, 2022 version files 19.76 KB
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Demogdata.csv
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README.txt
Abstract
Understanding how anthropogenic activities, such as harvesting, influence plant populations is important to quantify sustainable practices that conserve species of socioeconomic importance. There is limited knowledge on how harvesting of branches and non-timber forest products affect populations of trees in the dry tropics. We measure demographic vital rates of three dry tropical tree species in the presence and absence of harvesting and apply integral projection models to quantify population growth rates, which represent the mean fitness across the life cycle. Our results show that the three species vary in their demographic rates and life history. Harvesting significantly decreases the growth of two species. Current levels of harvesting only significantly decreased the population growth rate of one species that experienced both branch and main stem harvesting. Life table response experiments reveal that the negative effect of harvesting on the population growth rate of this species is primarily due to individuals being forced to re-sprout from their base. Few individuals were observed recruiting from seed, and this might be due to the presence of other threats, such as fire, soil erosion, and grazing. Our results provide knowledge on the demography and the effects of harvesting on endemic tree species of the Eastern Ghats, a region for which few demographic studies are available. These results are relevant to conserving forest biodiversity for the benefits of people and can contribute to quantitative threat assessment for IUCN red listing.
Methods
Demographic data was collected in two census years 2009 and 2016. During both censuses, girth at breast height or collar girth was measured for each individual. Girth was converted to diameter for analysis. This file contains information of plant sizes (diameter), survival, transition of tree to sprout and presence of harvesting for individuals of Acacia chundra, Chloroxylon swietenia and Gardenia gummifera.