Undergrowth

About: Undergrowth is a research topic. Over the lifetime, 795 publications have been published within this topic receiving 11911 citations. The topic is also known as: understorey & underbrush.

Wild coffee management and plant diversity in the montane rainforest of southwestern Ethiopia.

Abstract: Coffea arabica occurs naturally in the montane rainforests of Ethiopia, but large areas of these unique forests have been converted to other land-uses. In the remaining forest, wild coffee is managed and harvested with increasing intensity because of rising coffee prices in the world market. This study evaluated the impact of coffee management on wild coffee populations and the forest vegetation as a basis for conservation planning in southwestern Ethiopia. Vegetation surveys and yield assessments were carried out in unmanaged natural forest and in managed semi-forest coffee (SFC) systems. Analyses show that wild coffee density and coffee yields were low in natural forest (max. 15 kg ha )1 year )1 ). In SFC systems, 30% of the canopy trees and most undergrowth vegetation were removed. This stimulated wild coffee growth and strongly enhanced yields (max. 54 kg ha )1 year )1 ), but severely disturbed forest structure. Species richness increased by 26% because of an increase in species of ruderal and secondary vegetation; however, species richness and abundance of typical forest species declined. Conservation of the natural forest therefore requires the control of wild coffee management. Wild coffee certification is discussed as one tool to reconcile conservation measures and the interests of local farmers.

Changes in Ponderosa Pine Bunchgrass Ranges in Northern Arizona Resulting from Pine Regeneration and Grazing

Abstract: open than they are today. Present forest conditions contrast strikingly with early photographic records and descriptions (4). A deficient undergrowth of seedling and sapling pines was reported in the forest surveys of 1901-1902 and as a consequence the forest floor was more fully occupied by herbaceous species. This may explain in part why early estimates of livestock greatly exceeded present numbers. At the turn of the century, the inadequate regeneration of ponderosa pine caused grave concern among southwestern foresters (7, 8). The acute problem of natural reforestation was greatly relieved when, in 1919, an unusual distribution'.of moisture favored the suc-

Providing Habitat for Native Mammals through Understory Enhancement in Forestry Plantations

Abstract: The Convention on Biological Diversity (CBD) expects forestry plantations to contribute to biodi- versity conservation. A well-developed understory in forestry plantations might serve as a surrogate habitat for native species and mitigate the negative effect of plantations on species richness. We experimentally tested this hypothesis by removing the understory in Monterey pine (Pinus radiata) plantations in central Chile and assessing changes in species richness and abundance of medium-sized mammals. Frequency of occurrence of mammals, including kodkods (Leopardus guigna), culpeo foxes (Pseudalopex culpaeus), lesser grisons (Conepatus chinga), and Southern pudu deer (Pudu puda), was low in forest stands with little to no understory relative to stands with well-developed undergrowth vegetation. After removing the understory, their frequency of occurrence decreased significantly, whereas in control stands, where understory was not removed, their frequency did not change. This result strongly supports the idea that facilitating the development of undergrowth vegetation may turn forestry stands into secondary habitats as opposed to their containing no habitat for native mammals. This forestry practice could contribute to conservation of biological diversity as it pertains to CBD targets.

The influence and comparison of individual forest trees on soil properties and possible inhibition of nitrification due to intact vegetation

Abstract: A B S T R A C T Soil properties were found to vary with increasing distance from tree trunks of individuals of the same species, and different species were found to vary in their effects on soil properties. The differences in pH and mineral concentration at different distances from the trunk were often statistically significant even under the same tree. When all species are considered, iron had the least variability at different distances from the trunks of all minerals investigated, followed by potassium. Nitrate nitrogen had the greatest overall variability at different distances from the trunks. Ammonium nitrogen in the soil was always considerably higher than nitrate nitrogen when compared at each distance from the trunk under each species. Low amounts of nitrate nitrogen could not have been due to its uptake by the intact vegetation, because the soil samples were taken before the active growth period. It seems possible that the variable tree litter under different species plays an important role in controlling the soil pH, nitrification, and mineralization. Thus, it appears that in a climax community different dominating species, by developing variable physio-ecological niches, can determine the variable undergrowth vegetation under them.