Plant β-diversity in human-altered forest ecosystems: the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages

Abstract

An understanding of spatial patterns of plant species diversity and the factors that 2 drive those patterns is critical for the development of appropriate biodiversity 3 management in forest ecosystems. We studied the spatial organization of plants species in human-modified and managed oak forests (primarily, Quercus faginea) in 5 the Central Pre-Pyrenees, Spain. To test whether plant community assemblages 6 varied non-randomly across the spatial scales, we used multiplicative diversity 7 partitioning based on a nested hierarchical design of three increasingly coarser 8 spatial scales (transect, stand, region). To quantify the importance of the structural, 9 spatial, and topographical characteristics of stands in patterning plant species 10 assemblages and identify the determinants of plant diversity patterns, we used 11 canonical ordination. We observed a high contribution of -diversity to total -12 Maintaining habitat heterogeneity at multiple spatial scales should be considered in 1 the development of management plans for enhancing plant diversity and related 2 functions in human-altered forests.

Woody Species Composition in Relation to Spatial and Environmental Gradients in Acacia-Commiphora Vegetation Ecosystem of Ethiopia

“…Despite there is high diversity of vegetation ecosystems in the tropical regions our understanding of the spatial pattern and extent of change in species composition is poor [12]. In other regions, the dissimilarity in species composition across spatial and environmental gradients was shown by previous studies [1,6]). In tropical regions, most of the previous studies were limited to the local scales or case studies and less is understood across scales [13].…”

“…Understanding the factors driving the spatial patterns of species composition is critically important in conservation planning [1,2]. However, since vegetation is not spatially uniformly distributed, it is a challenge but also a major task in community ecology to understand such heterogeneity [3].…”

Patterns of the Diversity of Characteristic Species Across Vegetation Ecosystems of Ethiopia

“…Understanding the spatial patterns of species distribution is one of the major components in conservation planning mainly under the currently prevailing climate change [1][2][3][4]. With this respect, some areas are comprised of enormous diversity, the other extreme areas are devoid of vegetation while most lie in between teemed with intermediate species diversity [5].…”

“…Even though the vegetation is heterogeneously distributed across spatial scales and environmental gradients [5,4,7,2], most of the previous studies undertaken on vegetation ecosystems so far have focused on the diversity of a certain locality or site mainly in understudied tropical regions [8,9]. For example, in Ethiopia, many of the earlier studies described vegetation structure only at local scale and lack explorations across spatial scales [10][11][12][13][14][15].…”

“…However, following similar approach, [17] has recently revised the previous classifications into the following 12 major ecosystem types. (1) Afroalpine belt (AA): is found in areas of highest mountains that peak approximately above an altitude of 3200 m a. s. l., (2) Ericaceous belt (EB): is found adjacent to Afroalpine belt ecosystem in most of the higher mountains in Ethiopia between the altitudinal range of 3000-3200m a. s. l., (3) Transitional rain forest ecosystem (TRF): is found adjacent to Moist evergreen Afromontane forest ecosystem in southwest Ethiopia, (4) Moist evergreen Afromontane forest (MAF): is characterized by closed strata that may reach to the height of 30 to 40m and where wild coffee is found within the altitudinal range of between 1500-3000m a. s. l. and in areas receiving an annual rainfall between 700-2000mm, (5) Dry evergreen Afromontane forest and grassland complex (DAF): this represents the largest and complex ecosystem in Ethiopia and found in different regions of the country between the altitudes of 1800-3000m, (6) Combretum-Terminalia woodland and wooded grassland (CTW): comprises fairly large sized deciduous trees and grasses and is widely found in lowland areas and western escarpments of Ethiopia, (7) Wooded grassland of the western Gambela region (WGG): is characterized by a tall grass stratum, herbaceous flora, grass species and different acacia species, (8) Acacia-Commiphora woodland bushland (ACB): is found in dry lowland areas of eastern, southern part of Ethiopia and to the east of the highlands in the Rift Valley, (9) Desert and semi-desert scrubland (DSS): here the vegetation cover is scarce and comprises mainly drought tolerant species. Some areas are bare, for example, the salt pans in the Danakil depression lying below 400m a. s. l. altitude in eastern Ethiopia, (10) Riverine vegetation (RV): big rivers and their tributaries form the drainage systems and in areas where altitude is approximately below 1800m a. s. l. these rivers have riverine forests, (11) Freshwater lakes, lake shores, marsh and floodplain (FLV): the major fresh water lakes include Lake Tana, Lake Ashange, Lake Langano, Lake Ziway, Lake Awasa, Lake Abaya and Chamo and Turkana and (12) Salt lakes, salt-lake shores, marsh and pan vegetation (SLV): is represented by salt tolerant species.…”