How landscape modulators function: woody plant impact on seed dispersal and abiotic filtering |
| |
Authors: | O Gabay A Perevolotsky M Shachak |
| |
Institution: | (1) Blaustein Institutes for Desert Research, Ben-Gurion University, 84990 Midreshet Sede-Boqer, Israel;(2) Department of Agronomy and Natural Resources, Agricultural Research Organization, 50250 Bet Dagan, Israel |
| |
Abstract: | The Mediterranean landscape is characterized by a heterogeneous structure: a mosaic of woody plants (trees or shrubs) with
scattered patches of herbaceous vegetation. Although the herbaceous and woody patches are adjacent to each other, plant species
composition in them is substantially different. This could be attributed to either differences in environmental conditions
between patch types (i.e., abiotic filters), or to dispersal limitations caused by the woody plants acting as dispersal filters.
In this article, we focus on the relative impact of woody plants, applying these two filter types, in determining plant species
composition in Mediterranean woodland. We experimentally manipulated shade and litter cover and examined the effect of each
of these factors on plant species composition. We used seed-traps to evaluate seed arrival in the patches, and experimentally
removed the shrub canopy to study the effect of the shrub as a physical barrier to seed entry. Results showed that plant species
number and composition were not significantly affected by shade and litter manipulation. The number of trapped seeds were
significantly higher in the open patches than in the woody patches, and removal of woody plants increased the number of trapped
seeds in both open and woody patches, as a result of eliminating the physical obstacle to free seed movement. Our findings
show that woody plants affect the herbaceous plant community by influencing seed dispersal, and highlight that they affect
other organisms not only by modifying resource availability but also through the creation of a new landscape structure. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|