Diversity and richness of exotic weeds in fruit tree orchards in relation to irrigation managment

摘要

Irrigated fruit tree orchards are environments rich in associated weed flora. Presence of water favours installation of exotic plants because these systems do not exhibit the characteristic summer drought of Mediterranean areas. Two different irrigation systems can be distinguished: traditional flood irrigation and modern drip irrigation. Moreover, weed control management carried out under the tree rows is different to that made in the inter-rows. We compiled a data set of 900 vegetation plots of weed vegetation in inter-rows and under the tree rows of flood irrigated and drip irrigated fruit tree orchards. In order to test possible effects of irrigation system and weed control management on richness and diversity of weed community, both native andexotic, two-way ANOVA was performed. Results show that flood irrigation systems favour richness and diversity of exotic plants while drip irrigation systems favour native plants. Presence of both native and exotic plants are larger in the inter-rows thanunder the trees