Evaluating the Intraspecific Interactions of Indian Rosewood (Dalbergia sissoo Roxb.) Trees in Indian Rosewood Reserveof Khuzestan Province

Abstract

Positive and negative (facilitative and competitive) interactions of plants are important issues in autecology and can be evaluated by the spatial pattern analysis in plant ecosystems. This study investigates the intraspecific interactions of Indian rosewood (Dalbergia sissoo Roxb.) trees in Indian rosewood Reserve of Khuzestan province. Three 150 m × 200 m plots were selected and the spatial locations of all Indian rosewoods (239 trees) were specified. Structurally different summary statistics (nearest neighbour distribution function D(r), K2-index K2(r), pair correlation function g(r), and O-ring O(r)) were also implemented to analyze the spatial pattern of the trees. The distribution of Indian rosewood trees significantly followed inhomogeneous Poisson process (α=0.05). The results of D(r) and K2(r) showed that the maximum distance to nearest tree was 12 m and density was decreased to this scale. The results of g(r) and O(r) also revealed the significant aggregation of Indian rosewood trees at scales of 1.5 to 4 m (α=0.05). In general, it was concluded that Indian rosewood trees had positive intraspecific interactions in Indian rosewood Reserve of Khuzestan province and their aggregation showed their facilitative effects on one another.

Keywords

• Facilitation
• Spatial pattern analysis
• Khuzestan
• Indian rosewood
• Interaction.