Habitat associations of select tree species in a tropical rainforest in San Mateo, Rizal

Abstract

The Sierra Madre mountain range is one of the regions in the Philippines facing rapid decline in forest cover, increasing the need for conservation efforts. A key aid in these efforts is the use of multivariate analyses to determine associations between species and their habitat. Among them is Canonical Correspondence Analysis, which was performed here on selected tree species in a secondary forest in San Mateo, Rizal. A vegetation survey was conducted and selected edaphic and habitat variables were measured on three study areas. Sixty-two tree species, belonging to 23 families, were identified. Two ordination diagrams were produced, and the first two canonical axes of each are the following: (1) soil pH and soil texture, (2) forest quality and elevation. From the axes of soil texture and forest quality, niche widths were determined and analyzed, revealing ranges of the species’ preference and tolerance. Species survival envelopes were generated to summarize species’ niche positions, indicating habitat preferences, and niche widths, indicating ranges of tolerance, across soil texture and forest quality. This information has strong implications for forest management, and can help stakeholders in the formation of strong science-based conservation plans.