Morpho-ecological Characteristics of an Invasive Vine (<i>Thunbergia grandiflora Roxb</i>.) to Varying Light Intensities in Mt. Makiling Forest Reserve, Los Baňos, Philippines

Abstract

Invasive species represent the second most remarkable cause of extinction worldwide after habitat destruction (IUCN, 2011). Skyflower (Thunbergia grandiflora Roxb.) that is slowly invading Mt. Makiling Forest Reserve (MMFR) was subjected to varying light intensities. Morpho-ecological characters were evaluated using Analysis of Variance for Randomized Complete Block Design. Bonferonni’s method at 5% level of significance was used for mean comparison. Plant height, number of leaves and nodes were higher in 0% (open condition) and 50% (partial shade) compared to those grown in 70% (complete shade). There was no significant difference (P>0.05) in stem thickness, biomass, and chlorophyll content in all treatments. Leaf area was smallest in plants grown in the open condition. There was significant difference between the two locations (greenhouse and field) for the number of nodes, number of leaves, and stem thickness (P<0.05). Skyflower has strong morphological plasticity in open and partially shaded areas but can also thrive in areas with low light intensity. It is capable of smothering canopies and continues to spread on the lower slopes of MMFR. An Aspect Map generated from a Digital Elevation Model in ArcGIS can be used to distinguish sites with minimum or maximum sun exposure and serve as a useful tool to identify priority areas for the extirpation of Skyflower in MMFR, Luzon, Philippines.