TITLE:
Responses of Native Tree Species to Soil Water Stress in a Tropical Forest on Limestone, Vietnam
AUTHORS:
Le Van Binh, Nguyen Van Thinh, Reinhard Köpp, Vo Dai Hai, Ralph Mitlöhner
KEYWORDS:
Tropical Limestone Forests, Floristic Composition, Native Tree Species, Leaf Water Potential, Leaf Osmotic Potential
JOURNAL NAME:
Open Journal of Forestry,
Vol.5 No.7,
September
30,
2015
ABSTRACT: Forests
over limestone in the tropics have received little attention and limestone
forests in Vietnam have been overlooked to an even greater extent in terms of
tree physiology. In Ba Be National Park, Vietnam, soil water availability in
limestone forests seems to be the most limiting factor in the dry season.
Therefore, in order to enhance the preliminary knowledge of choosing native
tree species for enrichment planting in the restoration zone, characteristics
of the 20 native tree species to soil water stress were investigated in a
limestone forest. One-ha plot each consisting of twenty-five 20 m × 20 m plots
was established in undisturbed forests. All trees ≥ 10 cm DBH were measured in
20 m × 20 m plots, while twenty-five 5 m × 5 m subplots were established in
order to sample the regeneration of tree species with a DBH w)
and leaf osmotic potential (Ψπ)
of the 20 native tree species, respectively in this study. 61 species belonging
to 34 families of all trees with a DBH ≥ 10 cm were recorded in one ha, while
31 species representing 18 families of trees 2. The 20 species’ leaf water and osmotic potential values
revealed significant differences among species. The maximum leaf water
potential was not affected by any anticipated sources of variation, while the
minimum water potential, however, showed significant variation to soil water
stress. The results in the study area emphasized the importance of water
factors in influencing tree species distribution; it could be concluded that
native species with wide water potential ranges would be better able to
withstand water changes and might be thus good candidates for reforestation
(enrichment planting) in limestone areas.