Identifying Framework Tree Species for Restoring Forest Eco-System in Siem Reap Province
Sobon, K. 2013. Identifying framework tree species for restoring forest eco-system in Siem Reap Province. Graduate School, Royal University of Agriculture, Cambodia.
ABSTRACT: Deforestation and forest degradation are major concerns in Cambodia. Therefore, scientists must find new ways to restore degraded forest and/or forest ecosystem. The study, reported here identified framework tree species for restoring forest eco-systems in Siem Reap Province. It compared field performance among indigenous tree species, determined the degree to which each species met framework criteria and established appropriated standards for selecting framework tree species for restoring forest ecosystem.
The research was conducted at the Forest Restoration and Extension Station in Kulen Mountain Buffer Zone, FORRU-Cambodia’s project site. Experimental field plots were established in 2010 and 2011. Vegetation surveys and soil sample analysis were conducted, before candidate framework tree species were planted and monitored for survival growth and response to fertilizer. Data analysis was carried out by MS Excel to analyze relative growth rates and SPSS 19.0 for ANOVA analysis.
Sixteen of the 19 species tested were considered suitable for planting to restore forest ecosystems in the northern part of the Siem Reap Province. Seven of the 16 had high field performance, with survival rates exceeding 70% after 18 months: Gardenia sootepensis Hutch, Canarium subulatum Guill, Dalbergia cochinchinensis Pierre, Hopea odorata Roxb, Xylia xylocarpa (Roxb.), Sindora siamensis Teysm. ex Miq.var. Siamensis, and Sindora siamensis Teysm .ex Miq.var. cochinchinensis. Nine other had medium field performance, with survival rates of 50-69%, but broad crowns and also scored as acceptable for planting for restoring forest ecosystem: Afzelia xylocarpa (Kurz) Craib, Knema globularia (Lam.) Warb, Diospyros sylvatica Roxb, Diospyros ehretioides Wall.ex G.Don, Cratoxlum cohcinchinenesis, Gardenia angkorensisi, Walsura trichostemon Miq, Dioecrescis erythroclada (Kurz) Tirv and Hydnocarpus anthelmintica Pierre ex Lanes.
In experimental plots 2010; Buffalo fertilizer (15-15-15) and organic fertilizer (10-5-2) significantly increased seedling survival rates. However, survival rates were not significantly different among species. One hundred grams of Buffalo fertilizer increased seedling survival more than 50g buffalo fertilizer and/or Taiwan organic fertilizer. Interactions between fertilizer treatments and species were not significant, indicating that differences among tree species were not affected by fertilizers. Fertilizer treatments significantly affected root caller diameter growth. In experimental plots 2011; Buffalo chemical fertilizer (16-16-8) and organic fertilizer (3-3-2) significantly increased seedling survival and contributed to significant differences among tree species. Fifty grams of buffalo fertilizer had a great effect on seedling survival than 100g buffalo fertilizer and organic fertilizer. However, interactions between fertilizer treatments and height and root caller diameter growth were not significant.
This research will be valuable for forest restoration programmes in Cambodia, and for the agencies that implement them: both the governments Forestry Administration of the Ministry of Agriculture, Forestry and Fisheries, Ministry of Environment and NGO’s. It provides basic information to assist with decision making on species choices for the Siem Reap area and on experimental techniques to enable selection of species based on logical criteria for other areas.