Survivorship and Growth Performance of <i>Shorea macrophylla</i> (de Vriese) after Enrichment Planting for Reforestation Purpose at Sarawak, Malaysia

Abstract

Reforestation may offer one means of mitigating the processes of forest land degradation and is indispensable in an effort to conserve forest biological diversity in the tropics. Thus, a preliminary assessment was conducted in order to evaluate the survivorship and growth performance of Shorea macrophylla (de Vriese) after enrichment planting for reforestation purpose in Sarawak, Malaysia. This study was conducted at reforestation sites located at Sampadi Forest Reserve, Sarawak, Malaysia where indigenous Dipterocarp species, S. macrophylla (de Vriese) were planted by line planting system. Study sites were established at reforestation areas at different age stands; (planted in the year 1996; SM96, 1997; SM97, 1998; SM98 and 1999; SM99). The assessment on the growth performance of planted S. macrophylla was evaluated by measuring the trees total height, Diameter at Breast Height (DBH) and calculation of the percentage of survival. The findings indicated a positive tree growth in terms of growth performance and survival which clarified the efficacy of line planting technique adapted in the studied sites. Growth performance in terms of survivability; Mean Annual Increment of Height (MAIH) and Diameter (MAID) in SM96 revealed the highest growth rate as compared to SM97, SM98 and SM99. For the average tree height and diameter at breast height, the results showed that the tree height and diameter in SM96 were 11.8 m and 14.7 cm, respectively. Meanwhile, SM99 recorded the lowest average tree height and diameter reading with 8.8 m and 6.6 cm, respectively. Nonetheless, high survival percentage of S. macrophylla were depicted in this study with 89% of survival in SM96, followed by 80, 82 and 57% in SM97, SM98 and SM99, respectively. Substantial growth performance and high survival percentage of S. macrophylla implied that microclimate condition such as competition between planted and existing pioneer species of the study sites may have affected the tree growth performance of the planted S. macrophylla. Notwithstanding, further studies are essential in order to find out the plant-soil association of S. macrophylla where other environmental factors may affect the growth and survival of the planted species.

Association between Soil Fertility and Growth Performance of Planted Shorea macrophylla (de Vriese) after Enrichment Planting at Rehabilitation Sites of Sampadi Forest Reserve, Sarawak, Malaysia

“…A brief summary of the relationship between PC1 score, SFI, SEF, and tree growth parameters (diameter at breast height (DBH) and height) and percentage of survival was shown in Table 4. Notwithstanding, to predict the best indicator for estimating soil fertility and site quality in relation to survivorship and growth performance of planted Shorea macrophylla after enrichment planting, the values of soil available phosphorus content at the rehabilitation sites at both surface and subsurface soil depths were correlated with tree growth parameters (diameter at breast height (DBH) and height) and survival from our previous study [18]. The results indicated that there was a strong relationship between the soil available phosphorus and tree growth parameters: diameter at breast height, height, and percentage of survival as shown in Figure 6.…”

“…Nonetheless, in order to determine the applicability of these indices for estimating soil fertility and site quality in relation to survivorship and growth performance of planted Shorea macrophylla after enrichment planting, the values of the PC1 score, SFI, and SEF at both surface and subsurface soil depths were further correlated with the tree growth parameters (diameter at breast height (DBH) and height) and survival of the planted Shorea macrophylla trees from our previous study [18]. The results revealed positive and moderate correlations between the PC1 score and diameter at breast height (DBH) and survival percentage at surface soils ( = 0.546 * * , P < 0.01 and = 0.477 * , P < 0.05, resp.)…”

“…According to our previous study [18,19], high content of available phosphorus in soils was related to an increase in the growth and survival percentage of S. macrophylla in SM96 and SM97, whereas the low content of available phosphorus was related to a decrease in the growth and survival percentage of the planted trees in the SM98 and : Relationship between soil available phosphorus with diameter at breast height (DBH), height, and percentage of survival derived from surface and subsurface soils. * , * * Correlations are significant at 5% and 1% levels, respectively, using Pearson correlation matrix.…”

“…The riparian forest along the major rivers or streams had lost their original forms and structure through shifting agriculture or past logging activities. The preparation of sites prior to the plantation establishment and planting technique used were mentioned and explained in the previous study [18,28]. The planted species in the study area were mainly from Dipterocarpaceae family such as Engkabang jantong (Shorea macrophylla), Meranti sarang punai (Shorea parvifolia), Selangan batu (Shorea falcifera), Kapur bukit (Dryobalanops beccarii), and Bintangor bukit (Calophyllum alboramulum).…”

“…Rehabilitation efforts in degraded forestland due to abandoned shifting cultivation have been successfully implemented under the ecosystem rehabilitation [16] and by enrichment planting technique [17,18] in Sarawak, Malaysia. In Sarawak, one of the common indigenous tree species from Dipterocarpaceae family, Shorea macrophylla (de Vriese), was considered and selected for forest rehabilitation purposes [18,19]. This climax species was chosen since it is one of the fastest growing species of the genus Shorea and is found frequently along rivers and in areas which are periodically inundated.…”