Short Communication: Incidence of insect pest on planted Shorea macrophylla at reforestation sites in Gunung Apeng National Park, Sarawak, Malaysia

Sidi MB, Wasli ME, Polly E, Jaffar ANNM, Kalu M, Sani H, Nahrawi H, Elias H, Omar D. 2021. Short Communication: Incidence of insect pest on planted Shorea macrophylla at reforestation sites in Gunung Apeng National Park, Sarawak, Malaysia. Biodiversitas 22: 5162-5168. Incidence of insect pest in Shorea macrophylla (de Vriese) P.S. Ashton had critical foliage damage in mono planting technique. The main objectives were to assess the foliage damage intensity of planted S. macrophylla by age stands and type of foliage damage. The insect pest attacks the foliage of S. macrophylla was determined. The study site was located at Gunung Apeng National Park (GANP), Sarawak, Malaysia, with planted S. macrophylla in enrichment planting at different years (planted in 2008, 2009, 2010, and 2011 for age stand 6, 5, 4, and 3, respectively). The results showed that the degree of foliage damage decreases with the age stand of S. macrophylla tree. Therefore, foliage damage was suspected to be caused by insect pests. Among the common foliage damages observed was "hole damage" caused by insect order Lepidoptera. Although foliage damage was significant, the severity of the damage will "heal" as the age stand increases. Further investigation on other possible causes of these pest attacks should be initiated to find solutions that may hasten the growth of planted S. macrophylla for forest restoration.

A 17 Year Successional Enrichment Plantation of Tree Recruitment and Restoration in an African Tropical Forest

Key message: The Enrichment Plantation of Akure Forest Reserve is one of the forests currently experiencing a 17-year-long post-disturbance following deforestation and fragmentation in Nigeria. Context: To better understand the contribution of enrichment planting on forest regeneration and restoration, when the Enrichment Plantation after 17 years of post-disturbance was examined. Aims: We studied the recruitment drive of aboveground and undergrowth stands of an Enrichment Plantation in the tropical forest reserve. We assess the trees diversity, species compositions, species richness, and growth forms of the vegetations. Methods: A total of 3(50m x50m) plots were sampled. A total of 47 aboveground tree species and 45 undergrowth stands from Enrichment Plantation were identified. A statistical analysis were used to quantified the data obtained from this resultsResults: The result shows an increase in the diversity and an even distribution of the species of the aboveground forest trees, compared to the undergrowth stands. Conversely, the aboveground forest trees have lower species richness as compared to the level of undergrowth stands. The sapling density was significantly higher than the aboveground tree of the. It was also observed that the aboveground forest trees and undergrowth stands are somewhat similar in species compositions, which implies that sapling recruitment is a key determinant of the tree species composition of the forest.Conclusion: It is then concluded that the method adopted for restoration encouraged species diversity in this successional forest among the aboveground trees species and undergrowth.

Tabebuia rosea (pink poui).

T. rosea is a medium to large tree attaining a height of 28-37 m with a d.b.h. of 50-100 cm. It is widespread from Mexico to Peru, Venezuela and Ecuador. T. rosea is a very important species in these regions, its timber is valuable and of good quality, it is excellent to work and has an attractive finish. It shows good performance in forestry plantations and enrichment planting trials, and also has high potential to be used in afforestation projects. This species is also used in agroforestry (e.g. alley cropping), as a live fence, as a shade tree and as an ornamental. It is the national tree of El Salvador.

Greenhouse gas fluxes from an oil palm plantation on mineral soil in Indonesia undergoing riparian restoration

<p>Oil palm (OP) growers are under pressure to reduce their environmental impact. Ecosystem function and biodiversity are at the forefront of the issue, but what effect do changes in management practices have on greenhouse gas (GHG) fluxes from plantations? </p><p>The Riparian Ecosystem Restoration in Tropical Agriculture (RERTA) Project is a collaboration between the University of Cambridge and the SMART Research Institute in Riau, Indonesia. This project explores the ecological changes resulting from the restoration of riparian margins between plantations and watercourses. Four management strategies were applied on both sides of a river to create 50m riparian buffers, 400m in length: (1) A control treatment of no restoration, the removal of mature OP and replanting of young OP to the river margin; (2) Little to no agricultural management of mature OP; (3) Clearance of mature OP and enrichment planting with native forest trees; (4) Little or no agricultural management of mature OP and enrichment planting with native forest trees. Here we present a specific objective to investigate the effect of riparian restoration – and related changes in soil characteristics, structure and vegetation cover – on fluxes of N<sub>2</sub>O, CH<sub>4</sub> and CO<sub>2</sub> from mineral soils.</p><p>The experimental site began as a mature OP plantation, with monthly background measurements taken between January and April 2019. Palms were felled in April 2019 and monthly sampling was resumed when replanting and restoration began, in October 2019. We measured GHGs using static chambers; 6 in each riparian treatment and 16 in the actual OP plantation, 40 chambers in total. Samples were analysed using GC-FID/µECD.</p><p>Background measurements before felling showed high variability, but indicated no difference between the four experimental plots and the rest of the plantation. Fluxes measured following replanting were also highly variable, with no significant differences observed between treatments. N<sub>2</sub>O fluxes were relatively low before felling as the mature palms were no longer fertilised. Higher emissions were seen in the disturbed immature OP and forest tree treatments following replanting. Though the sites appeared to recover quickly and emission fluxes decreased after a few months, presumably as the soil settled and new vegetation began to grow. CH<sub>4</sub> uptake was seen in the immature OP treatment immediately after replanting. In subsequent months no clear trends of CH<sub>4</sub> uptake or emission were observed, with the greatest variability generally seen in the forest tree treatment. CH<sub>4</sub> emissions increased in October 2020 with the beginning of the rainy season, most notably in mature OP and mature OP with forest tree treatments. Following restoration CO<sub>2</sub> emissions were higher in treatments with established plant communities – mature OP and mature OP with forest trees.</p><p>These results suggest that riparian restoration had no significant effect on GHG fluxes from mineral soils, and would not alter the overall GHG budget of a plantation. If there is no additional GHG burden and riparian restoration results in enhancing biodiversity and ecosystem services as well as improving water quality, it will be a viable management option to improve the environmental impact of an OP plantation.</p>

Restoration of Water Storage Potential in a Degraded Dry Dipterocarp Forest with Enrichment Planting of Three Needle Pine (Pinus kesiya Royle ex Gordon), Northern Thailand

The research assessed water storage in a dry dipterocarp forest (DDF) with enriched 34-year-old pine planting and the role of pine. Plant surveys were carried out using 10, 40×40 m2 plots, and data were obtained by measuring tree stem girths and heights. Plant features, biomass, and stored water amounts were measured. Fresh plant samples of abundant species were taken one time per month from January to December 2018. Three soil pits were made in three plots, and soil samples along 100 cm depth were taken on the same days of collecting plant samples for studying fied capacity, water content and water amount. The DDF was divided into three stands based on the most dominant tree species; Shorea obtusa, Dipterocarpus tuberculatus, and Dipterocarpus obtusifolius. The forest was composed of 86 species with biomass at 101.62 Mg/ha and contained an average water amount of 88.01 m3/ha. The water amount in biomass varied with sampling times from 58.74 to 111.83 m3/ha. The average MWHC of 100 cm soil was estimated to be 5,113.74 m3/ha. The water amount in soil also varied with sampling times from 3,651.50 to 4,481.06 m3/ha. As a result, the total water amount in plant biomass and soil (ecosystem) of the DDF varied in a range from 3,735.0 to 4,558.67 m3/ha. The pine contributed to 30.87 m3/ha (35.07% of the total) and could increase by 64.92% the water storage potential of the forest, and thus these results support the concept of pine enrichment planting in the poor DDF.