Nugroho Y, Soendjoto MA, Suyanto, Matatula J, Alam S, Wirabuana PYAP. 2021. Traditional medicinal plants and their utilization by local communities around Lambung Mangkurat Education Forests, South Kalimantan, Indonesia. Biodiversitas 23: 306-314. Lambung Mangkurat Education Forests (LMEF) is a unique forest area with high plant diversity, including medicinal plants. This study aimed to document the list of natural medicinal plant species in LMEF and analyze the community perceptions on utilizing them. Exploratory surveys collected data through field observation and interviews with people living in villages around LMEF. The inventory of medicinal plants was conducted by line transect method with 1,000 m long and 20 m wide. Meanwhile, indigenous communities' description of medicinal plant utilization was explored using an interview process on fifty respondents. The results showed that 56 medicinal plant species were naturally distributed in LMEF. Most plants have habitus as trees, wherein local communities commonly use their leaves as traditional medicine. Local people generally applied the extraction process using hot water to obtain the benefit of these plants. Interestingly, more than 70% of respondents prefer traditional medicine to drugs. These findings indicated that the sustainable management of LMEF can support the vital role of forest ecosystems for people's health.

Nugroho Y, Suyanto, Makinudin D, Aditia S, Yulimasita DD, Afandi AY, Harahap MM, Matatula J, Wirabuana PYAP. 2022. Vegetation diversity, structure and composition of three forest ecosystems in Angsana coastal area, South Kalimantan, Indonesia. Biodiversitas 23: 2640-2647. Vegetation communities around coastal ecosystems play important roles in mitigating natural disaster and climate change. However, available information about vegetation communities in coastal areas is still limited despite being a requirement in developing strategies for environmental preservation. Angsana coastal area in South Kalimantan, Indonesia has unique characteristics in which it has three different forest ecosystems, namely heath forest (HF), beach forest (BF), and mangrove forest (MF). This study aimed to identify the vegetation diversity, structure and composition of the three forest ecosystems in Angsana coastal area. A field survey was conducted using transect line methods with a sampling plot size of 10 × 10 m and an interval of 20 m. Vegetation communities were assessed using species abundance, plant diversity, importance value index (IVI), and similarity level. Results showed that 37 species from 25 families were recorded at the study site. The highest species abundance was observed in HF (22 species), followed by BF (18 species) and MF (7 species). The same trend was found for vegetation diversity, in which HF had the highest richness (Dmg = 4.52), heterogeneity (H' = 2.86), and evenness (J' = 0.94). Hibiscus tiliaceus L. had the highest IVI in BF in all vegetation stages, and Rhizophora mucronata Lam. consistently had the greatest IVI in MF in all stages. Species thet exhibited the highest IVI in HF were Adina minutiflora Valeton (seedlings), Rhodedomia tomentosa and Premna serratifolia L. (saplings), Tristania maingayi Duthie (poles), and Vitex ovata Thunb. (trees). Our study also observed that species abundance in forest ecosystems gradually declined from seedlings to trees, except in MF. Among the three forest types, vegetation composition was highly similar between MF and BF, with a similarity level of 47.1%. Based on these results, this study concluded that the three forest ecosystems in Angsana coastal area exhibit a highly diverse vegetation structure, and each type of forest has specific characteristics as its entity.

Clonal teak plantation has been extensively developed in Java and providing a purposeful contribution to improve the productivity of the state forests. It also plays a crucial role in climate change mitigation and serves as a primary source of renewable energy. However, information about its stand dynamics has been rarely documented. This study investigated the growth, biomass, carbon stock, and energy storage along an age series of clonal teak plantation. The study site was located in the Kendal Forest Management Unit. Data were collected from 14 different compartments as the priority sites of clonal teak establishment. Every compartment had similar site quality but different in age stand. Results demonstrated that the incremental rate of diameter and height was higher during the initial period between 1 and 3 years. The mean volume increased along with age and reached its maximum value at 14 years (164.54 m³ ha⁻¹). Biomass distribution in each tree component varied from 8.75 to 66.72%. More than 80% biomass production was accumulated above ground. Total carbon stock improved from 2.68 Mg ha⁻¹ at 1 year to 54.01 Mg ha⁻¹ at 14 years. Our study noted that the total energy storage in clonal teak plantation increased progressively from 22.71 × 106 MJ ha⁻¹ at 1 year to 377.74 × 106 MJ ha⁻¹ at 14 years. Overall, this study concluded the growth, biomass, carbon, and energy in clonal teak increased progressively with age. Further investigations are still required to understand the stand dynamics of clonal teak at different sites.

Suyanto, Nugroho Y, Harahap MM, Kusumaningrum L, Wirabuana PYAP. 2022. Spatial distribution of vegetation diversity, timber production, and carbon storage in secondary tropical rainforest at South Kalimantan, Indonesia. Biodiversitas 23: 6147-6154. Sustainable management in secondary tropical rainforests requires basic information about stand characteristics, mainly related to productivity and biodiversity. This study aimed to quantify vegetation diversity, timber production, and carbon storage from various sites of secondary forests in South Kalimantan. Forest inventory was conducted using a census method at seven different natural forest management unit compartments. Four parameters were measured from each tree, including the type of species, commercial categories, tree diameter, and tree height. Individual tree volume and biomass were estimated using allometric equations, while carbon storage was determined using a conversion factor from biomass. Three indicators were used to evaluate vegetation diversity: richness, heterogeneity, and evenness. The analysis of correlations was applied to examine the relationship between vegetation diversity and stand productivity with a significant level of 5%. Results found that there were 41 tree species in the study site comprising 20 commercial and 21 non-commercial species. The highest richness (R') was recorded in compartment 18X by approximately 4.0, while the most increased heterogeneity (H') and evenness (E') were observed in compartment 18Y by around 2.4 and 0.7, respectively. The accumulation of timber production varied in each site, with a range of 45.46-68.32 m3 ha-1. The highest carbon storage was noted in compartment 19Y (38.74±1.79 t C ha-1), while the lowest was found in compartment 18W (20.76±0.93 t C ha-1). The relative contribution of commercial species to timber production and carbon storage was substantially higher than non-commercial species at all sites. However, there was not a significant correlation between vegetation diversity and stand productivity (P>0.05). Overall, our study concluded that the secondary tropical forest ecosystems in the site had good vegetation diversity, timber production, and carbon storage.

Stand density and species diversity are two indicators that are highly related to forest productivity. However, the effect of those variables on the productivity of community forest is rarely documented. This study evaluates the influence of stand density and species diversity on timber production and carbon stock in the community forest. The study area was located in Madiun District. A field survey was conducted in four different community forest sites, i.e. Morang, Kuwiran, Randualas, and Kare. The sampling technique was by quadrat method using a sample plot size of 25 m x 25 m. The number of sample plots used in this study was 64 units, which were evenly distributed in every site. Comparison of stand attributes among sites was examined by Kruskal-Wallis test and followed by Kruskal-Nemenyi test on the effects of stand density and species diversity on timber production and carbon stock were assessed separately for each parameter using the generalized least square regression test. The process of statistical analysis was applied using a significance level of 5%. Results show a significant difference in stand volume, aboveground biomass, and carbon stock among sites (P<0.05). This study also recorded a meaningful effect of stand density and species diversity on timber production and carbon stock of community forest, wherein stand density provided a higher effect (R2 = 0.68; P<0.05) than species diversity (R2 = 0.26; P<0.05).

Wirabuana PYAP, Setiahadi R, Sadono R, Lukito M, Martono DS, Matatula J. 2020. Allometric equations for estimating biomass of community forest tree species in Madiun, Indonesia. Biodiversitas 21: 4291-4300. The capability of community forests for offsetting carbon emissions highly depends on their biomass production. Unfortunately, the measurement of tree biomass in community forests using a destructive method is expensive and time-consuming. It is also almost impossible to conduct this method for all trees in the observation area. Therefore, the development of allometric equations is essential to support tree biomass estimation in community forests. This study was designed to construct specific models for predicting individual tree biomass in community forests, located in Madiun, Indonesia. We destructively sampled approximately 120 trees from four different species (30 trees for each species), i.e., Falcataria moluccana, Melia azedarach, Swietenia macrophylla, and Tectona grandis. For every tree sample, the measurement of biomass was conducted in each tree’s component, namely roots, stem, branches, and leaves. The allometric equations were developed with regression analysis using predictor variables, like diameter at breast height (D), squared diameter at breast height combined with tree height (D2H), as well as D and H separately. Results found that for four species, the mean biomass in the stem was 50.3%, followed by branches 25.4%, roots 15.9%, and leaves 8.3%. The best equation for estimating biomass in every component and total of four species was different. However, our study showed that the equation lnŶ = -3.037 + 1.430 lnD + 1.684 was reliable to estimate total individual tree biomass of four species in the surveyed area since this model had accuracy of 90.8%. Referring to these findings, we recommended the utilization of an allometric equation as an alternative method for facilitating more efficient biomass measurement in the community forests.