Mangrove forest in Lubuk Kertang Village, West Brandan sub-district has been converted around 20 ha annually (1996–2016) into various non-forest land use. Rehabilitation can be a solution to restore the condition of the ecosystem so that it can resume its ecological and economic functions. This paper discusses the evaluation of mangrove rehabilitation carried out by planting 6000 propagules in December 2015 and 5000 seedlings in May 2016 with Rhizophora apiculata species in abandoned ponds. Monitoring was carried out every 6 months from 2016 to 2022. In the restored area, 11 true mangrove species and 3 associated mangrove species were found. The percentage of plants that survived after seven years was 69.42% for planting using propagules and 86.38% for planting with seedlings. The total biomass carbon stocks stored by 7-year-old plants using propagules was 51.18 Mg ha⁻¹, while the carbon stored by planting using seedlings was 56.79 Mg ha⁻¹. Soil carbon stocks at the planted site with propagules were 506.89 ± 250.74 MgC ha⁻¹, and at the planted site with seedlings were 461.85 ± 102.23 MgC ha⁻¹. The total ecosystem carbon stocks (including aboveground carbon) in the planted site using propagules were 558.07 MgC ha⁻¹, while planting using seedlings were 518.64 MgC ha⁻¹. The dataset and findings on the carbon storage evaluation of mangrove rehabilitation will be useful for blue carbon research community and policymakers in the context of the climate change mitigation strategy for Indonesia.

Mangrove forests play an important role in coastal areas from an ecological perspective, being able to store large amounts of carbon through sequestration and inhibiting climate change processes by absorbing CO₂ in the atmosphere. In recent years, there have been changes in the land cover of converted and degraded mangrove forests which have resulted in the release of carbon and an imbalance in soil structure, which in turn cause a flux of CO₂ into the atmosphere. This research was conducted at the Karang Gading and Langkat Timur Laut Wildlife Reserve (KGLTLWR) in North Sumatra, Indonesia. The study focused on six different land covers, namely natural forests, restoration, mixed agriculture, paddy fields, oil palm plantation, and ponds. This study aimed to measure the total carbon stock of mangrove forests that have been converted to other land covers and estimate the level of CO₂ flux in the area. A total of three transects and six plots for each land cover were used in this study; for tree biomass, a non-destructive method was used by recording every DBH > 5 cm, and for soil carbon, drilling was carried out, which was divided into five depths in each plot. CO₂ flux was measured using an Eosense Eosgp CO₂ sensor with the static closed chamber method. The highest carbon stock was found at 308.09 Mg ha⁻¹ in natural forest, while the lowest 3.22 Mg ha⁻¹ was found in mixed agriculture. The highest soil carbon was found at 423.59 MgC ha⁻¹ in natural forest, while the lowest 50.44 MgC ha⁻¹ was found in mixed agriculture dry land. The highest average CO₂ flux value of 1362.24 mgCO₂ m² h⁻¹ was found in mangrove restoration and the lowest in ponds was 123.03 mgCO₂ m² h⁻¹. Overall, the research results inform how much carbon stock is lost when converted to other land covers so that it can be used as a reference for policy makers to provide future management of mangrove forests and develop mitigation measurements to reduce carbon emissions.

High human activity around and in the forest is one of the causes of damage to Sumatran elephant (Elephas maximus sumatranus) habitat in the forest landscape of Besitang. Deforestation and degradation have caused forest fragmentation so that Sumatran elephant habitat becomes narrow. As a result, Sumatran elephants look for a new space outside their natural habitat such as agricultural land and plantations owned by communities around the forest. The conflict between Sumatran elephants and humans cannot be avoided. The objective of this study was to get information about the vulnerability distribution of Sumatran elephant conflict with humans based on the influenced factors in Besitang. The Principal Component Analysis (PCA) method was used to select and weight the factors that are thought to influence the distribution of Sumatran elephant conflict with humans. Overlay analysis of the factors that influence the conflicts distribution between Sumatran elephants and humans was done using Geographic Information System (GIS). The results of the study showed that the vulnerability of human-elephant conflict could be divided into three classes, namely the highly vulnerable areas of conflict which are 43,981.11 ha (26.99%), medium vulnerable areas which are 41,632.74 ha (25.56%) and not vulnerable areas which are 77,291.73 ha (47.45%). The results of the model validation test showed a value of 87.5%.

Sumatra rain forest is a hot spot for flora and fauna biodiversity in the world and also habitat for many endangered species. Of the mammal species, four key species were found here those were Sumatran Tiger (Panthera tigris sumatrae), Sumatran Elephant (Elephas maximus sumatrensis), Orangutan (Pongo abelii) and Sumatran Rhino (Dicerorhinus sumatrensis). Forest degradation has been a global phenomenon and while being an important indicator to further forest loss, decreasing habitat quality of wild animal and species extinction. Besitang Forest is the habitats for three key mammal species in North Sumatra. Forest conversion, forest disturbance, and human activities in this site threaten the existence of this species. The objective of this research was to determine the spatial model of forest canopy cover and spatial distribution of forest degradation in Besitang Forest in period 2008 - 2016. Forest canopy cover value was estimated through Normalized Difference Vegetation Index (NDVI) value from satellite Landsat imagery using the regression model. Forest degradation was measured by comparing the spatial distribution of forest canopy cover in 2008 and forest canopy cover in 2016. The result showed that NDVI approaches could estimate the forest canopy cover with R² value 79.0. Forest degradation in Besitang landscape was classified into high (527.85 ha), medium (9,763.83 ha) and low (28,898.73 ha).

The Besitang forest landscape is a habitat for Sumatran tigers (Panthera tigris sumatrae) which is one of the key species in Gunung Leuser National Park (GLNP). Deforestation and degradation have caused forest fragmentation so that Sumatran tigers habitat becomes narrow. As the first step in modelling the suitability of Sumatran tiger habitat, it is then knowing the distribution of Sumatran tiger prey needs to be done. The objective of this study was to get information about the suitability distribution of Sumatran tigers’ prey based on biophysic and social factors in Besitang. The Principal Component Analysis (PCA) method is used to select and weight the factors that are thought to influence the distribution of Sumatran tiger prey. Overlay analysis of the factors that influence the habitat suitability is done using Geographic Information System (GIS). The results showed that the index value of habitat suitability of Sumatran tigers’ prey has a range of values from 0 to 1. Areas that have values getting closer to number 1 indicate the area is more suitable for the habitat of Sumatran tiger prey.