To achieve forest management goal it is important to maintain biodiversity. This paper compares understory plant species diversity between exotic monoculture plantation (Acacia auriculiformis) and adjacent natural sal (Shorea robusta) forest. A total of 35 sample plots were taken by random sampling from six patches of adjacent natural sal forest and exotic monoculture plantation. Shannon-Wiener diversity index, species richness and evenness were calculated and compared. Result revealed that, a total of 2,218 plants of 42 species were recorded in natural sal (Shorea robusta) forest. Dominant families were Apocynaceae and Verbanaceae, having three species in each family. Shannon-Wiener diversity index was 2.1 and mean species richness was 14.4. On the contrary, 2,827 plants were found from 15 species in exotic monoculture (Acacia auriculiformis) plantation study area. Dominant family was Leguminosae family. Three species were found under Leguminosae family. Shannon-Wiener diversity index was 0.86 and mean species richness was 4.47. Therefore, Shannon diversity index and richness were significantly higher in natural sal forest as compared to exotic monoculture plantation. Species evenness of natural sal forest was 0.8 and 0.6 for monoculture plantation which indicates less equitable distribution of understory vegetation in monoculture than adjacent natural sal forest. With regard to herb species, evenness was significantly lower in monoculture plantation (0.03) as compared to natural sal forest (0.52). There was no equitable distribution for the herb species under monoculture plantation. Jaccard’s similarity index showed that 36% shrub species and 30% of herb species were same in exotic monoculture plantation area and adjacent natural sal forest.

Background National forest inventory and forest monitoring systems are more important than ever considering continued global degradation of trees and forests. These systems are especially important in a country like Bangladesh, which is characterised by a large population density, climate change vulnerability and dependence on natural resources. With the aim of supporting the Government’s actions towards sustainable forest management through reliable information, the Bangladesh Forest Inventory (BFI) was designed and implemented through three components: biophysical inventory, socio-economic survey and remote sensing-based land cover mapping. This article documents the approach undertaken by the Forest Department under the Ministry of Environment, Forests and Climate Change to establish the BFI as a multipurpose, efficient, accurate and replicable national forest assessment. The design, operationalization and some key results of the process are presented. Methods The BFI takes advantage of the latest and most well-accepted technological and methodological approaches. Importantly, it was designed through a collaborative process which drew from the experience and knowledge of multiple national and international entities. Overall, 1781 field plots were visited, 6400 households were surveyed, and a national land cover map for the year 2015 was produced. Innovative technological enhancements include a semi-automated segmentation approach for developing the wall-to-wall land cover map, an object-based national land characterisation system, consistent estimates between sample-based and mapped land cover areas, use of mobile apps for tree species identification and data collection, and use of differential global positioning system for referencing plot centres. Results Seven criteria, and multiple associated indicators, were developed for monitoring progress towards sustainable forest management goals, informing management decisions, and national and international reporting needs. A wide range of biophysical and socioeconomic data were collected, and in some cases integrated, for estimating the indicators. Conclusions The BFI is a new information source tool for helping guide Bangladesh towards a sustainable future. Reliable information on the status of tree and forest resources, as well as land use, empowers evidence-based decision making across multiple stakeholders and at different levels for protecting natural resources. The integrated socio-economic data collected provides information about the interactions between people and their tree and forest resources, and the valuation of ecosystem services. The BFI is designed to be a permanent assessment of these resources, and future data collection will enable monitoring of trends against the current baseline. However, additional institutional support as well as continuation of collaboration among national partners is crucial for sustaining the BFI process in future.