Regeneration and Tree Species Diversity of Sitakund Botanical Garden and Eco-Park,Chittagong,Bangladesh

Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park(SBGE), Chittagong,Bangladesh to analyze the natural regeneration and tree species diversity in disturbed and less disturbed zones. Stratified and systematic random sampling was used to select 50 sample plots from each of the two zones. A total number of 109 plant species from 43 families were recorded in the study; of which 93 species were of natural origin while the rest were planted. From the species with natural origin 66 were tree species, 9 were shrub species and 18 were climbers. Species richness, density of regeneration and disturbance index in the height classes(0- 0.5 m)and(dbh > 6 cm) indicated significant differences between the zones. The study analyzed how disturbances affect species diversity in the area. It was found that species richness and basal area are negatively related with disturbances. Moreover,density(N/ha) of trees was more likely to decrease with increasing tree height that reflects the huge demand of local people to harvest large trees as part of their income generating activities. The study findings have implications for future management decisions of the SGBE. To restore these ecosystems, management should focus on both biodiversity conservation and providing benefits to local people without hampering forest ecosystems.

A multi-purpose National Forest Inventory in Bangladesh:design,operationalisation and key results

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 socioeconomic 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.

孟加拉的马缨丹对某些农作物的生长和种子萌发的异种克生现象(英文)

本试验观察马缨丹的提取物对6种常见农作物的生长抑制作用。在24小时光照,平均温度29°C条件下,观察纪录了不同浓度的马缨丹的提取物对农作物生长的影响效果。结果表明:不同浓度的马缨丹的提取物对农作物的根茎的萌发和生长及种子萌发有明显的抑制作用。生物测定表明提取物的浓度的抑制作用表现成比例现象,较高浓度的提取物有较强的抑制作用,较低浓度的提取物对作物生长有一定的刺激作用。这项研究表明提取物对农作物茎和种子的萌发有抑制作用,尤其对根和侧根有更明显的抑制作用。

磷肥对孟加拉几种常见的农林树种苗木生长和根瘤菌固氮作用的影响(英文)

本试验评价了磷肥对孟加拉3种常见的农林树种,耳叶相思(Acacia auriculiformis)、含羞草(Albizia lebbeck)和黄豆树(Albizia procera)的苗木生长和根瘤菌固氮作用的影响。在苗床种植6个月苗龄的耳叶相思、含羞草和黄豆树与对照相比较磷肥对苗木生长和根瘤菌固氮作用的影响。结果表明:磷肥明显提高种苗的生长。对耳叶相思的生长有明显的促进作用,但对含羞草的生长影响不明显,在某种程度上降低了黄豆树的生长。研究也表明,磷肥明显提高植物的根瘤菌的大小与数量。