This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information...This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted.展开更多
Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bang...Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bangladesh. The effects of P-fertilizer on seedling growth and nodulation were comparcd to that of seedlings grown in unfertilized soil or in control at different harvesting intervals. The study revealed that, seedling growth was enhanced significantly with the application of P-fertilizer. The growth was found more pronounced in cases of A. saman and P. pinnata, whereas it was not noticeable and showed depressed growth in case of A. chinensis. The study also suggests that nodulation in terms of nodule number and size was also increased significantly with P-fertilization except in case ofP. pinnata, where higher harvesting intervals lowered the nodulation performance of that species展开更多
An experiment was conducted to assess the effect of Phosphorous （P） fertilizer （i.e. TSP or triple super phosphate @ 80 kg/hm^2） on seedling growth and nodulation capabilities of three potentially important agrofo...An experiment was conducted to assess the effect of Phosphorous （P） fertilizer （i.e. TSP or triple super phosphate @ 80 kg/hm^2） on seedling growth and nodulation capabilities of three potentially important agroforestry tree species （Acacia auriculiformis, Albizia lebbeck and Albizia procera） of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control （i.e. unfertilized soil）. The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer.展开更多
The effects of different inorganic fertilizers （Urea and Triple Super Phosphate （TSP）） on seedling growth and nodulation capabilities of four agroforestry tree species （Albizia chinensis, A. saman, Acacia nilotic...The effects of different inorganic fertilizers （Urea and Triple Super Phosphate （TSP）） on seedling growth and nodulation capabilities of four agroforestry tree species （Albizia chinensis, A. saman, Acacia nilotica and Sesbania sesban） were compared. The nodulation of these seedlings were treated with different fertilizer treatments （at the rate of urea 40 kg·hm^-2, urea 80 kg·hm^-2 TSP 40 kg·hm^-2, TSP 80 kg·hm^-2, （urea＋TSP） 40 kghm 2 and （urea＋TSP） 80 kg·hm^-2） after one month of seed germination. The results revealed that the seedling growth was enhanced significantly with moderate fertilizer treatment. In some cases, the higher levels of fertilizers reduced the seedling growth. The study also revealed that the nodulation in nodule number and size was significantly inhibited by the application of N fertilizer （Urea）, while it was increased significantly with the application of P fertilizer （TSP）. This study improved our understanding and provided insights that would be useful to the farmers in their efforts to amend the soil with inorganic fertilizers in order to enhance plant growth and biological nitrogen fixation.展开更多
A study was conducted to investigate the cultural and financial management techniques of betel leaf based agroforestry system practiced in or near homegardens of Khasia community in Jaintapur Upazila in the district o...A study was conducted to investigate the cultural and financial management techniques of betel leaf based agroforestry system practiced in or near homegardens of Khasia community in Jaintapur Upazila in the district of Sylhet, Bangladesh.The Khasia is an educated community where 100% of Khasia people were literate, a stunning fact for this ethnic community in Bangladesh.The average family size in the study area was 7.68, with a ration of male and females of 141:100.The homegardens of the Khasia are rich in species composi-tion, which 15 timber species, 22 horticultural species, six medicinal species, 13 annual crops including leafy vegetables, seven species of spices and five species of bamboo were identified along with betel leaf.The Khasia is an economically prosperous community with the minimum family incomes of Tk 4 000 per month(Tk.70=1 US Dollar).Betel leaf based agroforestry is very common being a prevalent source of income.About 95.45% of the households are involved in betel leaf husbandry.The mean annual income from one hectare of betel leaf plantation was estimated to be Tk.80979.This practice was proven to be a profitable business where the benefit cost ratio was calculated to be 4.47.Moreover, the species composition in the betel leaf plantation area(the forest area once utilized by Khasia for shifting cultivation) was found to be very promising to play the significant role in conservation of biological diversity making the practice a sus-tainable agroforestry system.展开更多
A study was conducted in Madhupur sal forest of Tangail, Bangladesh to identify the suitable agroforestry practices of the area. Considering the ecological aspects of different agroforestry practices 10 sample plots ...A study was conducted in Madhupur sal forest of Tangail, Bangladesh to identify the suitable agroforestry practices of the area. Considering the ecological aspects of different agroforestry practices 10 sample plots （10 m× 10 m） from each land uses were taken, including natural forest to get a comparative scenario. The study showed that among the different agroforestry practices, Margalef and Shannon- Weiner index values are the maximum for pineapple agroforestry and lower for banana agroforestry, and Evenness index value is the maximum for lemon agroforestry. Determination of tree biomass in different land uses revealed that it is highest （3 078.6 kg/100 m^2） in natural forest followed by pineapple agroforestry, lemon agroforestry and banana agroforestry. Soil pH, moisture content, organic matter, organic carbon, phosphorus and total nitrogen showed statistically significant variation while bulk density, particle density, sulphur and potassium did not show any statistically significant variation among the land uses. Soil fertility status showed that pineapple agroforestry is more fertile than rest of other land uses. The Net Present Value （NPV） indicated that banana agroforestry is financially more profitable than other two systems, while the Benefit- Cost ratio （BCR） is higher in pineapple agroforestry （4.21 in participatory agroforestry and 3.35 in privately managed land）. Even though banana agroforestry gives higher NPV, capital required for this practice is much higher. The findings suggest that pineapple agroforestry has a tendency towards becoming ecologically and economically more sound than other two practices as it has better ecological attributes and required comparatively low investment.展开更多
A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking an...A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking and policies related to human/environmental worlds at local, regional, and global scales. Maps are an important part of these innovative and ongoing research approaches. In this context, we consider urban forests a topic meriting more attention of scholars studying the geographic and environmental intersections of the natural sciences with the social sciences and humanities. We construct two innovative knowledge bases, one a conceptual framework based on major themes and concepts related to mapping urban forests using key words of the first 100 results of a Google Scholar query and a second using the number of Google Scholar hyperlinks about mapping urban forests in 244 capital cities. We discovered that the constructed world maps reveal vast global unevenness in our knowledge about urban forests in hyperlink numbers and ratios, results that merit further attention by disciplinary, international and interdisciplinary scholarly communities.展开更多
Mammal distribution is shaped by different ecological and anthropogenic factors,and the pattern varies depending on their sensitivity thresholds,food and habitat preferences,ecological roles,and physical traits.The pr...Mammal distribution is shaped by different ecological and anthropogenic factors,and the pattern varies depending on their sensitivity thresholds,food and habitat preferences,ecological roles,and physical traits.The present study investigated the influence of ecological and anthropogenic factors on the distribution of mammal species communities across different trophic levels and body sizes in Myanmar's Htamanthi Wildlife Sanctuary(HWS).The values of mammal characteristics,ecological,and anthropogenic factors were analyzed in ArcMap software.Most of the large and small sized mammals,whose distribution decreases with elevation,were observed near the main streams.Across mammal tropic levels,the omnivores and herbivores were mostly observed farther from gold mining sites.In terms of forage plant effect on mammal community,floral forage plants and the presence of climber negatively affected mammal species across different trophic levels.Moreover,presence of resin trees also has a substantial impact on the distribution of medium-large animals and omnivorous mammals as trophic niche factors.Overall,our findings highlight the crucial role that ecological and anthropogenic factors play in shaping mammal distribution in the HWS.This underscores the importance of simultaneously conserving both habitat and mammal diversity in HWS,especially in the face of a changing climate and environment.展开更多
Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. ...Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops： Falen （Vigna unguiculata）, Chickpea （Cicer arietinum）, Arhor （Cajanus cajan） and two widely used plantation trees： Sada koroi （Albizia procera） and Ipil ipil （Leucaena leucocephala） were selected as bioassay species. Experiment was set on tray at room temperature 27℃. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E, camaldulesis induced inhibitory effects, It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.展开更多
Santalum album （Indian Sandalwood） is found in the mountainous regions of the intermediate zone of Sri Lanka. Few studies have been conducted on sandalwood ecology in this region, and ours is the first recorded stud...Santalum album （Indian Sandalwood） is found in the mountainous regions of the intermediate zone of Sri Lanka. Few studies have been conducted on sandalwood ecology in this region, and ours is the first recorded study of essential oil content and chemical composition of heartwood. We harvested two trees with State permission and took cross-sections for analysis. We demonstrated a difference in the heartwood formation and oil yield of the trees. The composition of the oil was found to be consistent between trees and along the trunk of the tree. Main aromatic compounds were santalols and other compounds are recorded in lesser quantities. Results of this study comply with the other published work on sandalwood elsewhere. This initial study on S. album in Sri Lanka provided promising results for the future of sandalwood agroforestry.展开更多
Objective Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the perfo...Objective Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the performance of DNA barcodes for identification of the most threatening poisonous plants in China. Methods Seventy-four accessions of 27 toxic plant species in 22 genera and 17 families were sampled and three DNA barcodes （motK, rbcL, and ITS） were amplified, sequenced and tested. Three methods, Blast, pairwise global alignment （PWG） distance, and Tree-Building were tested for discrimination power. Results The primer universality of all the three markers was high. Except in the case of ITS for Hemerocollis minor, the three barcodes were successfully generated from all the selected species. Among the three methods applied, Blast showed the lowest discrimination rate, whereas PWG Distance and Tree-Building methods were equally effective. The ITS barcode showed highest discrimination rates using the PWG Distance and Tree-Building methods. When the barcodes were combined, discrimination rates were increased for the Blast method.展开更多
Albizia saman （Jacq.） F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nurs...Albizia saman （Jacq.） F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nursery.The experiment was established in the nursery of the Institute of Forestry and Environmental Sciences.University of Chittagong, Chittagong, Bangladesh. Results revealed that Nail clipping in one side of the seed （at the distal end of the seed） （T4） provides the highest （50%） seed germination. The second highest germination （42%） was obtained for the seeds treated with immersion in cold water for 24 h （T1）. Germination was completely inhibited when the seeds immersed in boiled water for 30 s followed in cold water soaking for 24 h. Other germination parameter and initial morphological growth and biomass production of the seedlings was also higher for the treatments T4and Ti in comparison to the control （Ta）treatment. Pre-sowing treatments of T4 e.g. Nail clipping in one side of the seed （at the distal end of the seed） and T1 （Seeds immersed in cold water for 24 h） may be recommended for maximum germination and initial vigorous seedlings growth of Albizia sarnan in the nursery.展开更多
The effect of forests clear felling and associated burning on the population of soil nitrogen transforming bacteria and actinomycetes are reported at three pair sites of Chittagong University campus, Bangla- desh in m...The effect of forests clear felling and associated burning on the population of soil nitrogen transforming bacteria and actinomycetes are reported at three pair sites of Chittagong University campus, Bangla- desh in monsoon tropical climate. Clear felled area or burnt site and 15-21 year mixed plantation of native and exotic species, situated side by side on low hill having Typic Dystrochrepts soil was represented at each pair site. At all the three pair sites, clear felled area or burnt site showed very significantly （p~_0.001） lower population of actinomycetes, Rhizobium, Nitrosomonas, Nitrobacter and ammonifying as well as deni- trifying bacteria compared to their adjacent mixed plantation. From en- vironmental consideration, this finding has implication in managing natural ecosystem.展开更多
Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）trees.The present study assessed composition,structure ...Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）trees.The present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 families.The forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance indices.Dipterocarpus turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value index.Syzygium firmum and Tectona grandis followed in terms of dominance.The structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DBH and 16–20 m height ranges）,whereas D.turbinatus was the only species that dominated most of the growth classes.Poor stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and encroachments.This study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of Bangladesh.It will also contribute to identifying threatened plants to undertake D.turbinatus based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.展开更多
A study was carried out to determine the influence of different types of sludges （municipal, industrial and residential） on field germination, growth and nodulation of L. leucocephala seedlings in the nursery. Befor...A study was carried out to determine the influence of different types of sludges （municipal, industrial and residential） on field germination, growth and nodulation of L. leucocephala seedlings in the nursery. Before sowing of seeds, different combinations of sludges were incorporated with the nutrient deficient natural forest soils. Field germination, nodulation status and physical growth parameters of seedlings （shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total dry biomass increment） were recorded after three and six months of seed sowing. Field germination, nodulation status and growth parameters were varied significantly in the soil amended with sludges in comparison to control. The highest number of nodule was recorded from soil amended with residential sludge （ 1：1 ） and highest fresh and dry nodule weight was also found from the same combination in both three and six month old seedlings. In case of growth parameters, the highest growth was recorded from soil and residential sludge （ 1：1 ） combination compared to control. From the study, it can be recommended that soil amended with residential sludge （ 1：1 ） provide better field germination, growth and nodule formation of L. leucocephala in degraded soil.展开更多
Status of organic carbon (C), total nitrogen (N), available potassium (K), calcium (Ca) and phosphorus (P) in three different depths (0-5 cm, 5-15 cm and 15?30 cm) on two hill slopes of 35% and 55% in orange orchard c...Status of organic carbon (C), total nitrogen (N), available potassium (K), calcium (Ca) and phosphorus (P) in three different depths (0-5 cm, 5-15 cm and 15?30 cm) on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts (CHTs) were evaluated and compared with those in degraded bush forests, through digging three profiles in each land use. The content of all the five nutrients was found to be higher in the soil of orange orchard than in the soil of forest. But the variation was not consistent for both the slopes. The content varied depth wise also, having the highest value in surface soil in case of both the land uses on both the slopes. A mean available K content was significantly higher in orange orchard than in forest on 55% slope, while it was lower on 35% slope. Surface soil contained the nutrients of K and Ca with the amount of 0.2905-mg·g^(-1) soil and 3.025-mg·g^(-1)soil respectively in the orchard, while 0.1934-mg·g^(-1) soil and 1.6083-mg·g^(-1) soil were respectively in the forest. Organic carbon and total nitrogen were found more or less similar in surface soil on both the land uses showing a slight difference. Available P was found only in orange orchard, and in forest it was too little in amount to detect by the spectrophotometer. The degraded forests were poor in nutrient content due to high rate of soil erosion, which would be possible to be improved by bringing it under tree cover as proved by the adaptation of orange orchard there.展开更多
Establishment of Protected Areas （PAs）, in the face of rapid deforestation, forest degradation and climate change has been one of the key efforts in conservation of biodiversity worldwide in recent times. While Bang...Establishment of Protected Areas （PAs）, in the face of rapid deforestation, forest degradation and climate change has been one of the key efforts in conservation of biodiversity worldwide in recent times. While Bangladesh has gained a degree of prominence in the world for its successful social forestry programs, the concept of collaborative pro- tected area management is rather new in the country, initiated in 2004 by the Bangladesh Forest Department in five PAs with financial assistance from USAID. Based on empirical evidence from three of the pilot PAs, we examined the achievements and associated challenges and prospects for co-management. Our fieldwork revealed a number of challenges faced by co-management institutions： （1） institutions were dominated by the elite group, overshadowing the voice of the community people; （2） mutual trust and collective performance are key to good governance but had not taken root in the PAs; （3） encroachment onto forest land and subsequent conversion to agriculture remained a serious problem that discouraged forest-dependent people from participating actively in co-management initiatives; （4） legal provisions （including acts, rules and policies） were not clearly and adequately disseminated and understood at the community level; （5） there remained a degree of ambiguity regarding the roles and responsibilities of forest department （FD） and co-management committees （CMC） in field operations, and this was not enhancing transparency and accountability of the overall initiative; （6） the long-term sustainability of co-management institutions was another major concern, as the local intuitional structure was still in a nascent stage, and provisioning of resources （either internally or externally） remained somewhat uncertain. We offer recommendations for improve- ment.展开更多
An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi （Albizia procera）, Ipil ipil （L. leucocephala） and three agricultural crops Falen （Vigna ung...An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi （Albizia procera）, Ipil ipil （L. leucocephala） and three agricultural crops Falen （Vigna unguiculata）, Chickpea （Citer arietinum） and Arhor （Cajanus cajan） in the nursery of the Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh, in a Randomized Block Design. Results suggested that leaf litters ofL. leucocephala induced inhibitory effects on germination and growth of bioassay. It was also found that the effect depended on concentration of extract and litterfall, type of receptor species. Higher concentration of the materials had the higher effect and vice versa. Growth response of receptor crops varied with the variation of leaf litter application. The study revealed that application of low-dose leaf litter specially litter of 10 g·m^-2 had stimulating effect on shoot growth of C. arietinum, Vunguiculata and A. procera. While in all other cases significant inhibitory effect was observed and it was significantly increased with the increase of leaf litter application. However, the trend of inhibition was uneven with treatments. Root growth was found to be more affected than shoot growth.展开更多
Soil samples were collected and analyzed from 25 sites of three hilly regions(Rangamati,Banderban and Khagrachari)for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts,Bangla...Soil samples were collected and analyzed from 25 sites of three hilly regions(Rangamati,Banderban and Khagrachari)for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts,Bangladesh.There were natural forests,bushy land,slashed sites,slashed and burnt sites,and the sites prepared for shifting cultivation,one year after shifting cultivation and two years after shifting cultivation.The soils were generally yellowish brown to reddish brown,sandy to sandy clay loam,strongly acid,and well to excessively drained on steep slopes with considerable variation among the sites and land use categories.Bulk density was the highest in sites of one year after shifting cultivation(1.52 g·cm^-3)and the lowest in forested sites(1.38 g·cm^-3).Water holding capacities were,however,statistically similar in all sites.Organic carbon varied from 0.54%(slashed and burnt sites)to 1.55%(forested sites)and total N ranged from 0.05%(shifting cultivation for one year)to 0.13%(forested sites).Available phosphorus(Bray&Kurtz-2 P)was the maximum in forested sites(12.32 mg·kg^-l),and it did not differ significantly in other sites.Contents of available Ca,Mg and K were also higher in the bushy lands and forested sites than cleared and shifting cultivated sites.展开更多
The physical properties of soil on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts （CHTs） were evaluated and compared with those of bushy hill forests. Soil sam...The physical properties of soil on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts （CHTs） were evaluated and compared with those of bushy hill forests. Soil samples were collected from three different depths （0-5 cm, 5-15 cm and 15-30 cm）, digging three profiles in each land use for determining moisture content, organic matter content and particle density. Maximum water holding capacity, field capacity, dry and moist bulk density and porosity were determined only for the surface soils. Moisture content at all the soil depths was significantly higher （p≤ 0.05） in orange orchard than in forest on both the slopes. Orange orchard contained lower mean soil organic matter than forest on 55% slope, while it contained higher values on 35% slope compared to forest. The highest value of the above two properties was found at surface soil in both the land uses on both the slopes, decreasing with the increase of soil depth. On both the slopes maximum water holding capacity and porosity of surface soil and particle density at all soil depths were lower in orange orchard compared to those in forest. Field capacity values of surface soil did not show consistency in trend for the differences between the two land uses on both the slopes. Bulk density value of moist and dry surface soil was higher in orange orchard than in forest on both the hill slopes.展开更多
文摘This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted.
文摘Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bangladesh. The effects of P-fertilizer on seedling growth and nodulation were comparcd to that of seedlings grown in unfertilized soil or in control at different harvesting intervals. The study revealed that, seedling growth was enhanced significantly with the application of P-fertilizer. The growth was found more pronounced in cases of A. saman and P. pinnata, whereas it was not noticeable and showed depressed growth in case of A. chinensis. The study also suggests that nodulation in terms of nodule number and size was also increased significantly with P-fertilization except in case ofP. pinnata, where higher harvesting intervals lowered the nodulation performance of that species
文摘An experiment was conducted to assess the effect of Phosphorous （P） fertilizer （i.e. TSP or triple super phosphate @ 80 kg/hm^2） on seedling growth and nodulation capabilities of three potentially important agroforestry tree species （Acacia auriculiformis, Albizia lebbeck and Albizia procera） of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control （i.e. unfertilized soil）. The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer.
文摘The effects of different inorganic fertilizers （Urea and Triple Super Phosphate （TSP）） on seedling growth and nodulation capabilities of four agroforestry tree species （Albizia chinensis, A. saman, Acacia nilotica and Sesbania sesban） were compared. The nodulation of these seedlings were treated with different fertilizer treatments （at the rate of urea 40 kg·hm^-2, urea 80 kg·hm^-2 TSP 40 kg·hm^-2, TSP 80 kg·hm^-2, （urea＋TSP） 40 kghm 2 and （urea＋TSP） 80 kg·hm^-2） after one month of seed germination. The results revealed that the seedling growth was enhanced significantly with moderate fertilizer treatment. In some cases, the higher levels of fertilizers reduced the seedling growth. The study also revealed that the nodulation in nodule number and size was significantly inhibited by the application of N fertilizer （Urea）, while it was increased significantly with the application of P fertilizer （TSP）. This study improved our understanding and provided insights that would be useful to the farmers in their efforts to amend the soil with inorganic fertilizers in order to enhance plant growth and biological nitrogen fixation.
文摘A study was conducted to investigate the cultural and financial management techniques of betel leaf based agroforestry system practiced in or near homegardens of Khasia community in Jaintapur Upazila in the district of Sylhet, Bangladesh.The Khasia is an educated community where 100% of Khasia people were literate, a stunning fact for this ethnic community in Bangladesh.The average family size in the study area was 7.68, with a ration of male and females of 141:100.The homegardens of the Khasia are rich in species composi-tion, which 15 timber species, 22 horticultural species, six medicinal species, 13 annual crops including leafy vegetables, seven species of spices and five species of bamboo were identified along with betel leaf.The Khasia is an economically prosperous community with the minimum family incomes of Tk 4 000 per month(Tk.70=1 US Dollar).Betel leaf based agroforestry is very common being a prevalent source of income.About 95.45% of the households are involved in betel leaf husbandry.The mean annual income from one hectare of betel leaf plantation was estimated to be Tk.80979.This practice was proven to be a profitable business where the benefit cost ratio was calculated to be 4.47.Moreover, the species composition in the betel leaf plantation area(the forest area once utilized by Khasia for shifting cultivation) was found to be very promising to play the significant role in conservation of biological diversity making the practice a sus-tainable agroforestry system.
文摘A study was conducted in Madhupur sal forest of Tangail, Bangladesh to identify the suitable agroforestry practices of the area. Considering the ecological aspects of different agroforestry practices 10 sample plots （10 m× 10 m） from each land uses were taken, including natural forest to get a comparative scenario. The study showed that among the different agroforestry practices, Margalef and Shannon- Weiner index values are the maximum for pineapple agroforestry and lower for banana agroforestry, and Evenness index value is the maximum for lemon agroforestry. Determination of tree biomass in different land uses revealed that it is highest （3 078.6 kg/100 m^2） in natural forest followed by pineapple agroforestry, lemon agroforestry and banana agroforestry. Soil pH, moisture content, organic matter, organic carbon, phosphorus and total nitrogen showed statistically significant variation while bulk density, particle density, sulphur and potassium did not show any statistically significant variation among the land uses. Soil fertility status showed that pineapple agroforestry is more fertile than rest of other land uses. The Net Present Value （NPV） indicated that banana agroforestry is financially more profitable than other two systems, while the Benefit- Cost ratio （BCR） is higher in pineapple agroforestry （4.21 in participatory agroforestry and 3.35 in privately managed land）. Even though banana agroforestry gives higher NPV, capital required for this practice is much higher. The findings suggest that pineapple agroforestry has a tendency towards becoming ecologically and economically more sound than other two practices as it has better ecological attributes and required comparatively low investment.
文摘A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking and policies related to human/environmental worlds at local, regional, and global scales. Maps are an important part of these innovative and ongoing research approaches. In this context, we consider urban forests a topic meriting more attention of scholars studying the geographic and environmental intersections of the natural sciences with the social sciences and humanities. We construct two innovative knowledge bases, one a conceptual framework based on major themes and concepts related to mapping urban forests using key words of the first 100 results of a Google Scholar query and a second using the number of Google Scholar hyperlinks about mapping urban forests in 244 capital cities. We discovered that the constructed world maps reveal vast global unevenness in our knowledge about urban forests in hyperlink numbers and ratios, results that merit further attention by disciplinary, international and interdisciplinary scholarly communities.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1A2C201017812)support of‘R&D Program for Forest Science Technology(Project No.2022461B10-2424-0201)’provided by Korea Forest Service(Korea Forestry Promotion Institute)。
文摘Mammal distribution is shaped by different ecological and anthropogenic factors,and the pattern varies depending on their sensitivity thresholds,food and habitat preferences,ecological roles,and physical traits.The present study investigated the influence of ecological and anthropogenic factors on the distribution of mammal species communities across different trophic levels and body sizes in Myanmar's Htamanthi Wildlife Sanctuary(HWS).The values of mammal characteristics,ecological,and anthropogenic factors were analyzed in ArcMap software.Most of the large and small sized mammals,whose distribution decreases with elevation,were observed near the main streams.Across mammal tropic levels,the omnivores and herbivores were mostly observed farther from gold mining sites.In terms of forage plant effect on mammal community,floral forage plants and the presence of climber negatively affected mammal species across different trophic levels.Moreover,presence of resin trees also has a substantial impact on the distribution of medium-large animals and omnivorous mammals as trophic niche factors.Overall,our findings highlight the crucial role that ecological and anthropogenic factors play in shaping mammal distribution in the HWS.This underscores the importance of simultaneously conserving both habitat and mammal diversity in HWS,especially in the face of a changing climate and environment.
基金Intercooperation,Agroforestry Improvement Project and Village and Farm Forestry Project (IC-VFFP, AFIP) Rajshahi (Funded by Swiss Agency for Development Cooperation,SDC)
文摘Allelopathic effects of different doses of Eucalyptus camaldulensis leaf litters were investigated through an experiment in the green house of Institute of Forestry and Environmental Sciences, Chittagong, Bangladesh. Three popular agricultural crops： Falen （Vigna unguiculata）, Chickpea （Cicer arietinum）, Arhor （Cajanus cajan） and two widely used plantation trees： Sada koroi （Albizia procera） and Ipil ipil （Leucaena leucocephala） were selected as bioassay species. Experiment was set on tray at room temperature 27℃. The effects of different doses of leaf litter extracts were compared to the control. Results suggest that leaf litters of E, camaldulesis induced inhibitory effects, It was also found that the effect depend on concentration of extract and litterfall, type of receiver species. Higher concentration of the materials had the higher effect and vice versa. Though all the bioassay species were suppressed some of them showed better performance. Vigna unguiculata, Cicer arietinum are recommended in agroforestry based on this present Experiment output. In mixed plantation, Leucaena leucochephala is a better choice while compared to Albizia procera.
基金the financial support provided by Sadaharitha Plantations Ltdservices provided by Wescorp Sandalwood Ltd
文摘Santalum album （Indian Sandalwood） is found in the mountainous regions of the intermediate zone of Sri Lanka. Few studies have been conducted on sandalwood ecology in this region, and ours is the first recorded study of essential oil content and chemical composition of heartwood. We harvested two trees with State permission and took cross-sections for analysis. We demonstrated a difference in the heartwood formation and oil yield of the trees. The composition of the oil was found to be consistent between trees and along the trunk of the tree. Main aromatic compounds were santalols and other compounds are recorded in lesser quantities. Results of this study comply with the other published work on sandalwood elsewhere. This initial study on S. album in Sri Lanka provided promising results for the future of sandalwood agroforestry.
基金supported by the Fundamental Research Funds for the Central Universities(grant no.TD2012-04)the Scientific Research Foundation of the State Human Resource Ministry and the Education Ministry for Returned Chinese Scholars(to L.Xie)+2 种基金the State Key Laboratory Program from the State Key Laboratory of Systematic and Evolutionary Botany(grant no.LSEB2011-07)the Main Direction Program of Knowledge Innovation of the Chinese Academy of Sciences(grant no.KSCX2-EW-Z-1)the National Natural Science Foundation of China(grant nos.31170201,81072317,31110103911)
文摘Objective Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the performance of DNA barcodes for identification of the most threatening poisonous plants in China. Methods Seventy-four accessions of 27 toxic plant species in 22 genera and 17 families were sampled and three DNA barcodes （motK, rbcL, and ITS） were amplified, sequenced and tested. Three methods, Blast, pairwise global alignment （PWG） distance, and Tree-Building were tested for discrimination power. Results The primer universality of all the three markers was high. Except in the case of ITS for Hemerocollis minor, the three barcodes were successfully generated from all the selected species. Among the three methods applied, Blast showed the lowest discrimination rate, whereas PWG Distance and Tree-Building methods were equally effective. The ITS barcode showed highest discrimination rates using the PWG Distance and Tree-Building methods. When the barcodes were combined, discrimination rates were increased for the Blast method.
文摘Albizia saman （Jacq.） F. Muell. commonly known as rain tree seeds were treated with five pre-sowing treatments to study the effect of pre-sowing treatments on germination and initial seedling development in the nursery.The experiment was established in the nursery of the Institute of Forestry and Environmental Sciences.University of Chittagong, Chittagong, Bangladesh. Results revealed that Nail clipping in one side of the seed （at the distal end of the seed） （T4） provides the highest （50%） seed germination. The second highest germination （42%） was obtained for the seeds treated with immersion in cold water for 24 h （T1）. Germination was completely inhibited when the seeds immersed in boiled water for 30 s followed in cold water soaking for 24 h. Other germination parameter and initial morphological growth and biomass production of the seedlings was also higher for the treatments T4and Ti in comparison to the control （Ta）treatment. Pre-sowing treatments of T4 e.g. Nail clipping in one side of the seed （at the distal end of the seed） and T1 （Seeds immersed in cold water for 24 h） may be recommended for maximum germination and initial vigorous seedlings growth of Albizia sarnan in the nursery.
文摘The effect of forests clear felling and associated burning on the population of soil nitrogen transforming bacteria and actinomycetes are reported at three pair sites of Chittagong University campus, Bangla- desh in monsoon tropical climate. Clear felled area or burnt site and 15-21 year mixed plantation of native and exotic species, situated side by side on low hill having Typic Dystrochrepts soil was represented at each pair site. At all the three pair sites, clear felled area or burnt site showed very significantly （p~_0.001） lower population of actinomycetes, Rhizobium, Nitrosomonas, Nitrobacter and ammonifying as well as deni- trifying bacteria compared to their adjacent mixed plantation. From en- vironmental consideration, this finding has implication in managing natural ecosystem.
文摘Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan（Dipterocarpus spp.）trees.The present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 families.The forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance indices.Dipterocarpus turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value index.Syzygium firmum and Tectona grandis followed in terms of dominance.The structural composition indicated higher number of individuals in the medium growth classes（41 to 〈 511 cm DBH and 16–20 m height ranges）,whereas D.turbinatus was the only species that dominated most of the growth classes.Poor stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and encroachments.This study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of Bangladesh.It will also contribute to identifying threatened plants to undertake D.turbinatus based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.
文摘A study was carried out to determine the influence of different types of sludges （municipal, industrial and residential） on field germination, growth and nodulation of L. leucocephala seedlings in the nursery. Before sowing of seeds, different combinations of sludges were incorporated with the nutrient deficient natural forest soils. Field germination, nodulation status and physical growth parameters of seedlings （shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total dry biomass increment） were recorded after three and six months of seed sowing. Field germination, nodulation status and growth parameters were varied significantly in the soil amended with sludges in comparison to control. The highest number of nodule was recorded from soil amended with residential sludge （ 1：1 ） and highest fresh and dry nodule weight was also found from the same combination in both three and six month old seedlings. In case of growth parameters, the highest growth was recorded from soil and residential sludge （ 1：1 ） combination compared to control. From the study, it can be recommended that soil amended with residential sludge （ 1：1 ） provide better field germination, growth and nodule formation of L. leucocephala in degraded soil.
文摘Status of organic carbon (C), total nitrogen (N), available potassium (K), calcium (Ca) and phosphorus (P) in three different depths (0-5 cm, 5-15 cm and 15?30 cm) on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts (CHTs) were evaluated and compared with those in degraded bush forests, through digging three profiles in each land use. The content of all the five nutrients was found to be higher in the soil of orange orchard than in the soil of forest. But the variation was not consistent for both the slopes. The content varied depth wise also, having the highest value in surface soil in case of both the land uses on both the slopes. A mean available K content was significantly higher in orange orchard than in forest on 55% slope, while it was lower on 35% slope. Surface soil contained the nutrients of K and Ca with the amount of 0.2905-mg·g^(-1) soil and 3.025-mg·g^(-1)soil respectively in the orchard, while 0.1934-mg·g^(-1) soil and 1.6083-mg·g^(-1) soil were respectively in the forest. Organic carbon and total nitrogen were found more or less similar in surface soil on both the land uses showing a slight difference. Available P was found only in orange orchard, and in forest it was too little in amount to detect by the spectrophotometer. The degraded forests were poor in nutrient content due to high rate of soil erosion, which would be possible to be improved by bringing it under tree cover as proved by the adaptation of orange orchard there.
文摘Establishment of Protected Areas （PAs）, in the face of rapid deforestation, forest degradation and climate change has been one of the key efforts in conservation of biodiversity worldwide in recent times. While Bangladesh has gained a degree of prominence in the world for its successful social forestry programs, the concept of collaborative pro- tected area management is rather new in the country, initiated in 2004 by the Bangladesh Forest Department in five PAs with financial assistance from USAID. Based on empirical evidence from three of the pilot PAs, we examined the achievements and associated challenges and prospects for co-management. Our fieldwork revealed a number of challenges faced by co-management institutions： （1） institutions were dominated by the elite group, overshadowing the voice of the community people; （2） mutual trust and collective performance are key to good governance but had not taken root in the PAs; （3） encroachment onto forest land and subsequent conversion to agriculture remained a serious problem that discouraged forest-dependent people from participating actively in co-management initiatives; （4） legal provisions （including acts, rules and policies） were not clearly and adequately disseminated and understood at the community level; （5） there remained a degree of ambiguity regarding the roles and responsibilities of forest department （FD） and co-management committees （CMC） in field operations, and this was not enhancing transparency and accountability of the overall initiative; （6） the long-term sustainability of co-management institutions was another major concern, as the local intuitional structure was still in a nascent stage, and provisioning of resources （either internally or externally） remained somewhat uncertain. We offer recommendations for improve- ment.
文摘An experiment was conducted to assess the effect of leaf litter of Leucaena leucocephala on two forest crops Sada koroi （Albizia procera）, Ipil ipil （L. leucocephala） and three agricultural crops Falen （Vigna unguiculata）, Chickpea （Citer arietinum） and Arhor （Cajanus cajan） in the nursery of the Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh, in a Randomized Block Design. Results suggested that leaf litters ofL. leucocephala induced inhibitory effects on germination and growth of bioassay. It was also found that the effect depended on concentration of extract and litterfall, type of receptor species. Higher concentration of the materials had the higher effect and vice versa. Growth response of receptor crops varied with the variation of leaf litter application. The study revealed that application of low-dose leaf litter specially litter of 10 g·m^-2 had stimulating effect on shoot growth of C. arietinum, Vunguiculata and A. procera. While in all other cases significant inhibitory effect was observed and it was significantly increased with the increase of leaf litter application. However, the trend of inhibition was uneven with treatments. Root growth was found to be more affected than shoot growth.
文摘Soil samples were collected and analyzed from 25 sites of three hilly regions(Rangamati,Banderban and Khagrachari)for an understanding of the impact of denudation and land use on soils in Chittagong Hill Tracts,Bangladesh.There were natural forests,bushy land,slashed sites,slashed and burnt sites,and the sites prepared for shifting cultivation,one year after shifting cultivation and two years after shifting cultivation.The soils were generally yellowish brown to reddish brown,sandy to sandy clay loam,strongly acid,and well to excessively drained on steep slopes with considerable variation among the sites and land use categories.Bulk density was the highest in sites of one year after shifting cultivation(1.52 g·cm^-3)and the lowest in forested sites(1.38 g·cm^-3).Water holding capacities were,however,statistically similar in all sites.Organic carbon varied from 0.54%(slashed and burnt sites)to 1.55%(forested sites)and total N ranged from 0.05%(shifting cultivation for one year)to 0.13%(forested sites).Available phosphorus(Bray&Kurtz-2 P)was the maximum in forested sites(12.32 mg·kg^-l),and it did not differ significantly in other sites.Contents of available Ca,Mg and K were also higher in the bushy lands and forested sites than cleared and shifting cultivated sites.
文摘The physical properties of soil on two hill slopes of 35% and 55% in orange orchard cultivated by the Mro tribe of Chittagong Hill Tracts （CHTs） were evaluated and compared with those of bushy hill forests. Soil samples were collected from three different depths （0-5 cm, 5-15 cm and 15-30 cm）, digging three profiles in each land use for determining moisture content, organic matter content and particle density. Maximum water holding capacity, field capacity, dry and moist bulk density and porosity were determined only for the surface soils. Moisture content at all the soil depths was significantly higher （p≤ 0.05） in orange orchard than in forest on both the slopes. Orange orchard contained lower mean soil organic matter than forest on 55% slope, while it contained higher values on 35% slope compared to forest. The highest value of the above two properties was found at surface soil in both the land uses on both the slopes, decreasing with the increase of soil depth. On both the slopes maximum water holding capacity and porosity of surface soil and particle density at all soil depths were lower in orange orchard compared to those in forest. Field capacity values of surface soil did not show consistency in trend for the differences between the two land uses on both the slopes. Bulk density value of moist and dry surface soil was higher in orange orchard than in forest on both the hill slopes.
