scholarly journals Stability in subtropical forests: The role of tree species diversity, stand structure, environmental and socio‐economic conditions

Author(s):  
Shuai Ouyang ◽  
Wenhua Xiang ◽  
Mengmeng Gou ◽  
Liang Chen ◽  
Pifeng Lei ◽  
...  
2016 ◽  
Vol 8 (2) ◽  
pp. 95-101
Author(s):  
Thi Thanh Huong Nguyen ◽  
Thi Nhu Quynh Chau

This paper describes the influence of elevation on woody tree species diversity in Nam Kar Natural Reserve of Daklak, of which remote sensing and GIS techniques were used as the tools in biodiversity inventory and assessment. The whole Reserve area was divided into four elevation classes based on DEM (Digital Elevation Model) using GIS technique. Landsat 8 satellite image was employed to stratify the forest into the four strata. A total of 4 transect lines of 100 m in length and 20 m in width (abbreviated as H1, H2, H3, and H4) established in east-west direction representing for 4 elevation classes was used for surveying biodiversity and stand structure. The different diversity indices were compared among the different elevation classes. The relationships between reflectance value of sat- ellite image, forest strata with biodiversity indices were also analysed. The result shows that the diversity of woody tree species is different among elevation classes. Based on sample plots a total of 135 tree species belonging to 42 genera was found in this area. Although a low inverse correlations were found between number of species composition, basal area, and tree density with DNs, most correlation was statistically insignificant 95%. However, a medium relation between forest strata and number of species composition were found with correlation coefficient r = 0.53 (P<0.00) in the area. Nghiên cứu này đánh giá đa dạng thực vật thân gỗ tại khu bảo tồn thiên nhiên Nam Kar theo các cấp độ cao khác nhau. Nghiên cứu đã sử dụng ảnh vệ tinh và kỹ thuật GIS để hỗ trong trong việc điều tra và đánh giá đa dạng sinh học. Toàn bộ khu bảo tồn được chia thành 4 cấp độ cao dựa vào mô hình số độ cao (DEM) được thực hiện bằng kỹ thuật GIS. Ảnh Landsat 8 đã được sử dụng để phân chia rừng thành 4 khối trạng thái. Có 4 ô tiêu chuẩn dạng dải có kích thước 100m chiều dài và 20m chiều rộng được đặt ở từng đai cao (viết tắt là H1, H2, H3, và H4) theo hướng cố định Đông – Tây để điều tra đa dạng sinh học và cấu trúc lâm phần của thực vật thân gỗ ở từng đai cao. Các chỉ số đa dạng sinh học đã được so sánh trong từng cấp độ cao. Mối quan hệ giữa giá trị ảnh, hiện trạng rừng với các chỉ số đa dạng cũng được phân tích. Kết quả nghiên cứu cho thấy có sự khác biệt về đa dạng loài thực vật thân gỗ theo từng đai cao. Dựa vào ô mẫu nghiên cứu cũng đã ước tính có 135 loài thuộc 42 chi có trong vùng nghiên cứu. Một số đặc điểm lâm phần như thành phần loài, tiết diệt ngang bình quân và mật độ cây có mối tương quan nghịch với giá trị ảnh vệ tinh tuy nhiên mối quan hệ này không có ý nghĩa thống kê ở độ tin cậy 95%. Tuy vậy nghiên cứu cho thấy có mối tương quan tương quan khá chặt giữa số loài và các khối hiện trạng rừng với hệ số tương quan là 0.53 ở mức P<0.00.


2019 ◽  
Vol 3 (1) ◽  
pp. 10-19 ◽  
Author(s):  
MD. RAYHANUR RAHMAN ◽  
Md. MIZANUR RAHMAN ◽  
Md. ARIF CHOWDHURY ◽  
JARIN AKHTER

Abstract. Rahman MdR, Rahman MdM, Chowdhury MdA, Akhter J. 2019. Tree species diversity and structural composition: The case of Durgapur Hill Forest, Netrokona, Bangladesh. Asian J For 3: 10-19. Tree species diversity and stand structure of Durgapur hill forest were assessed through stratified random sampling method using sample plots of 20 m x 20 m in size during the period of October 2017 to May 2018. A total of 1436 stems of ≥5 cm DBH of 56 tree species belonging to 50 genera and 29 families were enumerated from sample area. Density (855 stem ha-1) and Basal area (29.27 m2 ha-1) of tree species were enumerated. Besides, Shannon-Wiener’s, Margalef’s, Simpson’s and Pielou’s diversity index were recorded for all the tree species. The study showed that the most dominant 10 species have 58% of the total IVI (174.29 out of 300). Where, Acacia auriculiformis showed the maximum Importance Value Index (51.02) followed by Shorea robusta (24.23). Number of individual tree species were highest (49) in the height range of 7- <12 m whereas maximum (52) species were recorded in the DBH (cm) range of 5- <10 cm. However, Acacia auriculiformis, Shorea robusta, and Tectona grandis were found as the most dominant species based on hierarchical cluster analysis. Therefore, current study will be helpful to the future policymakers in formulating forest resource management plan of Durgapur hill forest.


2015 ◽  
Vol 4 ◽  
pp. 185-196 ◽  
Author(s):  
Tran Van Do ◽  
Tamotsu Sato ◽  
Satoshi Saito ◽  
Osamu Kozan ◽  
Hiromi Yamagawa ◽  
...  

2019 ◽  
Vol 35 (2) ◽  
pp. 46-56 ◽  
Author(s):  
Paul Musili Mutuku ◽  
David Kenfack

AbstractStand structure and tree species diversity patterns were examined plot-wide and among four topographically defined habitats (plateau, cliff, low plain and depressions) in a 120-ha permanent plot in an Acacia-dominated savanna in Mpala Ranch, central Kenya. The four habitats were defined by clustering the 3000 quadrats of 20 × 20 m in the plot based on their altitude, slope and convexity. Structural and floristic differences among the four habitats were examined and species-habitat associations were tested for the 30 most abundant species using torus translation randomization tests. The plot included 113 337 trees in 62 species with diameter at knee height ≥ 2 cm (18.4 species ha−1), 41 genera and 23 families. Fabaceae with the genus Acacia were the dominant family, followed by Euphorbiaceae and Ebenaceae. Tree density and basal area were twice as high on low plain and depressions than on the plateau. Species richness was highest in the cliff and was seven times higher than in the adjacent plateau. Half of the species assessed showed significant positive associations with one habitat and 21 showed significant negative associations with at least one habitat. The variation in stand structure and tree species diversity within the Mpala plot shows that topography is among the important drivers of local species distribution and hence the maintenance of tree diversity in savannas.


2013 ◽  
Vol 70 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Lichao Wu ◽  
Jie Liu ◽  
Atsushi Takashima ◽  
Keiichi Ishigaki ◽  
Shin Watanabe

Sign in / Sign up

Export Citation Format

Share Document