Effect of local topographic heterogeneity on tree species assembly in an Acacia-dominated African savanna

2019 ◽  
Vol 35 (2) ◽  
pp. 46-56 ◽  
Author(s):  
Paul Musili Mutuku ◽  
David Kenfack
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Stand Structure ◽  
Basal Area ◽  
Abundant Species ◽  
Habitat Associations ◽  
Tree Species Diversity ◽  
Knee Height ◽  
Local Species ◽  
Topographic Heterogeneity

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.

scholarly journals TREE SPECIES DIVERSITY IN A PRISTINE MONTANE FOREST PREVIOUSLY UNTOUCHED BY HUMAN ACTIVITIES IN FOJA MOUNTAINS, PAPUA, INDONESIA

REINWARDTIA ◽  
2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Asep Sadili ◽  
Kuswata Kartawinata ◽  
Herwasono Soedjito ◽  
Edy Nasriadi Sambas
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Human Activities ◽  
Diversity Index ◽  
Basal Area ◽  
Montane Forest ◽  
Tree Species Diversity ◽  
Importance Value ◽  
Montane Forests ◽  
Species Area

ADILI, A., KARTAWINATA, K., SOEDJITO, H. & SAMBAS, E. N. 2018. Tree species diversity in a pristine montane forest previously untouched by human activities in Foja Mountains, Papua, Indonesia. Reinwardtia 17(2): 133‒154. ‒‒ A study on structure and composition of the pristine montane forest previously untouched by human activities was conducted at the Foja Mountains in November 2008. We established a one-hectare plot divided into 100 subplots of 10 m × 10 m each. We enumerated all trees with DBH ≥ 10 cm which diameters were measured, heights were estimated and habitats were noted. We recorded 59 species, 42 genera and 27 families, comprising 693 trees with the total basal area (BA) of 41.35 m2/ha. The forest had lower species richness compared to those of lowland forests in Kalimantan, and Sumatra and montane forests in West Java. The Shannon-Wiener’s diversity index was 3.22. Nothofagus rubra (Importance Value, IV=47.89%) and Parinari corymbosa (IV=40.3%) were the dominant species, constituting the basis for designating the forest as the Nothofagus rubra - Parinari corymbosa association. To date, the dominance of N. rubra is unique to the Foja Mountains, as elsewhere in Papua the montane forests were dominated by N. pullei or other species. The species-area curve indicated a minimal area of 5000 m2. On the family level Fagaceae (IV=53.23%), Chrysobalanaceae (IV=40.53%) and Myristicaceae (IV=26.43%) were dominant. Verti-cally the forest consisted of four strata (A–D). In each stratum Nothofagus rubra, Platea latifolia, Parinari corymbosa and Myristica hollrungii were dominant. The diameter class distribution of Nothofagus rubra, Parinari corymbosa and Platea latifolia led us to assume that these species were regenerating well.

scholarly journals The Influence of Tree Structural and Species Diversity on Temperate Forest Productivity and Stability in Korea

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1113 ◽  
Author(s):  
Juhan Park ◽  
Hyun Seok Kim ◽  
Hyun Kook Jo ◽  
II Bin Jung
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Temperate Forest ◽  
Temperate Forests ◽  
Basal Area ◽  
Stand Density ◽  
Structural Diversity ◽  
Forest Productivity ◽  
Tree Species Diversity ◽  
Positive Effect

Research Highlights: Using a long-term dataset on temperate forests in South Korea, we established the interrelationships between tree species and structural diversity and forest productivity and stability, and identified a strong, positive effect of structural diversity, rather than tree species diversity, on productivity and stability. Background and Objectives: Globally, species diversity is positively related with forest productivity. However, temperate forests often show a negative or neutral relationship. In those forests, structural diversity, instead of tree species diversity, could control the forest function. Materials and Methods: This study tested the effects of tree species and structural diversity on temperate forest productivity. The basal area increment and relative changes in stand density were used as proxies for forest productivity and stability, respectively. Results: Here we show that structural diversity, but not species diversity, had a significant, positive effect on productivity, whereas species diversity had a negative effect, despite a positive effect on diversity. Structural diversity also promoted fewer changes in stand density between two periods, whereas species diversity showed no such relation. Structurally diverse forests might use resources efficiently through increased canopy complexity due to canopy plasticity. Conclusions: These results indicate reported species diversity effects could be related to structural diversity. They also highlight the importance of managing structurally diverse forests to improve productivity and stability in stand density, which may promote sustainability of forests.

Forest regeneration in northeastern Poland following a catastrophic blowdown

2015 ◽  
Vol 45 (9) ◽  
pp. 1172-1182 ◽  
Author(s):  
Dorota Dobrowolska
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Natural Regeneration ◽  
Large Scale ◽  
Stand Structure ◽  
Basal Area ◽  
Tree Height ◽  
Ground Cover ◽  
Species Structure ◽  
Tree Vitality

The aims of the investigation were to (i) quantify the changes in natural regeneration and stand structure, (ii) determine the role of deadwood in the process of regeneration following the disturbance, and (iii) determine the effect of disturbance severity on tree recruitment. The study was conducted in the Szast Protected Forest, which was established after a blowdown in 2002. The results showed that the trees were mainly wind-snapped. The basal area of the slightly disturbed stands increased over time. Herb cover increased, whereas moss cover decreased in 2011. The disturbance severity influenced the density of tree species regeneration, moss and herb ground cover, species diversity, average tree height, tree vitality, and damage caused by herbivores. The density of natural regeneration increased and new species became established after the disturbance. Scots pine (Pinus sylvestris L.) was the dominant tree species during the regeneration process except in the severely disturbed stand from which wood had been removed; in this case, birch was the dominant species. Wind disturbance increased species diversity and created a new forest with a particular species structure and trees that varied in age and height. The results of this study will be useful for foresters and policymakers to change the existing approaches to large-scale disturbances in the Polish forests.

scholarly journals Influence of elevations on woody tree species diversity in Nam Kar Natural Reserve of Daklak province, Vietnam

2016 ◽  
Vol 8 (2) ◽  
pp. 95-101
Author(s):  
Thi Thanh Huong Nguyen ◽  
Thi Nhu Quynh Chau
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Tree Species ◽  
Stand Structure ◽  
Satellite Image ◽  
Landsat 8 ◽  
Tree Species Diversity ◽  
Number Of Species ◽  
Natural Reserve ◽  
Forest Strata

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.

scholarly journals Estimation of Ecosystem Carbon Stock and Tree Species Diversity at National Botanical Garden, Dhaka, Bangladesh

2019 ◽  
pp. 1-11
Author(s):  
Md. Delwar Hossain ◽  
Md. Ehsanul Haq ◽  
Manna Salwa ◽  
Md. Nazmul Islam Shekh ◽  
Aisha Siddika ◽  
...  
Keyword(s):  
Species Diversity ◽  
Organic Carbon ◽  
Tree Species ◽  
Carbon Stock ◽  
Basal Area ◽  
Botanical Garden ◽  
Mean Value ◽  
Biomass Carbon ◽  
Tree Species Diversity ◽  
Ecosystem Carbon

The study was conducted from January to April 2018 to estimate ecosystem carbon stock and tree species diversity at National Botanical Garden, Bangladesh. Transects line method square plots with a size of 20 m × 20 m were used. So altogether there were total eighty-three sample plots in National Botanical Garden. Above ground carbon (AGC) and below ground carbon (BGC) biomass stock was 192.67 and 31.34, respectively and soil organic carbon mean value of 27.52 Mg ha-1, 21.45 Mg ha-1 and 16.23 Mg ha-1, respectively for 0-10 cm depth, 10-20 cm and 20-30 cm depth. The average number of tree species per hectare was 128 with a mean value of each plot 3.00 to 9.00 species. The average number of trees in National Botanical Garden (233 tree ha-1), basal area (21.45 m2 ha-1) and mean DBH (39.86 cm). Tree diversity range from 0.25 to 1.86 and the mean value of (0.93 ± 0.14) in National Botanical Garden. A relationship such as biomass carbon with the basal area, mean DBH, stem density and tree diversity were estimated. Among these, the relationship between basal area and biomass carbon showed positive significant correlation. Therefore, the results of the study confirmed that the selected botanical garden can serve as a valuable ecological tool in terms of carbon sequestration, diverse tree species and storage of soil organic carbon.

scholarly journals Tree species diversity and structural composition: The case of Durgapur Hill Forest, Netrokona, Bangladesh

2019 ◽  
Vol 3 (1) ◽  
pp. 10-19 ◽  
Author(s):  
MD. RAYHANUR RAHMAN ◽  
Md. MIZANUR RAHMAN ◽  
Md. ARIF CHOWDHURY ◽  
JARIN AKHTER
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Stand Structure ◽  
Diversity Index ◽  
Acacia Auriculiformis ◽  
Tree Species Diversity ◽  
Individual Tree ◽  
Height Range ◽  
Structural Composition ◽  
Shorea Robusta

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.

Sign in / Sign up

Export Citation Format

Share Document