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 Stand structure indices as tools to support forest management: an application in Trentino forests (Italy)

2013 ◽  
Vol 59 (No. 4) ◽  
pp. 159-168 ◽  
Author(s):  
F. Pastorella ◽  
A. Paletto
Keyword(s):  
Spatial Distribution ◽  
Forest Management ◽  
Species Diversity ◽  
Species Composition ◽  
Tree Species ◽  
Stand Structure ◽  
Composite Index ◽  
Mutual Position ◽  
Tree Species Composition ◽  
North East

Stand structure and species diversity are two useful parameters to provide a synthetic measure of forest biodiversity. The stand structure is spatial distribution, mutual position, diameter and height differentiation of trees in a forest ecosystem and it highly influences habitat and species diversity. The forest stand and species diversity can be measured through indices that provide important information to better address silvicultural practices and forest management strategies in the short and long-term period. These indices can be combined in a composite index in order to evaluate the complex diversity at the stand level. The aim of the paper is to identify and to test a complex index (S-index) allowing to take into account both the tree species composition and the stand structure. S-index was applied in a case study in the north-east of Italy (Trentino province). The results show that the Norway spruce forests in Trentino province are characterized by a medium-low level of complexity (S-index is in a range between 0.14 and 0.46) due to a low tree species composition rather than to the stand structure (diametric differentiation and spatial distribution of trees). &nbsp;

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.

scholarly journals Woody Species Composition, Diversity, and Recovery Six Years after Wind Disturbance and Salvage Logging of a Southern Appalachian Forest

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 129 ◽  
Author(s):  
Callie Oldfield ◽  
Chris Peterson
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Tree Species ◽  
Woody Species ◽  
Hardwood Forest ◽  
Wind Disturbance ◽  
Tree Species Diversity ◽  
Salvage Logging ◽  
Shannon Diversity ◽  
Significant Difference

Salvage logging after wind disturbance of a mixed conifer-hardwood forest results in sapling compositional changes but no changes to species diversity six years post-disturbance. Several conceptual frameworks allow for predictions of the effects of forest disturbances on composition, but fewer yield predictions of species diversity. Following compound disturbance, tree species diversity and composition is predicted to shift to early successional species. Because of the greater cumulative severity, diversity should be lower in areas experiencing windthrow + salvage logging than in similar sites experiencing windthrow alone. We examined the effects of wind disturbance and salvage logging on diversity parameters over six years. We hypothesized that the effects of salvage logging on diversity would be short-lived, but that species composition would be altered six years post-disturbance. Sampling plots were established in a mixed-hardwood forest in north Georgia, USA, after a 2011 EF3 tornado and surveyed in 2012 and 2017. Nineteen 20 × 20 m plots were surveyed (10 unsalvaged, 9 salvaged) for parameters including Shannon diversity, species richness, and composition. Ordinations were used to visualize tree and sapling species composition in salvage logged plots. We found that there was no significant difference in Shannon diversity between salvaged and unsalvaged plots before disturbance, <1 post-disturbance, or 6 years post-disturbance. The disturbances altered the tree and sapling species compositions, with salvaged plots having more mid-successional saplings but few true pioneer species. There appears to be an emerging pattern in the wind disturbance + salvaging literature which our study supports– salvaging does not affect tree species diversity but shifts species composition over time.

scholarly journals Investigating the Relationship between Tree Species Diversity and Landsat-8 Spectral Heterogeneity across Multiple Phenological Stages

2021 ◽  
Vol 13 (13) ◽  
pp. 2467
Author(s):  
Sabelo Madonsela ◽  
Moses A. Cho ◽  
Abel Ramoelo ◽  
Onisimo Mutanga
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Tree Species ◽  
Diversity Indices ◽  
Plant Species Diversity ◽  
Landsat 8 ◽  
Tree Species Diversity ◽  
Phenological Stages ◽  
Species Diversity Indices ◽  
The Relationship

The emergence of the spectral variation hypothesis (SVH) has gained widespread attention in the remote sensing community as a method for deriving biodiversity information from remotely sensed data. SVH states that spectral heterogeneity on remotely sensed imagery reflects environmental heterogeneity, which in turn is associated with high species diversity and, therefore, could be useful for characterizing landscape biodiversity. However, the effect of phenology has received relatively less attention despite being an important variable influencing plant species spectral responses. The study investigated (i) the effect of phenology on the relationship between spectral heterogeneity and plant species diversity and (ii) explored spectral angle mapper (SAM), the coefficient of variation (CV) and their interaction effect in estimating species diversity. Stratified random sampling was adopted to survey all tree species with a diameter at breast height of > 10 cm in 90 × 90 m plots distributed throughout the study site. Tree species diversity was quantified by the Shannon diversity index (H′), Simpson index of diversity (D2) and species richness (S). SAM and CV were employed on Landsat-8 data to compute spectral heterogeneity. The study applied linear regression models to investigate the relationship between spectral heterogeneity metrics and species diversity indices across four phenological stages. The results showed that the end of the growing season was the most ideal phenological stage for estimating species diversity, following the SVH concept. During this period, SAM and species diversity indices (S, H′, D2) had an r2 of 0.14, 0.24, and 0.20, respectively, while CV had an r2 of 0.22, 0.22, and 0.25, respectively. The interaction of SAM and CV improved the relationship between the spectral data and H′ and D2 (from r2 of 0.24 and 0.25 to r2 of 0.32 and 0.28, respectively) at the end of the growing season. The two spectral heterogeneity metrics showed differential sensitivity to components of plant diversity. SAM had a high relationship with H′ followed by D2 and then a lower relationship with S throughout the different phenological stages. Meanwhile, CV had a higher relationship with D2 than other plant diversity indices and its relationship with S and H′ remained similar. Although the coefficient of determination was comparatively low, the relationship between spectral heterogeneity metrics and species diversity indices was statistically significant (p < 0.05) and this supports the assertion that SVH could be implemented to characterize plant species diversity. Importantly, the application of SVH should consider (i) the choice of spectral heterogeneity metric in line with the purpose of the SVH application since these metrics relate to components of species diversity differently and (ii) vegetation phenology, which affects the relationship that spectral heterogeneity has with plant species diversity.

scholarly journals Tree Species Diversity in Secondary Forest of Visayas State University Forest Reservation, Philippines

2007 ◽  
Vol 07 (1) ◽  
pp. 21-35
Author(s):  
Anatolio Polinar ◽  
◽  
Uwe Muuss ◽  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Tree Species ◽  
Secondary Forest ◽  
Middle Layer ◽  
State University ◽  
Tree Species Diversity ◽  
Number Of Species ◽  
The Family

The study was conducted to determine species diversity and similarity within a two-hectare secondary forest of the Visayas State University forest reservation. The diversity value of trees ranged from 3.09 - 4.53. Results of the study indicate that the middle layer of both blocks was observed as the most luxuriant among all layers. A total of 173 species in 113 genera and 51 families; and 92 species, in 69 genera and 37 families were recorded in the middle layer of Block 1 and Block 2, respectively. The genus Ficus of the family Moraceae was identified as the most highly represented in terms of species in both blocks. Moreover, results of the study show that species richness increased within an increasing area but with a decreasing number of species. As to species similarities, it was discovered that 28% of the identified specieds are common to both blocks.

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