scholarly journals Method of Estimating Degraded Forest Area: Cases from Dominant Tree Species from Guangdong and Tibet in China

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 930 ◽  
Author(s):  
Biyun Wu ◽  
Xiang Meng ◽  
Qiaolin Ye ◽  
Ram P. Sharma ◽  
Guangshuang Duan ◽  
...  

Forest degradation has been considered as one of the main causes of climate change in recent years. The knowledge of estimating degraded forest areas without the application of remote sensing tools can be useful in finding solutions to resolve degradation problems through appropriate restoration methods. Using the existing knowledge through literature review and field-based primary information, we generated new knowledge by combining the information obtained from multi-criteria decision analyses with an analytic hierarchy process, and this was then used to estimate degraded forest area. Estimation involves determining forest degradation index (FDI) and degradation threshold. Continuous inventory data of permanent sample plots collected from degraded forests, consisting of various forest types divided by dominant tree species in the Guangdong province and Tibet autonomous region of China, were used for the purposes. We identified four different forest degradation levels through the determination and comprehensive evaluation of FDI. The degraded forest area with broad-leaved species as dominant tree species in the Guangdong province was estimated to be 83.3% of a total forest area of 24,037 km2. In the same province, the degraded forest area with eucalyptus as a dominant tree species was 59.5% of a total forest area of 18,665 km2. In the Tibet autonomous region, the degraded forest area with spruce as a dominant tree species was 99.1% of a total forest area of 17,614 km2, and with fir as a dominant tree species, the degraded area was 98.4% of a forest area of 12,103 km2. A sampling accuracy of forest areas with national forest inventory was about 95% in both provinces. Our study concludes that the FDI method used has a certain scientific rationality in estimating degraded forest area. The forest provides a variety of tangible and intangible goods and services for humans. Therefore, forest management should focus on the improvement of its overall productivity, which is only possible with improving forest site quality. One of the important steps to improve the quality of a forest site is to resolve its degradation issues. The presented method in this article will be useful in finding the solutions to forest degradation problems. This method, which does not need any remote sensing tool, is simple and can be easily applied for estimating any degraded forest area and developing effective forest restoration plans.

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250073
Author(s):  
Liu Shu-Qin ◽  
Bian Zhen ◽  
Xia Chao-Zong ◽  
Bilal Ahmad ◽  
Zhang Ming ◽  
...  

According to the forest resources inventory data for different periods and the latest estimation parameters of forest carbon reserves in China, the carbon reserves and carbon density of forest biomass in the Tibet Autonomous Region from 1999 to 2019 were estimated using the IPCC international carbon reserves estimation model. The results showed that, during the past 20 years, the forest area, forest stock, and biomass carbon storage in Tibet have been steadily increasing, with an average annual increase of 1.85×104 hm2, 0.033×107 m3, and 0.22×107 t, respectively. Influenced by geographical conditions and the natural environment, the forest area and biomass carbon storage gradually increased from the northwest to the southeast, particularly in Linzhi and Changdu, where there are many primitive forests, which serve as important carbon sinks in Tibet. In terms of the composition of tree species, coniferous forests are dominant in Tibet, particularly those containing Abies fabri, Picea asperata, and Pinus densata, which comprise approximately 45% of the total forest area in Tibet. The ecological location of Tibet has resulted in the area being dominated by shelter forest, comprising 68.76% of the total area, 64.72% of the total forest stock, and 66.34% of the total biomass carbon reserves. The biomass carbon storage was observed to first increase and then decrease with increasing forest age, which is primarily caused by tree growth characteristics. In over-mature forests, trees’ photosynthesis decreases along with their accumulation of organic matter, and the trees can die. In addition, this study also observed that the proportion of mature and over-mature forest in Tibet is excessively large, which is not conducive to the sustainable development of forestry in the region. This problem should be addressed in future management and utilization activities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paula M. A. Fiedler ◽  
Alice De Lapparent ◽  
Jeremie Razafitsalama ◽  
Justin Sanamo ◽  
Kim J. E. Steffens ◽  
...  

AbstractForest restoration is a prime goal within the 2021–2030 UN “Decade of Ecosystem Resoration”. As part of these activities, natural regeneration has to be promoted for biological as well as for economic reasons. For this, the processes of seed dispersal, seed predation and germination have to be understood in the original as well as in degraded vegetation formations. We used seed removal experiments to assess post-dispersal processes that influence recruitment along a gradient of forest degradation in Madagascar analyzing seeds of three animal dispersed tree species. The percentage of seeds consumed or dispersed, declined from forest (28.6%) to degraded forest (17.2%) to savanna (10.8%). Only three out of 1080 seeds were cached and remained intact during the 14-day experiment. All three seeds were cached in the forest habitat and none in the degraded forest and savanna. The low percentage of seeds removed may be due to the lack of endemic rodents caching seeds, as only introduced rats were recorded in the area. The species-poor fauna of potential secondary seed dispersers of the region and especially in the degraded areas might represent an obstacle for diverse regeneration in degraded regions of Madagascar.


2017 ◽  
Vol 7 (3) ◽  
pp. 120-127
Author(s):  
O. B. Bondar ◽  
L. I. Tkach ◽  
O. O. Chuikova ◽  
A. S. Zolotarova

Typological analysis of watershed forests of the Seversky Donets River was carried out on the basis of forest management data with electronic databases of "Ukrderzhlisproekt" Production Association. More than 27 types of forest were analyzed with total size of 228.2 thousand hectares. The classification of forest growth conditions, forest types and tree species on the left and right banks of the Seversky Donets River was done for the Luhansk region. We determined that the forest fund of the Luhansk region consists from the oak forests – 46.4 %, sudubrava – 21.1 %, conifer forest – 17.5 %. The proportion of coniferous forests makes up to 15.0 % of total forest area. We calculated that the area of common oak and common pine is 86.9 and 70.9·103 ha respectively. The following types of forests are prevailing: dry birchbark-marple sudubrava (30.8 %), fresh oak-pine sudubrava (13.1%), dry Tatarian maple sudubrava (12.9%), and fresh pine forest (10.6%). In the forest area of the Luhansk region we registered 70 tree species, of which 19 species – in oak-pine forest; 37 – in conifer forest; 55 – in sudubrava; 59 – in oak forest. By categories of protection the recreation forests (51.7 %) and protective forests (42.0 %) are the dominant. The forests of nature protection, forests of scientific, historical and cultural significance have only 6.4 % from the total forest area. The structure of forests by age groups was: middle-aged forests – 41.3 %, young growths – 17.8 %, ripening forests – 15.5 %, mature forests – 16.7 %, and old growth forests – 13.3 % from total forest area of Luhansk region.


2010 ◽  
Vol 161 (8) ◽  
pp. 286-290
Author(s):  
Adrian Borgula

Where nature protection is concerned, the expert assessment of an environment poses questions about its natural and cultural heritage and its potential, about how representative it may be, about biodiversity in all its facets and about its development or potential threats to its existence. Although the forest was the dominant habitat in the original natural European landscape, for a long time nature protection has devoted too little attention to it. There are diverse threats and deficiencies. However, in the Swiss forests positive developments are discernible. Thus nature protection is one of the basic functions of the forest, nature reserves are being created, the area of the forest is increasing, as are reserves of deadwood, and greater importance is being given to regeneration suited to the site. Nevertheless much remains to be done to really achieve the goal of biodiversity and sus-tainability. For this purpose segregative and integrative measures are required. Since diversity needs surface area, in the first place it must be possible to set aside as forest reserves a quarter of the total forest area, spread over the whole country and preferably as natural forest reserves, in order to start the process of a long-term restoration to the natural state. Here the conservation of natural self-regulating processes supersedes classical nature protection. With a series of further integrative measures, biodiversity must also be promoted over the whole remaining forest area and in the areas of transition to other habitats. An abundance of varied structures is the key to diversity of species. A more courageous attitude to wilderness and “untidiness” when dealing with the forest is to be recommended. Nature experiences in wilderness areas give the population the possibility of discovering diversity and natural processes and encourage respect for the innumerable other species and habitats.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ying Wang ◽  
Bing-Cheng Ma ◽  
Li-Ying Wang ◽  
Gongsang Quzhen ◽  
Hua-Sheng Pang

Abstract Background Echinococcosis is highly endemic in western and northern China. Tibet Autonomous Region (TAR) is the most serious prevalent area. Linzhi is located in southeastern part of TAR. Dogs are the primary infection source for the transmission of echinococcosis to humans. A control and prevention campaign based on dog management has been implemented in the past three years. This study aims to evaluate the effects of dog management on the infection rate of dogs. Methods Data of dog population, registration and de-worming of seven counties/district in Linzhi between 2017 and 2019 were obtained from the annual prevention and control report. Domestic dog fecal samples were collected from each endemic town of seven counties/district in Linzhi in 2019 to determine the infection of domestic dogs using coproantigen enzyme-linked immunosorbent assay (ELISA). Data analysis was processed using SPSS statistics to compare dog infection rate between 2016 and 2019 by chi-square test, and maps were mapped using ArcGIS. Results In Linzhi, domestic dog population has decreased from 17 407 in 2017 to 12 663 in 2019, while the registration rate has increased from 75.9% in 2017 to 98.6% in 2019. Similarly, stray dog population has decreased from 14 336 in 2017 to 11 837 in 2019, while sheltered rate has increased from 84.6% in 2017 to 96.6% in 2019. Dog de-worming frequency has increased from 4 times per annum in 2017 to 12 times in 2019, indicating that approximately every dog was dewormed monthly. A total of 2715 dog fecal samples were collected for coproantigen ELISA assay. The dog infection rate was 2.8% (77/2715) in 2019, which was significantly lower than 7.3% (45/618) in 2016 (P < 0.05). Conclusions Increased dog registration, decreased dog population, and increased dog de-worming frequency contributed to significantly decrease the dog infection rate in Linzhi. Control and prevention campaign based on dog management could significantly decrease dog infection with Echinococcus spp. in echinococcosis endemic areas.


2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Praveen Kumar ◽  
Akhouri P. Krishna ◽  
Thorkild M. Rasmussen ◽  
Mahendra K. Pal

Optical remote sensing data are freely available on a global scale. However, the satellite image processing and analysis for quick, accurate, and precise forest above ground biomass (AGB) evaluation are still challenging and difficult. This paper is aimed to develop a novel method for precise, accurate, and quick evaluation of the forest AGB from optical remote sensing data. Typically, the ground forest AGB was calculated using an empirical model from ground data for biophysical parameters such as tree density, height, and diameter at breast height (DBH) collected from the field at different elevation strata. The ground fraction of vegetation cover (FVC) in each ground sample location was calculated. Then, the fraction of vegetation cover (FVC) from optical remote sensing imagery was calculated. In the first stage of method implementation, the relation model between the ground FVC and ground forest AGB was developed. In the second stage, the relational model was established between image FVC and ground FVC. Finally, both models were fused to derive the relational model between image FVC and forest AGB. The validation of the developed method was demonstrated utilizing Sentinel-2 imagery as test data and the Tundi reserved forest area located in the Dhanbad district of Jharkhand state in eastern India was used as the test site. The result from the developed model was ground validated and also compared with the result from a previously developed crown projected area (CPA)-based forest AGB estimation approach. The results from the developed approach demonstrated superior capabilities in precision compared to the CPA-based method. The average forest AGB estimation of the test site obtained by this approach revealed 463 tons per hectare, which matches the previous estimate from this test site.


2021 ◽  
Vol 13 (6) ◽  
pp. 1131
Author(s):  
Tao Yu ◽  
Pengju Liu ◽  
Qiang Zhang ◽  
Yi Ren ◽  
Jingning Yao

Detecting forest degradation from satellite observation data is of great significance in revealing the process of decreasing forest quality and giving a better understanding of regional or global carbon emissions and their feedbacks with climate changes. In this paper, a quick and applicable approach was developed for monitoring forest degradation in the Three-North Forest Shelterbelt in China from multi-scale remote sensing data. Firstly, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Ratio Vegetation Index (RVI), Leaf Area Index (LAI), Fraction of Photosynthetically Active Radiation (FPAR) and Net Primary Production (NPP) from remote sensing data were selected as the indicators to describe forest degradation. Then multi-scale forest degradation maps were obtained by adopting a new classification method using time series MODerate Resolution Imaging Spectroradiometer (MODIS) and Landsat Enhanced Thematic Mapper Plus (ETM+) images, and were validated with ground survey data. At last, the criteria and indicators for monitoring forest degradation from remote sensing data were discussed, and the uncertainly of the method was analyzed. Results of this paper indicated that multi-scale remote sensing data have great potential in detecting regional forest degradation.


Sign in / Sign up

Export Citation Format

Share Document