scholarly journals Drivers of aboveground wood production in a lowland tropical forest of West Africa: teasing apart the roles of tree density, tree diversity, soil phosphorus, and historical logging

2016 ◽  
Vol 6 (12) ◽  
pp. 4004-4017 ◽  
Author(s):  
Tommaso Jucker ◽  
Aida Cuni Sanchez ◽  
Jeremy A. Lindsell ◽  
Harriet D. Allen ◽  
Gabriel S. Amable ◽  
...  
2020 ◽  
Vol 712 ◽  
pp. 136405 ◽  
Author(s):  
Seldon Aleixo ◽  
Antonio Carlos Gama-Rodrigues ◽  
Emanuela Forestieri Gama-Rodrigues ◽  
Eduardo Francia Carneiro Campello ◽  
Erika Caitano Silva ◽  
...  

2006 ◽  
Vol 33 (3) ◽  
pp. 256-262 ◽  
Author(s):  
R. SAGAR ◽  
J.S. SINGH

Dry tropical forest communities are among the world's most threatened systems and urgent measures are required to protect and restore them in degraded landscapes. For planning conservation strategies, there is a need to determine the few essential measurable properties, such as number of species and basal area, that best describe the dry forest vegetation and its environment, and to document quantitative relationships among them. This paper examines the relationships between forest basal area and diversity components (number of species and evenness) for a disturbed dry tropical forest of northern India. Data were collected from five sites located in the Vindhyan dry tropical forest of India, selected on the basis of satellite images and field observations to represent the entire range of conditions in terms of canopy cover and disturbance regimes. These sites represented different communities in terms of species composition. The forest was poorer in species richness, and lower in stem density and basal area than wet forests of the tropics. Across sites (communities), the diversity components and tree density were positively related with total tree basal area. Considering basal area as a surrogate of biomass and net production, diversity is found to be positively associated with productivity. A positive relationship between basal area, tree density and species diversity may be an important characteristic of the dry forest, where recurring disturbance does not permit concentration of biomass or stems in only a few strong competitors. However, the relationships of basal area with density, alpha diversity and evenness remain statistically significant only when data from all sites, including the extremely disturbed one, are used in the analysis. In some sites there was a greater coefficient of variation (CV) of basal area than in others, attributed to patchy distribution of stems and resultant blanks. Therefore, to enhance the tree diversity of these forests, the variability in tree basal area must be reduced by regulating local disturbances. Conservation activities, particularly fuelwood plantations near human settlements, deferred grazing and canopy enrichment through multi-species plantations of nursery-raised or wild-collected seedlings of desirable species within the forest patches of low basal area, will be needed to attain restoration goals, but reforestation programmes will have to be made attractive to the forest-dwelling communities.


2016 ◽  
Vol 6 (1) ◽  
pp. 1-12
Author(s):  
Tilak Prasad Gautam ◽  
Tej Narayan Mandal

The disappearance of global tropical forests due to deforestation and forest degradation has reduced the biodiversity and carbon sequestration capacity. In these contexts, present study was carried out to understand the species composition and density in the undisturbed and disturbed stands of moist tropical forest located in Sunsari district of eastern Nepal. Study revealed that the forest disturbance has reduced the number of tree species by 33% and tree density by 50%. In contrary, both number and density of herb and shrub species have increased with forest disturbance.


2018 ◽  
Vol 10 (3) ◽  
pp. 945-953 ◽  
Author(s):  
Akash . ◽  
Navneet . ◽  
B.S. Bhandari

In present study, we present data on tree diversity, stand structures and community composition in six sites of tropical forest in Rajaji tiger reserve, Northern India. The enumeration of 72 plots results a total of 19,050 individuals, 47 species, 42 genera, 25 families in which Holoptelia integrifolea, Dalbergia sissoo, Shorea robusta, Cassia fistula and Trewia nudiflora were the species which showed higher importance value index (IVI) in the study area. The stand density of the six sites ranges from 149.99 - 397.91 hac-1 where as the total basal area of trees ranges from 3.612 - 46.813 m2/hac-1. The Shannon diversity index ranged from 1.35 to 2.51, Simpson index ranged from 0.097 - 0.446, Margalef index ranged 2.584 - 4.9, The Evenness index ranged from  0.551 - 0.852 in the study area. Further the studied area has showed ample evidences from indices in supporting the higher floristic diversity and stand structure after providing the present area as a status of tiger reserve.


2020 ◽  
Vol 10 (15) ◽  
pp. 8429-8438
Author(s):  
Qifeng Mo ◽  
Yiqun Chen ◽  
Shiqin Yu ◽  
Yingxu Fan ◽  
Zhongtong Peng ◽  
...  

2020 ◽  
Vol 12 (11) ◽  
pp. 1829
Author(s):  
Tatiana Nazarova ◽  
Pascal Martin ◽  
Gregory Giuliani

Forests play major roles in climate regulation, ecosystem services, carbon storage, biodiversity, terrain stabilization, and water retention, as well as in the economy of numerous countries. Nevertheless, deforestation and forest degradation are rampant in many parts of the world. In particular, the Amazonian rainforest faces the constant threats posed by logging, mining, and burning for agricultural expansion. In Brazil, the “Sete de Setembro Indigenous Land”, a protected area located in a lowland tropical forest region at the border between the Mato Grosso and Rondônia states, is subject to illegal deforestation and therefore necessitates effective vegetation monitoring tools. Optical satellite imagery, while extensively used for landcover assessment and monitoring, is vulnerable to high cloud cover percentages, as these can preclude analysis and strongly limit the temporal resolution. We propose a cloud computing-based coupled detection strategy using (i) cloud and cloud shadow/vegetation detection systems with Sentinel-2 data analyzed on the Google Earth Engine with deep neural network classification models, with (ii) a classification error correction and vegetation loss and gain analysis tool that dynamically compares and updates the classification in a time series. The initial results demonstrate that such a detection system can constitute a powerful monitoring tool to assist in the prevention, early warning, and assessment of deforestation and forest degradation in cloudy tropical regions. Owing to the integrated cloud detection system, the temporal resolution is significantly improved. The limitations of the model in its present state include classification issues during the forest fire period, and a lack of distinction between natural vegetation loss and anthropogenic deforestation. Two possible solutions to the latter problem are proposed, namely, the mapping of known agricultural and bare areas and its subsequent removal from the analyzed data, or the inclusion of radar data, which would allow a large amount of finetuning of the detection processes.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Emma J. Sayer ◽  
Luis Lopez-Sangil ◽  
John A. Crawford ◽  
Laëtitia M. Bréchet ◽  
Ali J. Birkett ◽  
...  

AbstractSoil organic carbon (SOC) dynamics represent a persisting uncertainty in our understanding of the global carbon cycle. SOC storage is strongly linked to plant inputs via the formation of soil organic matter, but soil geochemistry also plays a critical role. In tropical soils with rapid SOC turnover, the association of organic matter with soil minerals is particularly important for stabilising SOC but projected increases in tropical forest productivity could trigger feedbacks that stimulate the release of stored SOC. Here, we demonstrate limited additional SOC storage after 13–15 years of experimentally doubled aboveground litter inputs in a lowland tropical forest. We combined biological, physical, and chemical methods to characterise SOC along a gradient of bioavailability. After 13 years of monthly litter addition treatments, most of the additional SOC was readily bioavailable and we observed no increase in mineral-associated SOC. Importantly, SOC with weak association to soil minerals declined in response to long-term litter addition, suggesting that increased plant inputs could modify the formation of organo-mineral complexes in tropical soils. Hence, we demonstrate the limited capacity of tropical soils to sequester additional C inputs and provide insights into potential underlying mechanisms.


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