Remote Sensing of Forest Regeneration in Highland Tropical Forests

2005 ◽  
Vol 42 (1) ◽  
pp. 66-79 ◽  
Author(s):  
Alexis Aguilar
Keyword(s):  
Remote Sensing ◽  
Tropical Forests ◽  
Forest Regeneration

scholarly journals Estimated Density, Population Size and Distribution of the Endangered Western Hoolock Gibbon (Hoolock hoolock) in Forest Remnants in Bangladesh

Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 490
Author(s):  
Habibon Naher ◽  
Hassan Al-Razi ◽  
Tanvir Ahmed ◽  
Sabit Hasan ◽  
Areej Jaradat ◽  
...  
Keyword(s):  
Population Size ◽  
Tropical Forests ◽  
Forest Regeneration ◽  
Distance Sampling ◽  
Suitable Habitat ◽  
Careful Evaluation ◽  
Maxent Model ◽  
Maxent Modeling ◽  
Forest Remnants ◽  
Density Population

Tropical forests are threatened worldwide due to deforestation. In South and Southeast Asia, gibbons (Hylobatidae) are important to seed dispersal and forest regeneration. Most gibbons are threatened due to deforestation. We studied the western hoolock gibbon (Hoolock hoolock) in Bangladesh to determine population size and extent of suitable habitat. We used distance sampling to estimate density across 22 sites in northeastern and southeastern Bangladesh. We used Maxent modeling to determine areas of highly suitable habitat throughout Bangladesh. Density was estimated to be 0.39 ± 0.09groups/km2, and the total estimated population was 468.96 ± 45.56 individuals in 135.31 ± 2.23 groups. The Maxent model accurately predicted gibbon distribution. Vegetation cover, isothermality, annual precipitation, elevation and mean temperature of the warmest quarter influenced distribution. Two areas in the northeast and two areas in the southeast have high potential for gibbon conservation in Bangladesh. We also found significantly more gibbons in areas that had some level of official protection. Thus, we suggest careful evaluation, comprehensive surveys and restoration of habitats identified as suitable for gibbons. We recommend bringing specific sites in the northeastern and southeastern regions under protection to secure habitat for remaining gibbon populations.

Regional ecosystem structure and function: ecological insights from remote sensing of tropical forests

2007 ◽  
Vol 22 (8) ◽  
pp. 414-423 ◽  
Author(s):  
Jeffrey Q. Chambers ◽  
Gregory P. Asner ◽  
Douglas C. Morton ◽  
Liana O. Anderson ◽  
Sassan S. Saatchi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tropical Forests ◽  
Structure And Function ◽  
Ecosystem Structure ◽  
And Function ◽  
Ecosystem Structure And Function

Taxonomy and remote sensing of leaf mass per area (LMA) in humid tropical forests

2011 ◽  
Vol 21 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Gregory P. Asner ◽  
Roberta E. Martin ◽  
Raul Tupayachi ◽  
Ruth Emerson ◽  
Paola Martinez ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tropical Forests ◽  
Leaf Mass Per Area ◽  
Leaf Mass

scholarly journals Seed dispersal by Ceratogymna hornbills in the Dja Reserve, Cameroon

1998 ◽  
Vol 14 (3) ◽  
pp. 351-371 ◽  
Author(s):  
KENNETH D. WHITNEY ◽  
MARK K. FOGIEL ◽  
AARON M. LAMPERTI ◽  
KIMBERLY M. HOLBROOK ◽  
DONALD J. STAUFFER ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Tropical Forests ◽  
Tree Species ◽  
Forest Regeneration ◽  
Germination Rate ◽  
Gut Passage ◽  
Forest Elephants ◽  
Seed Dispersers ◽  
Passage Times

Seed dispersal is a process critical to the maintenance of tropical forests, yet little is known about the interactions of most dispersers with their communities. In the Dja Reserve, Cameroon, seed dispersal by the hornbills Certaogymna atrata, C. cylindricus and C. fistulator (Aves: Bucerotidae) was evaluated with respect to the taxonomic breadth of plants dispersed, location of seed deposition and effects on seed germination. Collectively, the three hornbill species consumed fruits from 59 tree and liana species, and likely provided dispersal for 56 of them. Hornbill-dispersed tree species composed 22% of the known tree flora of the site. Hornbill visit lengths, visit frequencies, and seed passage times indicated that few seeds were deposited beneath parent trees; in five hornbill/tree species pairings studied, 69–100% of the seeds ingested were deposited away from the parent trees. Germination trials showed that hornbill gut passage is gentle on seeds. Of 24 tree species tested, 23 germinated after passage by hornbills; of 17 planted with controls taken directly from trees, only four species showed evidence of inhibition of germination rate, while seven experienced unchanged germinated rates and six experienced enhanced germination rates. Results suggested that Certaogymna hornbill rank among the most important seed dispersers found in Afrotropical forests, and they deserve increased conservation attention. Ceratogymna hornbills are likely to become increasingly important in forest regeneration as populations of larger mammalian seed dispersers (such as forest elephants and primates) diminish.

scholarly journals Persistent collapse of biomass in Amazonian forest edges following deforestation leads to unaccounted carbon losses

2020 ◽  
Vol 6 (40) ◽  
pp. eaaz8360 ◽  
Author(s):  
Celso H. L. Silva Junior ◽  
Luiz E. O. C. Aragão ◽  
Liana O. Anderson ◽  
Marisa G. Fonseca ◽  
Yosio E. Shimabukuro ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Tropical Forests ◽  
Forest Fragmentation ◽  
Edge Effect ◽  
Carbon Emissions ◽  
Forest Edges ◽  
Amazonian Forest ◽  
Primary Driver ◽  
The Tropics ◽  
Carbon Losses

Deforestation is the primary driver of carbon losses in tropical forests, but it does not operate alone. Forest fragmentation, a resulting feature of the deforestation process, promotes indirect carbon losses induced by edge effect. This process is not implicitly considered by policies for reducing carbon emissions in the tropics. Here, we used a remote sensing approach to estimate carbon losses driven by edge effect in Amazonia over the 2001 to 2015 period. We found that carbon losses associated with edge effect (947 Tg C) corresponded to one-third of losses from deforestation (2592 Tg C). Despite a notable negative trend of 7 Tg C year−1 in carbon losses from deforestation, the carbon losses from edge effect remained unchanged, with an average of 63 ± 8 Tg C year−1. Carbon losses caused by edge effect is thus an additional unquantified flux that can counteract carbon emissions avoided by reducing deforestation, compromising the Paris Agreement’s bold targets.

scholarly journals Approaches of Satellite Remote Sensing for the Assessment of Above-Ground Biomass across Tropical Forests: Pan-tropical to National Scales

2020 ◽  
Vol 12 (20) ◽  
pp. 3351
Author(s):  
Sawaid Abbas ◽  
Man Sing Wong ◽  
Jin Wu ◽  
Naeem Shahzad ◽  
Syed Muhammad Irteza
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Carbon Sequestration ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Satellite Remote Sensing ◽  
Forest Cover ◽  
Above Ground Biomass ◽  
Forest Cover Change ◽  
Ground Biomass

Tropical forests are acknowledged for providing important ecosystem services and are renowned as “the lungs of the planet Earth” due to their role in the exchange of gasses—particularly inhaling CO2 and breathing out O2—within the atmosphere. Overall, the forests provide 50% of the total plant biomass of the Earth, which accounts for 450–650 PgC globally. Understanding and accurate estimates of tropical forest biomass stocks are imperative in ascertaining the contribution of the tropical forests in global carbon dynamics. This article provides a review of remote-sensing-based approaches for the assessment of above-ground biomass (AGB) across the tropical forests (global to national scales), summarizes the current estimate of pan-tropical AGB, and discusses major advancements in remote-sensing-based approaches for AGB mapping. The review is based on the journal papers, books and internet resources during the 1980s to 2020. Over the past 10 years, a myriad of research has been carried out to develop methods of estimating AGB by integrating different remote sensing datasets at varying spatial scales. Relationships of biomass with canopy height and other structural attributes have developed a new paradigm of pan-tropical or global AGB estimation from space-borne satellite remote sensing. Uncertainties in mapping tropical forest cover and/or forest cover change are related to spatial resolution; definition adapted for ‘forest’ classification; the frequency of available images; cloud covers; time steps used to map forest cover change and post-deforestation land cover land use (LCLU)-type mapping. The integration of products derived from recent Synthetic Aperture Radar (SAR) and Light Detection and Ranging (LiDAR) satellite missions with conventional optical satellite images has strong potential to overcome most of these uncertainties for recent or future biomass estimates. However, it will remain a challenging task to map reference biomass stock in the 1980s and 1990s and consequently to accurately quantify the loss or gain in forest cover over the periods. Aside from these limitations, the estimation of biomass and carbon balance can be enhanced by taking account of post-deforestation forest recovery and LCLU type; land-use history; diversity of forest being recovered; variations in physical attributes of plants (e.g., tree height; diameter; and canopy spread); environmental constraints; abundance and mortalities of trees; and the age of secondary forests. New methods should consider peak carbon sink time while developing carbon sequestration models for intact or old-growth tropical forests as well as the carbon sequestration capacity of recovering forest with varying levels of floristic diversity.

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