scholarly journals Forest aboveground biomass stock and resilience in a tropical landscape of Thailand

2019 ◽  
Author(s):  
Nidhi Jha ◽  
Nitin Kumar Tripathi ◽  
Wirong Chanthorn ◽  
Warren Brockelman ◽  
Anuttara Nathalang ◽  
...  
Keyword(s):  
Latin American ◽  
Aboveground Biomass ◽  
Laser Scanning ◽  
Secondary Forest ◽  
Recovery Process ◽  
Climatic Conditions ◽  
Forest Landscape ◽  
Secondary Forests ◽  
Forest Patches ◽  
The Mean

Abstract. Half of Asian tropical forests were disturbed in the last century resulting in the dominance of secondary forests in Southeast Asia. However, the rate at which biomass accumulates during the recovery process in these forests is poorly understood. We studied a forest landscape located in Khao Yai National Park (Thailand) that experienced strong disturbances in the last century due to clearance by swidden farmers. Combining recent field and airborne laser scanning (ALS) data, we first built a high-resolution aboveground biomass (AGB) map over 60 km2 of the forest landscape. We then used the random forest algorithm and Landsat time-series (LTS) data to classify landscape patches as non-forested versus forested on an almost annual basis from 1972 to 2017. The resulting chronosequence was then used in combination with the AGB map to estimate forest carbon recovery rates in secondary forest patches during the first 42 years of succession. The ALS-AGB model predicted AGB with an error of 14 % at 0.5-ha resolution (RMSE = 45 Mg ha−1) using the mean top-of-canopy height as a single predictor. The mean AGB over the landscape was of 291 Mg ha−1 showing a high level of carbon storage despite past disturbance history. We found that AGB recovery varies non-linearly in the first 42 years of the succession, with an increasing rate of accumulation through time. We predicted a mean AGB recovery rate of 6.9 Mg ha−1 yr−1, with a mean AGB gain of 143 and 273 Mg ha−1 after 20 and 40 years, respectively. These estimates are within the range of those reported for the well-studied Latin American secondary forests under similar climatic conditions. This study illustrates the potential of ALS data not only for scaling up field AGB measurements but also for predicting AGB recovery dynamics when combined with long-term satellite data. It also illustrates that tropical forest landscapes that were disturbed in the past are of utmost importance for the regional carbon budget and thus for implementing international programs such as REDD+.

scholarly journals Forest aboveground biomass stock and resilience in a tropical landscape of Thailand

2020 ◽  
Vol 17 (1) ◽  
pp. 121-134 ◽  
Author(s):  
Nidhi Jha ◽  
Nitin Kumar Tripathi ◽  
Wirong Chanthorn ◽  
Warren Brockelman ◽  
Anuttara Nathalang ◽  
...  
Keyword(s):  
Latin American ◽  
Aboveground Biomass ◽  
Laser Scanning ◽  
Secondary Forest ◽  
Climatic Conditions ◽  
Tropical Rainforests ◽  
Forest Landscape ◽  
Secondary Forests ◽  
Greenhouse Gas Inventories ◽  
The Mean

Abstract. Half of Asian tropical forests were disturbed in the last century resulting in the dominance of secondary forests in Southeast Asia. However, the rate at which biomass accumulates during the recovery process in these forests is poorly understood. We studied a forest landscape located in Khao Yai National Park (Thailand) that experienced strong disturbances in the last century due to clearance by swidden farmers. Combining recent field and airborne laser scanning (ALS) data, we first built a high-resolution aboveground biomass (AGB) map of over 60 km2 of forest landscape. We then used the random forest algorithm and Landsat time series (LTS) data to classify landscape patches as non-forested versus forested on an almost annual basis from 1972 to 2017. The resulting chronosequence was then used in combination with the AGB map to estimate forest carbon recovery rates in secondary forest patches during the first 42 years of succession. The ALS-AGB model predicted AGB with an error of 14 % at 0.5 ha resolution (RMSE=45 Mg ha−1) using the mean top-of-canopy height as a single predictor. The mean AGB over the landscape was 291 Mg ha−1, showing a high level of carbon storage despite past disturbance history. We found that AGB recovery varies non-linearly in the first 42 years of the succession, with an increasing rate of accumulation through time. We predicted a mean AGB recovery rate of 6.9 Mgha-1yr-1, with a mean AGB gain of 143 and 273 Mg ha−1 after 20 and 40 years, respectively. This rate estimate is about 50 % larger than the rate prescribed for young secondary Asian tropical rainforests in the 2019 refinement of the 2006 IPCC guidelines for national greenhouse gas inventories. Our study hence suggests that the new IPCC rates, which were based on limited data from Asian tropical rainforests, strongly underestimate the carbon potential of forest regrowth in tropical Asia. Our recovery estimates are also within the range of those reported for the well-studied Latin American secondary forests under similar climatic conditions. This study illustrates the potential of ALS data not only for scaling up field AGB measurements but also for predicting AGB recovery dynamics when combined with long-term satellite data. It also illustrates that tropical forest landscapes that were disturbed in the past are of utmost importance for the regional carbon budget and thus for implementing international programs such as REDD+.

scholarly journals Landscape structure shapes the diversity of tree seedlings at multiple spatial scales in a fragmented tropical rainforest

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253284
Author(s):  
Sergio Nicasio-Arzeta ◽  
Isela E. Zermeño-Hernández ◽  
Susana Maza-Villalobos ◽  
Julieta Benítez-Malvido
Keyword(s):  
Landscape Structure ◽  
Secondary Forest ◽  
Spatial Scales ◽  
Landscape Composition ◽  
Landscape Configuration ◽  
Secondary Forests ◽  
Tree Seedling ◽  
Forest Patches ◽  
Β Diversity ◽  
Α Diversity

The maintenance of seedling diversity of animal-dispersed tree species is fundamental for the structure and function of forest patches in fragmented tropical rainforests. Nonetheless, the effects of landscape structure at different spatial scales on α- and β-diversity of tree seedling communities are recently explored. Using a multi-scale approach, we assessed the relative effect of landscape composition and configuration on α- and β-diversity of animal-dispersed seedlings within 16 forest patches in the Lacandona rainforest, Mexico. We assessed these effects at 13 spatial scales (from 300 to 1500 m radius, at 100 m intervals) for three metrics of effective number of species considering α- and β-diversity. We found that α-diversity was largely affected by landscape composition and β-diversity by landscape configuration. On the one hand, the amount of secondary forest influenced α-diversity. Additionally, species richness increased in landscapes with highly aggregated forest patches. On the other hand, β-diversity was affected positively by forest fragmentation and negatively by the edge contrast of forest patches with the surrounding matrix. Our findings indicate that landscape configuration is a strong driver of seedling diversity in highly deforested rainforests. Promoting forest patches and secondary forests through payment for ecosystem services’ programs, favoring matrix quality within land-sharing schemes of smallholder agriculture and secondary forest management, and identifying restoration opportunities for assisted or unassisted natural regeneration are urgently needed for conservation of seedling diversity in human-modified tropical landscapes.

scholarly journals Bee diversity in secondary forests and coffee plantations in a transition between foothills and highlands in the Guatemalan Pacific Coast

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9257
Author(s):  
Gabriela Armas-Quiñonez ◽  
Ricardo Ayala-Barajas ◽  
Carlos Avendaño-Mendoza ◽  
Roberto Lindig-Cisneros ◽  
Ek del-Val
Keyword(s):  
Latin American ◽  
Secondary Forest ◽  
Vegetation Type ◽  
Dry Season ◽  
Secondary Forests ◽  
Coffee Production ◽  
Forest Protection ◽  
Coffee Plantations ◽  
Pollinator Diversity ◽  
Bee Diversity

Background Although conservation of pristine habitats is recognized in many countries as crucial for maintaining pollinator diversity, the contribution of secondary forest conservation is poorly recognized in the Latin American context, such as in Guatemala. San Lucas Tolimán (SLT) is a high-quality coffee production region from the Atitlan Province, which has the second highest deciduous forest cover in Guatemala and pristine forest is prioritized for conservation. In contrast, secondary forest protection is undetermined, since these forests are normally removed or strongly affected by coffee farming practices. This situation may affect the diversity of native pollinators, mainly bees, which usually rely on the secondary forest for food resources. Methods We conducted a study to investigate the importance of secondary forests around the SLT coffee plantations (Coffea arabica L.) for pollinators. We compared bee diversity (richness, abundance and composition) in secondary forests of different age and coffee plantations with diverse farming techniques. Being the first study of pollinators in Guatemalan coffee plantations, we also recorded data for an entire year (2013–2014) in order to describe bee seasonality. Results We found significant differences in bee diversity between the coffee plantations and secondary forests, particularly early secondary forests showed higher bee abundances but diversity indices were similar between different vegetation type plots. In the early dry season, secondary forests showed the greatest native bee diversity. During the late dry season, when the coffee was flowering, honey bees were dominant in the same plots. This study provides important management insights to support the conservation of pollinators, since our results offer guidelines to improve coffee production by increasing native pollinator diversity.

scholarly journals Home range and habitat use by pacas in a montane tropical forest in Bolivia

2017 ◽  
Vol 47 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Camila BENAVIDES ◽  
Alejandro ARCE ◽  
Luis F. PACHECO
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Secondary Forest ◽  
Agroforestry Systems ◽  
Minimum Convex Polygon ◽  
Forest Patches ◽  
La Paz ◽  
Agricultural Community ◽  
The Mean ◽  
Montane Tropical Forest

ABSTRACT We studied the home range and habitat use of paca (Cuniculus paca) in a rural agricultural community in the Alto Beni region, in La Paz department, Bolivia, where game meat is the main source of protein for a large portion of local inhabitants. We captured and radio collared five individual paca (4 females and 1 male), which were followed for six months in 2012 to estimate home range of the individuals and assess their habitat use and selection. The total mean home range (95% Minimum Convex Polygon) was 2.26 ha (SD = 0.80), and ranged from 1.5 to 2.96 ha. The mean female home range (2.04 ha) was smaller than the male´s (2.95 ha). Pacas used two (crops and fallows) of the three available habitats (secondary forest patches), and appeared to positively select crops over the other two. The importance of crops may be linked to the type of agriculture conducted in the area (i.e. mainly cacao in agroforestry systems), which may offer more food and shelter for pacas. Given that, the importance of habitats may change seasonally; this topic should be examined in future studies. Our results suggest that agroforestry systems may be important for the species since they offer a variety of food resources throughout the year.

scholarly journals Human Activity and Forest Degradation Threaten Populations of the Nigeria–Cameroon Chimpanzee (Pan troglodytes ellioti) in Western Cameroon

2021 ◽  
Vol 42 (1) ◽  
pp. 105-129
Author(s):  
Chefor Fotang ◽  
Udo Bröring ◽  
Christian Roos ◽  
Evidence Chinedu Enoguanbhor ◽  
Ekwoge E. Abwe ◽  
...  
Keyword(s):  
Human Activity ◽  
Pan Troglodytes ◽  
Distance Sampling ◽  
Forest Degradation ◽  
Edge Length ◽  
Encounter Rate ◽  
Secondary Forests ◽  
Forest Patches ◽  
The Mean ◽  
Pan Troglodytes Ellioti

AbstractIncreased human activities such as commodity-led deforestation, extension of agriculture, urbanization, and wildfires are major drivers of forest loss worldwide. In Cameroon, these activities cause a loss of suitable primate habitat and could ultimately threaten the survival of chimpanzees (Pan troglodytes). We derived independent estimates of the population size of the Endangered Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) in Kom-Wum Forest Reserve, Cameroon, and surrounding unprotected forest areas through 1) direct observations, 2) camera trapping, 3) distance sampling, 4) marked nest counts, and 5) standing crop nest counts. In addition, we georeferenced signs of chimpanzee and human activity along line transects. We used a generalized linear mixed model to predict the occurrence of chimpanzees in response to edge length (measured as the perimeter of core forest patches), core area of forest patches (measured as area of forest patches beyond an edge width of 100 m), habitat perforation (measured as the perimeter of nonforested landscape within core forest patches), patch size(measured as area of forest patches), and forest cover. Chimpanzee density estimates ranged from 0.1 (direct observation) to 0.9 (distance sampling) individuals km−2 depending on estimation method with a mean nest group size of 7 ± 5.4 (SD). The mean encounter rate for signs of chimpanzee activity was significantly higher in mature forests (2.3 signs km−1) than in secondary forests (0.3 signs km−1) and above 1000 m elevation (4.0 signs km−1) than below 1000 m (1.0 signs km−1). The mean encounter rate for signs of human activity was significantly higher in secondary (8.0 signs km−1) than in mature forests (0.9 signs km−1). Secondary forests, habitat perforation, and edge length had a significant negative effect on the occurrence of chimpanzee signs. Overall, human activity and forest degradation affected the number of observed chimpanzee signs negatively. Regular antipoaching patrols and reforestation programs in degraded areas could potentially reduce threats to populations of endangered species and may increase suitable habitat area.

scholarly journals RAIN INTERCEPTION IN A SECONDARY FRAGMENT OF ARAUCARIA FOREST WITH FAXINAL, GUARAPUAVA-PR

CERNE ◽  
2015 ◽  
Vol 21 (3) ◽  
pp. 363-369 ◽  
Author(s):  
Edivaldo Lopes Thomaz ◽  
Valdemir Antoneli
Keyword(s):  
Secondary Forest ◽  
Secondary Forests ◽  
Rainfall Events ◽  
Hydrologic Processes ◽  
Rain Gauges ◽  
South Central ◽  
The Mean ◽  
Specific Number ◽  
Vegetation Layer ◽  
Rain Interception

ABSTRACT Forest management can alter the structure of vegetation (layer), particularly in areas used for pasture, such as the Faxinal areas in the south central region of Paraná, Brazil. Therefore, the aims of the present study were as follows: a) to assess rain interception in secondary forests; b) to estimate the maximum precipitation intercepted by the forest; and c) to discuss the possible implications of throughfall for the hydrologic processes of the secondary forest (Faxinal). Nine 20-cm-diameter rain gauges (314 cm2) were used. Rain gauges were distributed randomly throughout the forest and were successively rotated after a specific number of rainfalls. A total of 66 rainfall events of different volumes were recorded. We observed that an increase in rain volume tended to homogenize the rainfall interception rate in the forest. Consecutive rainfalls did not significantly influence the interception rate in the secondary forest. However, the interception in the secondary forest (10.5%) was lower than the mean interception rate recorded in other Brazilian forests.

scholarly journals Retrieving Secondary Forest Aboveground Biomass from Polarimetric ALOS-2 PALSAR-2 Data in the Brazilian Amazon

2018 ◽  
Author(s):  
Henrique Luis Godinho Cassol ◽  
Yosio Edemir Shimabukuro ◽  
Elisabete Caria Moraes ◽  
João Manuel de Brito Carreiras ◽  
Luiz Eduardo de Oliveira Cruz e Aragão ◽  
...  
Keyword(s):  
Land Use ◽  
Secondary Forest ◽  
Cloud Model ◽  
Brazilian Amazon ◽  
Climatic Conditions ◽  
Secondary Forests ◽  
Remotely Sensed Data ◽  
The Past ◽  
Multiple Prediction ◽  
Past Land Use

Secondary forests (SF) are important carbon sinks, removing CO2 from the atmosphere through the photosynthesis process and storing photosynthates in their aboveground live biomass (AGB). This process occurring at large-scales partially counteracts C emissions from land-use change, playing, hence, an important role in the global carbon cycle. The absorption rates of carbon in these forests depend on forest physiology, controlled by environmental and climatic conditions as well as on the past land use, which is rarely considered for retrieving AGB from remotely sensed data. In this context, the main goal of this study is to evaluate the potential of full polarimetric ALOS-2 PALSAR-2 data for estimating AGB by taking into account the past-land use of SF areas in the Brazilian Amazon. We surveyed a chronosequence of 42 SF plots (20 ha) near the Tapajós National Forest in Pará state to quantifying AGB growth rates. We explored the full polarimetric data testing three regression models including non-linear (NL), multiple linear regressions models (MLR), and the semi-empirical extended water cloud model (EWCM). The results showed that the intensity of previous use has affected the structure of SF by reducing the AGB accumulation and being noticeable by several polarimetric attributes. The combination of multiple prediction variables with MLR improved the AGB estimation by 70% comparing amongst other models (R² adj. = 0.51; RMSE = 13.2 Mg ha-1) bias = 2.1 ± 37.9 Mg ha-1. The error propagation of the MLR model was estimated to be 15%.

scholarly journals POPULASI CACING TANAH PADA BERBAGAI KUALITAS SERESAH (C, N, C/N, LIGNIN, DAN POLYPHENOL) (Studi kasus pada lahan Agroforestry di Taman Nasional Kelimutu, Kabupaten Ende)

AGRICA ◽  
2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Agustinus JP Ana Saga
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Secondary Forest ◽  
Agroforestry Systems ◽  
Secondary Forests ◽  
Vegetable Crops ◽  
Polyphenol Content ◽  
Earthworm Biomass ◽  
The Mean

Population of the Earthworm on Various Litters Quality (C, N, C / N, Lignin, and Polyphenol) (Case study on Agroforestry Field in Kelimutu National Park, Ende Regency).  This study aims to evaluate the population of earthworms and the quality of plant organic matter in various agroforestry systems, intensive agriculture and secondary forests. Taking samples of plant organic matter and earthworms conducted in January - July 2016 (in the rainy season) on the land Agroforestry : Clove (AF – CK), Cocoa (AF – KK), candlenut (AF – KM, cofee (AF – KP) compared to intensive farmland (monoculture vegetable crops) and secondary forest (SPL - HS), with 3 x replications. The observed variables in addition to the number of earthworms found and the monolith sampling, also observed the quality of plant organic matter (C (Walkley and black), N (Kjehldahl), Lignin, and Polyphenol (Goering and Van Soest)) (Kuadran).         Survey results showed that the earthworm population in SPL-AF was as low as the population in SPL-HS, averaging 3 m - 2, while in SPL - PI averaged only 0.24 m -2. The earthworm biomass in AF is about 69% smaller than the worms found in SPL - HS; average earthworm biomass in SPL - AF 15 g m - 2 whereas in SPL - HS averaged 47 g m - 2; and the smallest worm biomass found in SPL-PI averaged about 2.3 g m-2. The average quality of organic matter of C - org plants in all SPL was 38% to 50%, the highest C - org levels of AF - CK, AF - KP and SPL - HS were significantly different (p <0.05) with C (an average of 39%). Levels of N and lignin levels of all plant organic matter were equal (P> 0.05), the mean of each were 1.36% and 41.13% respectively. C / N ratio in AF - CK and HS was the average of 52.78% or 58 times higher than AF - KK, AF - KM, and AF - KP, the mean of 31.11% Polyphenolic content of different plant organic matter real (p <0.05) between SPL. The largest polyphenol content of 17.5% is found in organic material of plant AF - CK and SPL - HS, while the organic material of the plants on other land is on average 3,4%. Organic plant material with polyphenol content> 2% will be slow weathered.

scholarly journals The Effect of Synergistic Approaches of Features and Ensemble Learning Algorith on Aboveground Biomass Estimation of Natural Secondary Forests Based on ALS and Landsat 8

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5974
Author(s):  
Chunyu Du ◽  
Wenyi Fan ◽  
Ye Ma ◽  
Hung-Il Jin ◽  
Zhen Zhen
Keyword(s):  
Machine Learning ◽  
Ensemble Learning ◽  
Aboveground Biomass ◽  
Laser Scanning ◽  
Learning Algorithms ◽  
Machine Learning Algorithms ◽  
Biomass Estimation ◽  
Landsat 8 ◽  
Secondary Forests ◽  
Two Factors

Although the combination of Airborne Laser Scanning (ALS) data and optical imagery and machine learning algorithms were proved to improve the estimation of aboveground biomass (AGB), the synergistic approaches of different data and ensemble learning algorithms have not been fully investigated, especially for natural secondary forests (NSFs) with complex structures. This study aimed to explore the effects of the two factors on AGB estimation of NSFs based on ALS data and Landsat 8 imagery. The synergistic method of extracting novel features (i.e., COLI1 and COLI2) using optimal Landsat 8 features and the best-performing ALS feature (i.e., elevation mean) yielded higher accuracy of AGB estimation than either optical-only or ALS-only features. However, both of them failed to improve the accuracy compared to the simple combination of the untransformed features that generated them. The convolutional neural networks (CNN) model was much superior to other classic machine learning algorithms no matter of features. The stacked generalization (SG) algorithms, a kind of ensemble learning algorithms, greatly improved the accuracies compared to the corresponding base model, and the SG with the CNN meta-model performed best. This study provides technical support for a wall-to-wall AGB mapping of NSFs of northeastern China using efficient features and algorithms.

scholarly journals Long-term monitoring reveals an avian species credit in secondary forest patches of Costa Rica

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3539 ◽  
Author(s):  
Steven C. Latta ◽  
Nathan L. Brouwer ◽  
Alison Olivieri ◽  
Julie Girard-Woolley ◽  
Judy F. Richardson
Keyword(s):  
Costa Rica ◽  
Secondary Forest ◽  
Bird Community ◽  
Safety Net ◽  
Primary Forest ◽  
Secondary Forests ◽  
Forest Species ◽  
Forest Patches ◽  
Permanent Resident ◽  
Over Time

Degraded and secondary forests comprise approximately 50% of remaining tropical forest. Bird community characteristics and population trends in secondary forests are infrequently studied, but secondary forest may serve as a “safety net” for tropical biodiversity. Less understood is the occurrence of time-delayed, community-level dynamics such as an extinction debt of specialist species or a species credit resulting from the recolonization of forest patches by extirpated species. We sought to elucidate patterns and magnitudes of temporal change in avian communities in secondary forest patches in Southern Costa Rica biannually over a 10 year period during the late breeding season and mid-winter. We classified birds caught in mist nets or recorded in point counts by residency status, and further grouped them based on preferred habitat, sensitivity to disturbance, conservation priority, foraging guild, and foraging strata. Using hierarchical, mixed-effects models we tested for trends among species that share traits. We found that permanent-resident species increased over time relative to migrants. In both seasons, primary forest species generally increased while species typical of secondary forest, scrub, or edge declined. Species relatively sensitive to habitat disturbance increased significantly over time, whereas birds less sensitive to disturbance decreased. Similarly, generalists with higher habitat breadth scores declined. Because, we found very few changes in vegetation characteristics in secondary forest patches, shifts in the avian community toward primary forest species represent a species credit and are likely related to vegetation changes in the broader landscape. We suggest that natural regeneration and maturation of secondary forests should be recognized as a positive conservation development of potential benefit even to species typical of primary forest.

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