Largest Tropical Forest Research Articles

Carbon dioxide fertilization enhanced carbon sink offset by climate change and land use in Amazonia on a centennial scale

The Amazon, the Earth's largest tropical forest, plays a critical role in the global carbon cycle, acting as a significant carbon sink. Recent studies, however, indicate a decline in its carbon sequestration capacity due to climate variability, intensive deforestation, and fires. This study aims to examine the impacts of these factors on the carbon dynamics of the Amazon over a centennial scale based on dynamic global vegetation models (DGVMs) of Trendy-v11. It was found that the Amazon region exhibited significant spatiotemporal variations in net land carbon (C) fluxes, and was a net C sink (40.02 ± 242.64 Tg C yr−1) during 1901–2021. The Amazonian net biome productivity (NBP) showed a 6-decades-scale shift from a decreasing trend (−3.78 Tg C yr−2) during 1901–1959 to an increasing trend (2.39 Tg C yr−2) during 1960–2021. The Amazonian NBP was negatively related to air temperature while positively related to dry-season precipitation during 1901–2021. Furthermore, the increase of atmospheric CO2 concentration during 1901–2020 enhanced Amazonian NBP by 36.40 ± 8.39 Pg C, which was largely offset by land use change (−18.84 ± 12.02 Pg C) and climate change (−10.03 ± 5.00 Pg C). Our findings underscore the critical need for sustainable management practices in the Amazon to enhance its C sink and preserve its function in the global climate system.

Zero deforestation and degradation in the Brazilian Amazon

Brazil’s main goal is zero deforestation and degradation (ZDD) in the Amazon. Existing policies do not consider the region’s heterogeneity. Integrated sectoral policies are necessary for consolidating sustainable subregional territories. To protect the world’s largest tropical forest while improving local people’s lives, government agencies must overcome funding shortfalls and gaps in coordination.

Evaluation of the Effectiveness of CSR Programs on Community Behavior Change in Forest Conservation

Global warming can cause climate change and have a broad impact on people's lives. The increase in global temperature is caused by increased carbon emissions due to deforestation in various countries. Forests play a very important role in solving the carbon emissions problem. One source of carbon dioxide emissions throughout the world is the existence of Tropical Forests. One of the countries that has the largest tropical forest in the world is Indonesia. Kalimantan Island is one of the largest islands and has the largest forest area in Indonesia. This research was conducted at PT. Asmin Bara Bronang who runs the company's CSR program. The variables are the implementation of CSR programs, the targets of the CSR programs implemented and their impact on changes in community behavior in forest conservation. This research also discusses the relationship between implementing CSR programs with ISO 26000 and the Sustainable Development Goals. The sampling technique used was purposive sampling. Data collection was carried out through interviews with 43 sources consisting of PT Asmin Bara Bronang employees and community recipients of the CSR program. The collected data was then analyzed using the content analysis method. Research shows PT. Asmin Bara Bronang carries out a CSR program contributes to changes in the behavior of the Dayak Ngaju community in efforts to preserve Kalimantan's forests. It is hoped that this research can complement the literature regarding the implementation of CSR programs in supporting forest conservation programs

Organic substrates in the development of camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh) in the amazon region

Amazon is the largest tropical forest on the planet, it has a variety of plant species with emphasis on manyfruit trees, such as the camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh), which occurs naturally on thebanks of rivers, lakes, lowlands and flooded forest of the Amazon. The objective of this study is to evaluate thedevelopment of camu-camuzeiro seedlings in different organic substrates. The experiment was conductedin the seedling production nursery of the Federal Rural University of Amazon. The experimental design wasentirely randomized, with ten treatments and five repetitions, each portion was represented by ten plants,totaling 500 seedlings. The substrates evaluated were: T1 - Humus; T2 - Humus + Bird manure; T3 - Humus + Bovinemanure; T4 - Humus + Açaí kernel; T5 - Humus + Chestnut shell; T6 - Humus + Chestnut shell + Poultry manure;T7 - Humus + Bovine manure + Chestnut shell; T8 - Humus + Açaí kernel + Poultry manure; T9 - Humus + Açaíkernel + Bovine manure; T10 - Commercial. The different substrates used influenced the development of camucamuzeiroseedlings evaluated at 180 days. The treatments with a substrate based on Humus (T1), Humus + Açaíkernel (T4), Humus + Chestnut shell (T5), Humus + Chestnut shell + Poultry manure (T6), Humus + Bovine manure +Chestnut shell (T7), Humus + Açaí Kernel + Bovine manure (T9) and the commercial substrate (T10) are the bestfor a satisfactory development of this crop in the production field.

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution.

Functional traits patterns along an altitudinal gradient in a large tropical forest region

Understanding the link between functional traits and environmental gradients can provide important information to face global change. Here, we assessed how environmental variables act on functional trait-based ecological strategies of the acquisitive-conservative continuum and dispersal syndromes in forests of the Rio Doce Basin in Brazil's Atlantic Forest. Through literature and herbarium measurements, we gathered data on ten functional traits related to light interception, leaf economics spectrum, and reproductive ability from 1912 woody species across 79 localities. Relationships between community-weighted means of functional traits and an altitudinal gradient encompassing thermal and water availability variables were quantified using generalized linear models and principal component analysis. We found that in higher altitudes are predominant vegetative conservative functional strategies (smaller leaves and petioles) and reproductive acquisitive functional strategies (smaller fruits and seeds and abiotic dispersed species). The thermal variables mainly influenced vegetative functional traits, which showed a predominantly acquisitive strategy in warmer areas, where there are more favorable and stable conditions for rapid growth and resource uptake. The water variables had a pronounced impact on reproductive functional traits, particularly in terms of dispersal patterns. Water availability tends to impact the costs of fleshy fruits and seeds with higher energy content. The patterns found for the altitudinal gradient reflected a combination of thermal and water variables, which is congruent with the aggregative role of altitude, composed of multiple physical and climatic conditions. In conclusion, the abiotic factors are operating on a large landscape scale in the plant communities, exerting influence on functional traits along the altitudinal gradient in a tropical forest region.

Time-series analysis of satellite imagery for detecting vegetation cover changes in Indonesia

Indonesia has one of the world’s largest tropical forests; thus, its deforestation and environmental degradation are a global concern. This study is the first to perform comprehensive big data analyses with coherent vegetation criteria to measure the vegetation change at a high temporal resolution (every 16-day period) for 20 years and the high administrative resolution (regency or city) all over Indonesia. The normalized difference vegetation index (NDVI) of the Moderate Resolution Imaging Spectroradiometer is analyzed through state space modeling. The findings reveal that the NDVI increases in almost all regencies, except in urban areas. A high correlation between the NDVI change and the time is observed in Sumatra, Papua, and Kalimantan. The gain of the NDVI values is obvious in the Central and Eastern Java Island. Human activities, such as the expansion of agriculture and forestry and forest conservation policies, are the key factors for the observed pattern.

What Can Tapir Poop Teach Us About Healthy Forests?

The Baird’s tapir is the largest land mammal living in the Mexican Selva Maya, which is the largest tropical forest in America after the Amazon. Tapirs are herbivores that play a key role in maintaining the health of tropical forests by dispersing seeds in their feces (poop). Tapirs are mysterious, silent, and nocturnal characteristics that make them difficult to study. In our research, we analyzed the microbes in tapirs’ feces to understand the health of tapir populations in the Mexican Selva Maya. We found that a large amount of variety in tapirs’ fecal microbes is associated with a healthy tropical forest ecosystem. Maybe the analysis of the fecal microbes of wildlife can be used as a gentle technique to help us understand the health status of animals and the environments in which they live.

Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, varPsi 50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3–5, little is known about how these vary across Earth’s largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters varPsi 50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both varPsi 50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth–mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.

Towards a Transnational Approach to Transboundary Haze Pollution: Governing Traditional Farming in Fire-Prone Regions of Indonesia

AbstractIn Indonesia, swidden practices have been part of traditional rice farming for centuries. Swidden agriculture is a fundamental part of all remaining large tropical forests and provides a critical form of biodiversity-friendly agriculture. Meanwhile, peatland degradation and land conversion for oil palm plantation and agriculture have created an annual transboundary environmental disaster in Southeast Asia. This article adopts a transnational lens to highlight the complex multi-scale interactions that perpetuate recurring transboundary air pollution in the region. Having examined the traditional practices of swidden agriculture in Central Kalimantan and South Sumatra (Indonesia), the article reveals that swidden agriculture has been misunderstood generally, and in particular in international and national law and policy. It argues that existing laws fail to identify the important role that swidden agriculture plays in sustainable ecosystem management and cultural expression. Nuanced understandings of fire use, alongside transnational multi-stakeholder and multi-scale approaches, are required.

Early Warning System for Fire Catcher in Rain Forest of Sumatera Using Thermal Spots

This research’s goals were clear agricultural land in large tropical forests, it is usually very difficult to control because it requires no small amount of money for farmers. The burning method of tropical forest land is a cheap way for farmers to start farming and saves energy. Unfortunately, this method can increase the impact on health and environmental damage. There are several research on burning forest land for agriculture but there are still many weaknesses and shortcomings in the application of the applied method. Therefore, a model was designed to detect and reduce the weaknesses and shortcomings of each method applied in optimizing the detection and reduction of error rates in forest burning that can cause forest fires using the 4.0 technology method. In designing of the Early Warning System Model for Fire Catcher in the rain forest of Jambi, Sumatra, the methods used are literature study, analysis method with hotspots information system (hotspots) and Earth data, NASA. The analytical method in the form of action research is intended to examine the problems faced by the Forestry Service of the Province of Sumatra and the tropical forests of Sumatra. Forestry Service Unit in Sumatra Province as a sample. The design method is used to design a new application system based on data taken from interviews with the forestry service in the form of Intellectual Property Rights that can provide solutions to problem identification. In designing the Early Warning System Model for Fire Catcher in the rain forest of Jambi, Sumatra as the outcome of the first-year research that the methods used are literature study, analysis method with hotspot information system and Earth data, NASA. The design of the Intellectual Property Rights Model uses PHP, MySQL. The result to be achieved is the success of the early warning system model to detect forest fires also the widespread publication in Indonesia in the first year of this research.

Struktur komunitas Tumbuhan Bawah di Zona Pemanfaatan Blok Ireng-Ireng Taman Nasional Bromo Tengger Semeru (TNBTS)

Indonesia is a country that has a very large tropical rain forest. The forest is a unified biological system as part of the earth there is an ordinary organic wealth covered with trees which in cooperation in their nature and current state cannot be separated. Groundcover is a basic vegetation component under forest stands other than tree rejuvenation, which consists of grasses, herbs and shrubs. Bromo Tengger Semeru National Park (TNBTS) is a conservation area with abundant biodiversity, both in terms of flora and fauna. The purpose of this study was to determine the genus of the undergrowth and dominancefound in the Ireng-Ireng Block Utilization Zone, Bromo Tengger Semeru National Park. The research method uses line and transect plots with 4 transects 20 m long, each with 5 plots measuring 1 x 1 m with a distance between plots of 3 m. Result research Found 13 genera as follows Davallia, Strychnos, Homalomena, Nheprolepis, Pheghopteris, Pteris, Ageratina, Sceleria, Molineria, Didymochlaena, Adiantum, Begonia, and Ruellia. The understorey plants that had the highest cover were from the Strychnos genus group with an important value index of 26.87 .
 
 Keywords: structure, komposition, Groundcover, ireng ireng block utilization zone Bromo Tengger Semeru National Park.

A Systematic Review of Logging Impacts in the Amazon Biome

Every year, logging in the world’s largest tropical forest, located within the Amazon biome, continues unabated. Although it is a preferred alternative to deforestation, the residual stand and site are impacted by logging. The objective of this review was to determine and assess the current state of research throughout Amazonia on the subject of logging impacts. To achieve this goal, a systematic approach was utilized to gather, assess and categorize research articles conducted in the Amazon biome over the last decade. Eligibility for inclusion of articles required demonstration of a direct impact from logging operations. A total of 121 articles were determined to meet the eligibility requirements and were included in this review. Articles were subdivided into three environmental categories: forest (n = 85), wildlife (n = 24) and streams (n = 12). The results of this review demonstrated that impacts from logging activities to the forest site were a direct result of the logging cycle (e.g., how often logging occurs) or logging intensity (e.g., how many trees are felled). The impacts to wildlife varied dependent on species, whereas impacts to streams were affected more by the logging system. Overall, research suggested that to attain sustainability and diminish the impacts from logging, a lower logging intensity of 10–15 m3 ha−1 and a longer logging cycle of 40–60 years would be essential for the long-term viability of forest management in Amazonia.

Forest loss analysis and calculation with geospatial artificial intelligence: A case study of papua province

The combination of its equatorial location and number of islands of Indonesia provides numbers of biomass storage capability, bioenergy resources and abundant natural wealth of forest, while known as home to the world's third largest tropical forest. Forest loss can cause many adverse impacts on ecosystem balance and biodiversity by changing the configuration and structure of the forest landscape. Over the last twenty years, the deforestation in Indonesia keeps increasing with uneven distribution between the western and eastern part of the country. Consistent and efficient observation of forest loss using remote sensing data provides important information for understanding the role of forest in the role of forest conversion in the global carbon cycle, biodiversity analysis, and selecting potential strategies on reducing deforestation. In this study, a Global Forest Change Datasets were utilized to analyze, calculate, and map forest loss in Papua, Indonesia from 2001 to 2021. Cloud data processing is carried out using the google earth engine to obtain the total forest loss data in district scale of Papua Province. Three indicators used in this method, the tree cover in the year of 2000 as the forest baseline, yearly forest gain (2000 - 2012), and yearly forest loss (2001 - 2021). The results of the study show that in the last two decades, Papua Province has lost 2,806% or 9.062 km2 of its forest cover area, while the semi-urban and urban areas are 2-20 times more prone to deforestation compared to the dense forest area. Although increasing each year, Papua Province has a very low threat of deforestation compared to other provinces in Indonesia. However, the anthropogenic conversion to the productive plantation site might become a significant hazard in the upcoming years, not only in urban and semi-urban area, but also in remote and dense forest areas.

The Changing Amazon Hydrological Cycle—Inferences From Over 200 Years of Tree‐Ring Oxygen Isotope Data

AbstractChanges to the Amazon hydrological cycle have important consequences for world's largest tropical forest, and the biodiversity it contains. However, a scarcity of long‐term climate data in the region makes it hard to contextualize recent observed changes in Amazon hydrology. Here, we explore to what extent tree‐ring oxygen isotope (δ18OTR) chronologies can inform us about hydrological changes in the Amazon over the past two centuries. Two δ18OTR records from northern Bolivia and the Ecuadorian Andes are presented. The Ecuador record spans 1799–2012 (n = 16 trees) and the Bolivia record spans 1860–2014 (n = 32 trees), making them the longest δ18OTR records from the Amazon, and among the most highly‐replicated δ18OTR records from the tropics to date. The two chronologies correlate well at interannual and decadal timescales, despite coming from sites more than 1,500 km apart. Both δ18OTR records are strongly related to interannual variation in Amazon River discharge measured at Óbidos, and accumulated upwind precipitation, suggesting a common climatic driver. In both records a strong increase in δ18OTR was observed up until approximately 1950, consistent with positive trends in the few other existing δ18O proxy records from across the Amazon. Considering all possible drivers of this long‐term increase, a reduction in rainout fraction over the basin driven by rising sea surface temperatures in the North Atlantic is suggested as the most likely cause. The upward trend in δ18OTR reverses over the past 1–2 decades, consistent with the observed strengthening of the Amazon hydrological cycle since approximately 1990.

The impact of species complexes on tree abundance patterns in Amazonia.

The impact of species complexes on tree abundance patterns in Amazonia.

Understanding land use change impacts on ecosystem services within urban protected areas

Protected Areas (PAs) aim at safeguarding biodiversity and cultural values by regulating land use and land cover (LULC) within their boundaries. In the context of different PAs categories, urban planners have the challenge of temporally and spatially understand ecosystem services (ES) supply and demand. To shed light on this issue, we explored ES within two levels of PAs in one of the main cities in a large tropical forest. By analyzing LULC and mapping ES in sustainable use and full protection PAs in São Paulo (Brazil), we investigated the impacts on ES supply and demand resulting from 28 years of LULC changes. In the sustainable use area, we identified urban expansion and the increased pressure on urban parks. In contrast, full protection PAs blocked the urbanization resulted from major undertakings and blocked the urban sprawl to parts of the sustainable use area. We found possible trade-offs between water provision (positively affected) and tourism (negatively affected) in response to the loss of pasture and between water provision (negatively affected) and local climate regulation, and tourism (positively affected) associated with the increase in agriculture. Our study reveals that conservation targets for PAs decisions should address trade-offs among ES as a result of LULC changes derived from surrounding projects and associated interventions.

Low N2O and variable CH4 fluxes from tropical forest soils of the Congo Basin

Globally, tropical forests are assumed to be an important source of atmospheric nitrous oxide (N2O) and sink for methane (CH4). Yet, although the Congo Basin comprises the second largest tropical forest and is considered the most pristine large basin left on Earth, in situ N2O and CH4 flux measurements are scarce. Here, we provide multi-year data derived from on-ground soil flux (n = 1558) and riverine dissolved gas concentration (n = 332) measurements spanning montane, swamp, and lowland forests. Each forest type core monitoring site was sampled at least for one hydrological year between 2016 - 2020 at a frequency of 7-14 days. We estimate a terrestrial CH4 uptake (in kg CH4-C ha−1 yr−1) for montane (−4.28) and lowland forests (−3.52) and a massive CH4 release from swamp forests (non-inundated 2.68; inundated 341). All investigated forest types were a N2O source (except for inundated swamp forest) with 0.93, 1.56, 3.5, and −0.19 kg N2O-N ha−1 yr−1 for montane, lowland, non-inundated swamp, and inundated swamp forests, respectively.

Wood-inhabiting macrofungi Hymenochaetales and Polyporales (Basidiomycota) in the Amazon Forest: relationship the abiotic factors and substrate colonization.

Hymenochaetales and Polyporales are important macrofungi for the maintenance of tropical forests, since they act directly in the nutrient cycling of the wood decomposition. In the Amazon, the largest tropical forest in the world, knowledge about Agaricomycetes is still insipient, since many areas have not yet been inventoried and new records appear each new study. To increase ecological knowledge about the Hymenochaetales and Polyporales, in the Brazilian Amazon region, collections were conducted in western Pará, Brazil, relating these fungi to the substrate they colonize and to environmental variables. 91 species were identified, with greater macrofungi richness associated with the rainy season; these fungi showed preferences for dead woods, of small diameter (class 1 = 5,9 ˫ 39 cm) and, in stages of decomposition still rigid or intermediate. The abundance and richness of Hymenochaetales and Polyporales were influenced by air humidity and the assemblage composition was influenced by temperature, air humidity and rainfall. The results indicate a rich diversity for western Pará region, these species are associated with environmental conditions, and may be threatened by the increasing pressure of human activity in the Brazilian Amazon.

Genetic structure and diversity among individuals of Copaifera langsdorffii Desf. from Mato Grosso, Brazilian Amazon, using ISSR markers

The Amazon is the largest tropical forest in the world and is home to around 20% of all the biodiversity on the planet, among the species present in the Amazon is Copaifera langsdorffii, exploited mainly for the extraction of oil-resin and wood, often in ways incorrect, which can cause the loss of genetic variability. The aim of this study was to evaluate the genetic structure and diversity among individuals of C. langsdorffii located in Mato Grosso, Brazil, using ISSR markers. We sampled leaves from 27 adult individuals of C. langsdorffii, whose total genomic DNA was extracted. A total of 12 ISSR primers were used for the molecular characterization of the individuals. A grouping analysis was performed using the unweighted pair group method, Bayesian analysis and characterized by the genetic diversity. The genetic diversity among and within the groups was demonstrated by the AMOVA. As a result, 106 fragments were amplified and 98.11% were polymorphic. The polymorphic information content of each primer ranged from 0.45 to 0.81. The dendrogram showed the formation of 4 distinct groups. The greatest genetic variability is found within the groups and not between them. The percentage of polymorphism, genetic dissimilarity values and genetic diversity indexes indicate that there is high genetic variability among Copaifera langsdorffii individuals, suggesting that ISSR primers were efficient in detecting polymorphism in this species and that the individuals have potential for compose programs aimed at the preservation of the species and the ability to integrate germplasm banks.