Deforestation Scenarios Research Articles

Polypore fungus beetles (Coleoptera: Tetratomidae) in a remnant of semi-deciduous forest of the Brazilian Cerrado: checklist and the description of a new species of Eustrophopsis Champion, 1889

Tetratomidae Billberg, 1820 is a small family of tenebrionoid beetles that primarily feed on polypore fungi. Their Neotropical diversity remains poorly known, with most recent studies concentrating on Nearctic and Palearctic species. The few records from the neotropics are from samplings in the Atlantic Forest or Amazon Rainforest. Here we present illustrations of genitalia and photos of two species of Eustrophopsis Champion, 1889, E. laurae sp. nov. and E. bilunulata Pic, 1912. The samplings were carried out with malaise traps in the Parque Estadual Altamiro de Moura Pacheco (PEAMP), Goiás, Brazil, a remnant Cerrado mostly covered by semi-deciduous forest. These species represent the first records of Tetratomidae for the Brazilian Cerrado since their original descriptions, elucidating the paucity of studies on the fauna of Coleoptera in Brazil. This research is part of our ongoing efforts to better understand the insect diversity of this region, especially in current scenarios of rapid deforestation and biodiversity loss.

Implications of landscape changes for ecosystem services and biodiversity: A national assessment in Ecuador

Ecuadorian ecosystems experience high pressure due to anthropogenic activities and climate change. Despite the need of regular monitoring of biodiversity and ecosystem services (BES), attempts to assess the current and future interdependencies of BES and landscape changes are still lacking. This study suggests a spatial assessment of the capacity of ecosystems/land use types to provide BES as status quo and its future development under scenarios of deforestation and climate change. To address data scarcity and improve legitimacy, spatial modeling was combined with participatory approaches. Specifically, changes in landscape pattern were simulated using a modeling platform that combines Geographic Information System (GIS) and Cellular Automaton (CA) modules. Experts in ecosystem conservation and management participated through surveys and workshops. Food, drinking water, service water, soil erosion control, water flow regulation, pollination/seed dispersal, regulation of macro climate, and landscape aesthetic/amenity were identified as the most relevant ES. Among the forest ecosystems, Páramo-related ecosystems were regarded to provide multiple ES with high capacities. Compared to the current status, the deforestation scenario showed to decrease most BES by 20–25 %, while increasing food provision by 5 %, as a trade-off. Regarding the climate change scenarios, the “Representative Concentration Pathways” (RCP) by 2070 were simulated with an increase in temperature of 2 °C (RCP 2.6) and of 4 °C (RCP 6.0). RCP 6.0 showed more noticeable impact than RCP 2.6, which caused a decrease in most BES whereas an increase in food provision due to the possible expansion of arable land into higher altitudes. The results of the spatial assessment also indicated high and low potential areas for BES provision. Such information can support decision-making for BES management e.g., priority areas for actions. Furthermore, the applied spatially explicit assessment could be a starting point for a regular assessment of BES, which has not yet been implemented in Ecuador.

Employing scientific evidence through synthetic indices to support management and conservation policies for an endangered tree of the Gran Chaco

Management and conservation programs require accessible scientific evidence to effectively plan and achieve their goals. Facing regional and species-specific threats, Gonopterodendron sarmientoi, an endangered tree native to the Gran Chaco region, requires scientific evidence to support management and conservation actions, notably in forest management and territorial planning. To bridge this crucial gap, we developed indices that integrate genetic, evolutionary, morphological, threat-related, and ethnobotanical data concerning G. sarmientoi at a landscape level. Across twenty-four localities of this species, we have created four distinct indices. The first index amalgamates data on genetics, functional traits, and paleoclimate information. The second index incorporates data on threats stemming from deforestation and climate change scenarios. The third index provides supplementary insights into the species’ utilization by indigenous groups. Finally, the fourth index combines all the aforementioned data to prioritize the most valuable and threatened localities. Through this comprehensive approach, we have identified specific in-situ and ex-situ management and conservation actions for G. sarmientoi. This approach considers broader-scale conservation efforts and considers large-scale variations and processes. The indices effectively link scientific data with actionable insights, providing decision-makers involved with G. sarmientoi with concise information that encapsulates the most pertinent aspects of species conservation.

Effects of urbanization and deforestation on flooding: Case study of Cap‐Haïtien City, Haiti

AbstractCap‐Haïtien, the second largest city in Haiti, is highly vulnerable to earthquakes, landslides, and flooding. The rapid pace of urbanization and deforestation has exacerbated the risk of flooding, resulting in disasters in November 2012, 2016, and 2022. This study aims to assess the impact of urbanization and deforestation on river flooding in Cap‐Haïtien by applying the hydrological model Soil Water Assessment Tool (SWAT) and the hydrodynamic model Sobek‐Rural. We examined the current situation and a scenario of future urbanization and deforestation. Urbanization and deforestation are found to play a pivotal role in the production and deposition of sediment along the lower Haut‐du‐Cap River reaches. The existing hydraulic capacity of the river and its drainage system cannot handle the estimated peak flows. The mountain ravines west of the city are found to be the primary source of sediment‐laden flash floods. We recommend retention basins, drainage extensions, and pragmatic public policies to mitigate flood risk. Comprehensive strategies are needed to address the detrimental effects of urbanization and deforestation on flooding in Cap‐Haïtien and similar regions where a lack of water governance has worsened the flooding alongside urbanization and deforestation. We generalize our experiences from Cap‐Haïtien into a broader framework for data‐scarce areas.

Future Risk and Its Impact on Orangutan Habitat in Katingan-Kahayan Corridor, Central Kalimantan

The Katingan-Kahayan Corridor is currently one of the remaining habitats for Pongo pygmaeus wurmbii in Central Kalimantan, likely to be managed as an Essential Ecosystem Area. This area faces a high risk of deforestation in the future, as it is located outside protected or conservation zones. This study aims to project future deforestation in the Katingan-Kahayan Corridor from 2019 to 2050 and model its impact on orangutan habitat under two scenarios: (1) Business-as-Usual (BAU), and (2) implementation of an Essential Ecosystem Area (EEA). The deforestation risk model was built using the Random Forest Regression algorithm, while the orangutan habitat model was run using Maxent. The results of the deforestation projection model based on the two scenarios showed that by 2050, the Katingan Forest will become an isolated orangutan habitat with almost no connectivity to other large habitats around it. The secondary forest mosaic in the north of the Katingan Forest was likely to become highly vulnerable to deforestation and thus needs to be a conservation priority. The BAU deforestation scenario projected a decrease in the orangutan population in the Katingan-Kahayan Corridor by up to 68% by 2050, while the EEA implementation scenario can reduce the potential for population decline to 35%.

Effects of Deforestation and Anthropogenic Aspects on Streamflow in the Mau Forest Catchments in Kenya: Hydrological Modelling of Surface Water Yields from Sondu River Basin

Climatic factors determine the amount and distribution of atmospheric water received at the land surface while the land cover conditions determine the partitioning of this water into different hydrological components and ultimately the catchment surface water yields. This study assessed the effects of deforestation of a tropical catchment on surface water yields to address fluctuating flows of the rivers emanating from Mau Forest, the largest water tower in Kenya. Sondu basin traverses Southwest Mau Forest covering an area of 3500 km2. The main channel in the basin flows in a southwest direction into Lake Victoria in an altitudinal range of 2900 to 1130 m a.s.l over a length of 173 km. Different deforestation scenarios over the basin were integrated with climate data to form inputs to a hydrologic model, Soil and Water Assessment Tool (SWAT). Using model outputs, the effects of deforestation on annual and seasonal surface water yields, represented by changes in streamflow volumes under different deforestation scenarios, were evaluated. Deforestation scenarios were derived from a supervised classification scheme of time series of LANDSAT images (1970-2020) to show deforestation trends. Effects of deforestation on the catchment water-yielding capacity were estimated as the ratio of the difference between simulated yields under different deforestation scenarios and those simulated under the pre-deforestation scenario of the 1970s decade. Results show that forest cover declined by 21% and a corresponding growth in land under agriculture by 26% in the period 1970-2020. The decline in forest coverage resulted in an increase in the annual surface water yields of about 23% (from 152 to 187 MCM/year) throughout the period of study. This implies that there is less recharge of groundwater due to decreased infiltration and subsequent storage leading to lower flows during the dry seasons and increased flood frequencies in the basin during the wet seasons. The study has therefore, demonstrated that deforestation has reduced the stability of Mau Forest as a water tower and conservation of the forest will enhance its water-holding capacity thereby ensuring a stable water supply to rivers emanating from it as a way of combating floods and low flows in the basin. The resultant impacts on environment and society are displacements from floods and destruction of properties.

Forest cover percentage drives the peak biting time of Nyssorhynchus darlingi (Diptera: Culicidae) in the Brazilian Amazon

BackgroundDeforestation is an important driver of malaria dynamics, with a relevant impact on mosquito ecology, including larval habitat availability, blood-feeding behaviour, and peak biting time. The latter is one of several entomological metrics to evaluate vectorial capacity and effectiveness of disease control. This study aimed to test the effect of forest cover percentage on the peak biting time of Plasmodium-uninfected and infected Nyssorhynchus darlingi females.MethodsMosquitoes were captured utilizing human landing catch (HLC) in the peridomestic habitat in field collections carried out in the wet, wet-dry transition, and dry seasons from 2014 to 2017 in areas with active malaria transmission in Amazonian Brazil. The study locations were in rural settlements in areas with the mean annual malaria parasite incidence (Annual Parasite Incidence, API ≥ 30). All Ny. darlingi females were tested for Plasmodium spp. infection using real time PCR technique. Forest cover percentage was calculated for each collection site using QGIS v. 2.8 and was categorized in three distinct deforestation scenarios: (1) degraded, < 30% forest cover, (2) intermediate, 30–70% forest cover, and (3) preserved, > 70% forest cover.ResultsThe highest number of uninfected female Ny. darlingi was found in degraded landscape-sites with forest cover < 30% in any peak biting time between 18:00 and 0:00. Partially degraded landscape-sites, with (30–70%) forest cover, showed the highest number of vivax-infected females, with a peak biting time of 21:00–23:00. The number of P. falciparum-infected mosquitoes was highest in preserved sites with > 70% forest cover, a peak biting at 19:00–20:00, and in sites with 30–70% forest cover at 22:00–23:00.ConclusionsResults of this study show empirically that degraded landscapes favour uninfected Ny. darlingi with a peak biting time at dusk (18:00–19:00), whereas partially degraded landscapes affect the behaviour of Plasmodium-infected Ny. darlingi by shifting its peak biting time towards hours after dark (21:00–23:00). In preserved sites, Plasmodium-infected Ny. darlingi bite around dusk (18:00–19:00) and shortly after (19:00–20:00).

Estimating components of the hydrological cycle in the Atlantic Forest Biome using the INLAND surface model

ABSTRACT The Atlantic Forest biome has lost a significant portion of its natural habitat and little research has studied how deforestation impacts the biome’s local water balance. The objective of this research is to understand how the hydrological cycle of the region is affected by the change in land use. For this, the INLAND (Integrated Model of Surface Processes) surface model was calibrated and validated for the biome. Subsequently, changes in precipitation in the biome and the influence of deforestation on the surface components of the hydrological cycle were analyzed. To determine the influence of deforestation on the surface components of the hydrological cycle, two scenarios were simulated and compared, a deforestation scenario and a pasture scenario. The results showed that the total runoff in the deforestation scenario between 1951–1960 was, on average, 16.82% lower than the values found from 1971 to 1980. The use of modeling also made it possible to estimate the behavior of the difference between evapotranspiration and total runoff simulated with the occurrence of deforestation and with the area preserved in its entirety. It was observed that the biome has a certain resilience to deforestation up to a particular point, after which evapotranspiration decreases and the total runoff increases.

The Role of Greenhouse Gases, Aerosols, and Deforestation in Climate Change: a Multidisciplinary Assessment of the Interaction Mechanisms Between Human Activity and the Environment

Climate change can be caused by various anthropogenic or natural factors that influence atmospheric changes. The direct link between human activity and the environment is represented by the interaction mechanisms between anthropogenic factors such as urbanization, deforestation, hydrological changes, greenhouse gases and aerosols. These interaction mechanisms are assessed by the current state of knowledge in the climate change field. One of these mechanisms is related to greenhouse gases (GHGs), which increase surface level heating and lowers atmospheric temperature in the long term by increasing atmospheric GHG concentration. This heating reduces air density parcel and increases total evaporation to transfer excess heat from surface (latent heat) to atmosphere. Another mechanism is related to anthropogenic aerosols, which have direct and indirect effects on climate change with variable direct radiative forcing depending on the nature, density and composition of the aerosol particles. Anthropogenic sulphate is the main element that influences atmospheric conditions through its direct and indirect effects, which delay global warming by increasing the albedo and the lifetime of clouds formed by water droplets. A third mechanism is related to deforestation, which affects the environment according to the results of climate models based on deforestation scenarios. Deforestation alters the heat exchange between the oceans (relatively warm) and the atmosphere (relatively cold), generating a sensible heat flux (warming) that influences neighbouring regions. Deforestation also lowers surface temperature by changing coniferous vegetation to tundra and desert, causing a cooling of up to -4°C in North America and -6°C in Siberia. In Europe, deforestation scenarios show a decrease in surface temperature of -2°C to -3°C in spring and -1°C in summer in northern mid-latitudes, mainly due to the delayed melting of spring snow.

Two centuries of biodiversity discovery and loss in Singapore.

There is an urgent need for reliable data on the impacts of deforestation on tropical biodiversity. The city-state of Singapore has one of the most detailed biodiversity records in the tropics, dating back to the turn of the 19th century. In 1819, Singapore was almost entirely covered in primary forest, but this has since been largely cleared. We compiled more than 200 y of records for 10 major taxonomic groups in Singapore (>50,000 individual records; >3,000 species), and we estimated extinction rates using recently developed and novel statistical models that account for "dark extinctions," i.e., extinctions of undiscovered species. The estimated overall extinction rate was 37% (95% CI [31 to 42%]). Extrapolating our Singapore observations to a future business-as-usual deforestation scenario for Southeast Asia suggests that 18% (95% CI [16 to 22%]) of species will be lost regionally by 2100. Our extinction estimates for Singapore and Southeast Asia are a factor of two lower than previous estimates that also attempted to account for dark extinctions. However, we caution that particular groups such as large mammals, forest-dependent birds, orchids, and butterflies are disproportionately vulnerable.

Impact of land-use change on karst spring response by integration of surface processes in karst hydrology: The ISPEEKH model

Karst groundwater represents a source of freshwater for a quarter of the world's population. Modeling the hydrological behavior of karst aquifers while accounting for the spatial variability of the recharge processes and the land-use change impacts on water availability remains a challenge for karst water resources management. Therefore, this study proposes a new semi-distributed hydrological model named Integration of Surface ProcEssEs in Karst Hydrology (ISPEEKH) for simulating the surface-underground water flows in karst-dominated catchments. ISPEEKH couples the restructured version of the Soil and Water Assessment Tool (SWAT+) with a non-linear three-reservoir groundwater model that represents the epikarst and matrix-conduit flow components in a karst aquifer. ISPEEKH was applied to the Baget karst catchment (13.25 km2) in the Pyrénées mountains of southwest France, characterized by a conduit-dominated spring flow and low surface runoff. The model simulated the catchment daily discharge satisfactorily, with NSE = 0.67 and R2 = 0.68 for the 2008–2013 calibration period, and NSE = 0.65 and R2 = 0.69 for the 2014–2018 validation period. The catchment evapotranspiration and discharge amounted to 33 % and 67 % of the average annual precipitation, respectively, and nearly 80 % of the discharge was attributed to spring flow. The matrix-to-conduit flow accounted for 4–7 % of the monthly spring flow during the high-flow period (December to June), and up to 22 % during the low-flow period (July to October). ISPEEKH was then used to assess the hydrological response of the Baget catchment to land-use change scenarios of afforestation and deforestation for wood production and pasture development. Afforestation of the full catchment area did not alter the catchment hydrology significantly. Deforestation for wood production reduced annual evapotranspiration by 12–18 % and increased annual recharge by 7–8 %, resulting in annual discharge rising by 6–9 %. These changes in the water balance components were most noticeable during the low-flow season and would augment freshwater availability. Conversely, deforestation for pasture development raised annual evapotranspiration by 13–17 % while reducing annual recharge by around 7 % and discharge by 5–7 %. These changes in the hydrological components were most remarkable during the high-flow season and affected discharge below 2.5 m3.s−1.

Amazon deforestation: simulated impact of Brazil's proposed BR-319 highway project.

The scenario of deforestation in the Amazon may change with the reconstruction of Highway BR-319, a long-distance road that will expand the region's agricultural frontier towards the north and west of the Western Amazon, stretches that until then have extensive areas of primary forest due to the hard access. We simulate the deforestation that would be caused by the reconstruction and paving of Highway BR-319 in Brazil's state of Amazonas for the period from 2021 to 2100. The scenarios were based on the historical dynamics of deforestation in the state of Amazonas (business as usual, or BAU). Two deforestation scenarios were developed: (a) BAU_1, where Highway BR-319 is not reconstructed, maintaining its current status, and (b) BAU_2, where the reconstruction and paving of the highway will take place in 2025, favoring the advance of the deforestation frontier to the northern and western portion of the state of Amazonas. In the scenario where the highway reconstruction is foreseen (BAU_2), the results show that deforestation increased by 60% by 2100 compared to the scenario without reconstruction (BAU_1), demonstrating that paving would increase deforestation beyond the limits of the highway's official buffer area (40 km). The study showed that protected areas (conservation units and indigenous lands) help to maintain forest cover in the Amazon region. At the same time, it shows how studies like this one can help in decision-making.

Modelling Global Deforestation Using Spherical Geographic Automata Approach

Deforestation as a land-cover change process is linked to several environmental problems including desertification, biodiversity loss, and ultimately climate change. Understanding the land-cover change process and its relation to human–environment interactions is important for supporting spatial decisions and policy making at the global level. However, current geosimulation model applications mainly focus on characterizing urbanization and agriculture expansion. Existing modelling approaches are also unsuitable for simulating land-cover change processes covering large spatial extents. Thus, the objective of this research is to develop and implement a spherical geographic automata model to simulate deforestation at the global level under different scenarios designed to represent diverse future conditions. Simulation results from the deforestation model indicate the global forest size would decrease by 10.5% under the “business-as-usual” scenario through 2100. The global forest extent would also decline by 15.3% under the accelerated deforestation scenario and 3.7% under the sustainable deforestation scenario by the end of the 21st century. The obtained simulation outputs also revealed the rate of deforestation in protected areas to be considerably lower than the overall forest-cover change rate under all scenarios. The proposed model can be utilized by stakeholders to examine forest conservation programs and support sustainable policy making and implementation.

Assessing the impacts of past and ongoing deforestation on rainfall patterns in South America.

Despite recent advances in modeling forest-rainfall relationships, the current understanding of changes in observed rainfall patterns resulting from historical deforestation remains limited. To address this knowledge gap, we analyzed how 40 years of deforestation has altered rainfall patterns in South America as well as how current Amazonian forest cover sustains rainfall. First, we develop a spatiotemporal neural network model to simulate rainfall as a function of vegetation and climate inputs in South America; second, we assess the rainfall effects of observed deforestation in South America during the periods 1982-2020 and 2000-2020; third, we assess the potential rainfall changes in the Amazon biome under two deforestation scenarios. We find that, on average, cumulative deforestation in South America from 1982 to 2020 has reduced rainfall over the period 2016-2020 by 18% over deforested areas, and by 9% over non-deforested areas across South America. We also find that more recent deforestation, that is, from 2000 to 2020, has reduced rainfall over the period 2016-2020 by 10% over deforested areas and by 5% over non-deforested areas. Deforestation between 1982 and 2020 has led to a doubling in the area experiencing a minimum dry season of 4 months in the Amazon biome. Similarly, in the Cerrado region, there has been a corresponding doubling in the area with a minimum dry season of 7 months. These changes are compared to a hypothetical scenario where no deforestation occurred. Complete conversion of all Amazon forest land outside protected areas would reduce average annual rainfall in the Amazon by 36% and complete deforestation of all forest cover including protected areas would reduce average annual rainfall in the Amazon by 68%. Our findings emphasize the urgent need for effective conservation measures to safeguard both forest ecosystems and sustainable agricultural practices.

The effects of climate and forest cover variability on the hydrological regulation of an eastern Andean Cusiana river sub-basin

The hydrologic regulation analysis on a basin scale requires the understanding of the spatio-temporal heterogeneity of the climate regime and the land cover. The Cusiana river sub-basin (4992 km2) is part of the Colombian Orinoco River basin and its important because of the ecosystem services it provides. However, there is limited knowledge about the factors that govern its hydrological functioning. In this study we aimed at describing the relation between the forest cover and the hydroclimatic tendencies with the hydrologic regulation of this basin. For this, we evaluated rainfall and evapotranspiration spatial variability and the temporal tendencies of these variables and streamflow employing the Mann-Kendall test for a dataset covering from 1980 till 2020. Streamflow data was obtained from various gauging sites at different points along the main streambed between 290 and 3135 m a.s.l. We also evaluated the basin's forest cover changes between 2003 and 2019 using official land cover classification maps. With the hydroclimatic and land cover analyzes we created potential scenarios of extreme dry and wet years and of deforestation and restoration. These extreme scenarios were forced in the previously calibrated and validated Seasonal Water Yield module of the InVEST model to evaluate their effects on base and quickflows. Results show that there are no homogeneous tendencies in the rainfall, evapotranspiration, or streamflow within this basin. Furthermore, streamflow tends to decrease in the basin segments that show an increase in forest cover. The model outputs suggest that the magnitude of the baseflow decrease under a deforestation scenario is up to 3.6 times larger than the increase in baseflow under a forest cover restoration scenario, and that the quickflows can increase up to 1.4 times more in a combined wet year and deforestation scenario, than in an average year under current forest cover. From our results we identify that the spatial relation between land cover, climate and hydrologic regulation must be explicitly evaluated for the design of water resources management plans for any Andean River basin.

Employing oxford nanopore technologies (ONT) for understanding the ecology and transmission dynamics of flaviviruses in mosquitoes (Diptera: Culicidae) from Eastern Colombia

Studies focused on identifying the viral species of Flavivirus in vectors are scarce in Latin America and particularly in Colombia. Therefore, the frequency of infection of the Flavivirus genus and its feeding preferences were identified in the mosquito species circulating in the municipality of Puerto Carreño-Vichada, located in the Eastern Plains of Colombia. This was done by sequencing the viral NS5 and vertebrate 12S rRNA genes, respectively, using Oxford Nanopore Technologies (ONT). A total of 1,159 mosquitoes were captured, with the most abundant species being Aedes serratus at 73.6% (n = 853). All the mosquitoes were processed in 230 pools (2–6 individuals) and 51 individuals, where 37.01% (n = 104) were found to be infected with Flavivirus. In these samples, infection by arboviruses of epidemiological importance, such as dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV), was ruled out by PCR. However, through sequencing, infection by different insect-specific viruses (ISFVs) and a medically important virus, West Nile virus (WNV), were identified in a mosquito of the Culex browni species. Additionally, the feeding patterns showed that most species present a generalist behavior. Given the above, conducting entomovirological surveillance studies is crucial, especially in areas of low anthropogenic intervention, due to the high probability that potentially pathogenic viruses could generate spillover events under deforestation scenarios.

Agroforestry Systems on Brazilian Legal Protected Lands: Permanent Preservation Areas (PPA) and Legal Reservation Areas (LRA)

Forests preservation and restoration are crucial, to sustain ecological and social benefits. Agroforestry systems are important land use restoration instruments because they allow food production combined with sustainable forest management. There are different kinds of agroforestry systems, and they can occur in degradedareas andin forested areas which are legally protected or not. In Brazil, where forests cover 46.5% of land area, deforestation continues and there are several challenges to protect and restore forests. Permanent Preservation Areas (PPA) and Legal Reservation Areas (LRA), which have been institutionalized in Brazilian Environmental Legislation require the maintenance of areas with native vegetation within rural properties restricting certain activities. Historically, they have not been duly respected by most land owners where riverbanks, springs, slopes and other areas have been occupied suppressing natural vegetation. Thus, there are possibilities for ecological management and use of PPA and mainly LRA, which seek to both preserve environmental resources and contribute to food production and income, especially in the campesino smallholders. This paper discusses possibilities and limitations of using agroforestry systems in PPA and LRA, pointing out that agroforestry systems are also feasible for restoring degraded areas and for expanding enriched areas and uses of their natural resources. Despite legal possibilities, a historical problem in Brazil is related to the lack of compliance with environmental legislation. Moreover, the scenario of deforestation and several difficulties to advance in environmental management in Brazil have been harming this conservationist possibilities.

A possible deforestation-induced synoptic-scale circulation that delays the rainy season onset in Amazonia

The physical hydroclimate system of the Amazon functions on several spatial and temporal scales. Large-scale processes control the main seasonal patterns of atmospheric circulation and rainfall. Seasonal variability in solar forcing, associated with the low rainforest albedo, provides energy for continental heating, convection, and the onset of the South American monsoon. Mesoscale processes cause localized circulations such as river breeze and deforestation breeze. We assessed the impact of different deforestation scenarios for the mid-century last decade rainy season. Here we describe a yet unreported synoptic-scale circulation that delays the rainy season onset in southern Amazonia. This model-predicted circulation is driven by extensive (ca. 40%) deforestation patterns and may last as long as two months. This persistent anomalous circulation may result in a rainy season onset delay of 30–40 d compared to the historical period. Like other synoptic-scale phenomena, differences in surface heating drive this circulation. Given the unabated deforestation trends, the consequences for local ecosystems, agriculture, and power generation of delayed rainy season onset associated with this circulation may be difficult to revert.

Functional Potential of Soil Microbial Communities and Their Subcommunities Varies with Tree Mycorrhizal Type and Tree Diversity.

Soil microbial communities play crucial roles in the earth's biogeochemical cycles. Yet, their genomic potential for nutrient cycling in association with tree mycorrhizal type and tree-tree interactions remained unclear, especially in diverse tree communities. Here, we studied the genomic potential of soil fungi and bacteria with arbuscular (AM) and ectomycorrhizal (EcM) conspecific tree species pairs (TSPs) at three tree diversity levels in a subtropical tree diversity experiment (BEF-China). The soil fungi and bacteria of the TSPs' interaction zone were characterized by amplicon sequencing, and their subcommunities were determined using a microbial interkingdom co-occurrence network approach. Their potential genomic functions were predicted with regard to the three major nutrients carbon (C), nitrogen (N), and phosphorus (P) and their combinations. We found the microbial subcommunities that were significantly responding to different soil characteristics. The tree mycorrhizal type significantly influenced the functional composition of these co-occurring subcommunities in monospecific stands and two-tree-species mixtures but not in mixtures with more than three tree species (here multi-tree-species mixtures). Differentiation of subcommunities was driven by differentially abundant taxa producing different sets of nutrient cycling enzymes across the tree diversity levels, predominantly enzymes of the P (n = 11 and 16) cycles, followed by the N (n = 9) and C (n = 9) cycles, in monospecific stands and two-tree-species mixtures, respectively. Fungi of the Agaricomycetes, Sordariomycetes, Eurotiomycetes, and Leotiomycetes and bacteria of the Verrucomicrobia, Acidobacteria, Alphaproteobacteria, and Actinobacteria were the major differential contributors (48% to 62%) to the nutrient cycling functional abundances of soil microbial communities across tree diversity levels. Our study demonstrated the versatility and significance of microbial subcommunities in different soil nutrient cycling processes of forest ecosystems. IMPORTANCE Loss of multifunctional microbial communities can negatively affect ecosystem services, especially forest soil nutrient cycling. Therefore, exploration of the genomic potential of soil microbial communities, particularly their constituting subcommunities and taxa for nutrient cycling, is vital to get an in-depth mechanistic understanding for better management of forest soil ecosystems. This study revealed soil microbes with rich nutrient cycling potential, organized in subcommunities that are functionally resilient and abundant. Such microbial communities mainly found in multi-tree-species mixtures associated with different mycorrhizal partners can foster soil microbiome stability. A stable and functionally rich soil microbiome is involved in the cycling of nutrients, such as carbon, nitrogen, and phosphorus, and their combinations could have positive effects on ecosystem functioning, including increased forest productivity. The new findings could be highly relevant for afforestation and reforestation regimes, notably in the face of growing deforestation and global warming scenarios.

Effects on early monsoon rainfall in West Africa due to recent deforestation in a convection-permitting ensemble

Abstract. Tropical deforestation can have a significant effect on climate, but research attention has been directed mostly towards Amazonian deforestation. The southern part of West Africa (a region dependent on rain-fed agriculture and vulnerable to droughts and flooding) has seen significant deforestation since the 1950s. Many previous tropical deforestation studies have used idealized and exaggerated deforestation scenarios and parameterized convection models. In this study we estimate for the first time realistic historical deforestation from the Land-Use Harmonization dataset in West Africa and simulate the impacts in a 5 d ensemble forecast in June using a convection-permitting regional climate model. We find that sensible heat flux increases at the expense of latent heat flux in most deforested regions, and rainfall increases by an average of 8.4 % over deforested pixels from 18:00–06:00 UTC, whereas changes are much less pronounced during the day. Over large areas of deforestation approx. 300 km inland (e.g. west Guinea) the roughness-length and thermally enhanced convergence during the afternoon and evening occurs over the deforested areas resulting in increases in rainfall with little impact from reduced daytime humidity. In areas of coastal deforestation (e.g. Côte d'Ivoire), increased winds drive the sea breeze convection inland, resulting in evening rainfall reductions over the deforested area but increases further inland, in line with observations. We suggest our results would not be replicated in parameterized convection models, which are known to struggle with capturing peak convective activity in the late afternoon and long-lived nocturnal rainfall and with reproducing observed surface–rainfall feedbacks.