Navegando por Assunto "Climate change"

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Acesso aberto (Open Access)
Conservação do Jaborandi (Pilocarpus microphyllusStapf Ex Wardleworth) no Norte do Brasil: diversidade genética e impactos das mudanças climáticas futuras
(Universidade Federal do Pará, 2023-05-31) CORRÊA, Waléria Pereira Monteiro; CALDEIRA JUNIOR, Cecílio Frois; http://lattes.cnpq.br/4071467514868919; https://orcid.org/0000-0003-4762-3515; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685; https://orcid.org/0000-0001-6045-0984
Jaborandi (Pilocarpus microphyllus Stapf Ex Wardleworth) is a medicinal plant found in the north/northeast of Brazil. In recent decades, disordered extractive exploitation, the advance of agriculture and other activities that result in deforestation, as well as ongoing climate changes, have induced direct and indirect impacts on the survival of this plant species. Jaborandi is a natural source of pilocarpine, an alkaloid used in the pharmaceutical industry to treat glaucoma and xerostomia. Therefore, the species is socio-environmental interest because the extractivism of its leaves has generated financial income for countless families, in addition to contributing to the conservation of the species in the region. In order to contribute to long-term conservation and survival strategies for the species, this study evaluated the structure and genetic diversity of the species P. microphyllus in a Conservation Unit (UC) in southeastern Pará (FLONA Carajás), as well as an environmental modeling study was developed to analyze the impacts of climate change on the geographic distribution of occurrence of jaborandi, in order to delineate suitable areas according to future climate scenarios. The results of the genetic study demonstrated the formation of 04 populations with high diversity and ecological structure, even with continuous extractivism within the Carajás FLONA, indicating that exploration has been taking place in a sustainable manner in the region. In the modeling study, the projections indicated impacts of climate change on the distribution of P. microphyllus with a reduction in suitable areas in the Cerrado and Caatinga biomes (Maranhão and Piauí) and expansion of the species in the protected areas of forest cover of the Amazon biome in southeastern Pará. The results of this study contribute to the understanding of diversity in the FLONA of Carajás and reinforce the need for management and conservation plans for P. microphyllus in priority areas, where the species finds favorable climatic conditions in future scenarios. In situ and ex situ conservation measures for this species are essential, since extracting the leaves contributes as a source of income for local communities.
Acesso aberto (Open Access)
Estimativas de curvas IDF e curvas de permanência na Amazônia sob a influência de mudanças climáticas
(Universidade Federal do Pará, 2021-02-05) COSTA, Carlos Eduardo Aguiar de Souza; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
The impacts on global water resources may be more intense due to climate change, making access to water more difficult and, consequently, maintaining life. In the Amazon, the effect may be even worse, as it is one of the regions most vulnerable to these changes. Representative Concentration Pathways (RCPs) scenarios are essential tools for General Circulation Models (GCMs) and Global Hydrological Models (GHMs) to simulate future climate change. Intensity, Duration and Frequency (IDF) curves and flow duration curves are fundamental for the elaboration of hydraulic projects and risk management. Thus, the objective of this study was to elaborate projections of IDF curves for the Tapajós watershed in RCP 4.5 and 8.5, using data from GCMs HadGEM2-ES, CanESM2 and MIROC5. Another objective was to analyze variations in the permanence curves and available volumes of the Amazon River using data from the GHM WaterGAP2 forced by MIROC5 and HadGEM2-ES (in RCPs 6.0 and 8.5). The projected IDF curves were compared with the existing IDF, elaborated using a stationary method. The base permanence curves were created from the last 20 years of observed flows and compared with the curves of future scenarios (from 2020). They were calculated from decadal volumes. The biggest differences for the projected IDF curves were in MIROC5 (143.15% in RCP 8.5) and the smallest differences were in HadGEM2-ES (4% in RCP 4.5) both for the 100-year return period. The spatial resolutions of each GCM influenced their IDF curves, since CanESM2 did not present satisfactory results and MIROC5 was the one that best represented the possible future differences. WaterGAP2 presented the classification “Very Good” for most stations according to statistical validation indicators. Most of the extreme flows were for 2080 to 2099. For WaterGAP2 (MIROC5), most volumes were below the century's decadal average, increasing from 2060. For WaterGAP2 (HadGEM2-ES) projections the volumes are usually close or below the decadal average, falling from 2060 onwards. MIROC5 is the most suitable for studies of climate projections in the Amazon.
Acesso aberto (Open Access)
A evolução dos manguezais nos litorais Nordeste e Sul brasileiros durante o Holoceno
(Universidade Federal do Pará, 2020-09-30) FREIRE, Neuza Araújo Fontes; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
It is possible that climate changes and sea level fluctuations (allogenic processes) are and will cause major changes in mangrove dynamics. However, other driving forces may be significantly affecting this system. Distinguishing allogenic and autogenic influence on mangroves is a challenging question, because mechanisms related to the natural dynamics of depositional environments (autogenic processes) have strong influences on the establishment and degradation of mangroves. Thus, impacts on mangroves caused by autogenic processes may be erroneously attributed to allogenic mechanisms. Therefore, it is imperative to identify the ‘fingerprint’ of global changes in modern mangrove dynamics. This thesis integrates palynological, geochemical, sedimentological data, 14C dating of sedimentary organic matter, geomorphological and vegetation data in order to evaluate the influence of autogenic and allogeneic processes on Brazilian mangroves during the Holocene. Tropical estuaries from Rio Grande do Norte and southern Bahia, and subtropical estuaries in northern and southern Santa Catarina estates with different climatic, geomorphological and oceanographic characteristics were studied. The Relative Sea-Level (RSL) along the Rio Grande do Norte reached modern level and stabilized at about 7,000 cal yr BP, allowing the mangrove establishment at the edges of the Ceará-Mirim River estuary until the nowadays. However, changes in the spatial distribution of mangroves have occurred since then due to channels dynamics in the region (autogenic processes). Considering the mangroves of the Jucuruçu River in southern Bahia, their horizontal and vertical distribution were controlled by the interactions of the changes in the RSL and fluvial discharge. Therefore, the dynamics of these estuarine mangroves during the Holocene was mainly controlled by changes in sea level and precipitation that affected fluvial discharge. These allogeneic mechanisms were the main drivers of the dynamics of these mangroves. However, during the last 600 years, factors intrinsic to the depositional system gained relevance by controlling the establishment and migration of mangroves by deposition and erosion of muddy tidal flats, abandonment and reactivation of channels (autogenic processes). In the case of Santa Catarina mangroves, the RSL rise up to the middle Holocene was decisive for the establishment of tidal flats appropriate for the expansion of saltmarshes. However, mangroves did not tolerate the Holocene low temperatures in the southern littoral of Santa Catarina. The pollen data indicate the establishment of mangroves with Laguncularia around 1,700 cal yr BP, followed by Avicennia and lastly Rhizophora trees, a cold less tolerant genus, around 650 cal yr BP in São Francisco do Sul, north of Santa Catarina. The mangroves of Laguna, south of Santa Catarina, composed of Laguncularia and Avicennia, were established in the current southern limit of the South American mangroves only in the last decades. No evidence was found for the presence of mangroves in Laguna during the Holocene. The establishment of these mangroves in the region probably started during the Anthropocene, as a consequence of the increase in minimum winter temperatures in southern Brazil. Considering changes in precipitation rates over drainage basins that feed mangrove estuaries, as well as trends in RSL rise and temperatures until the end of the 21st century, tropical estuarine mangroves will likely migrate to higher topographically sectors in the interior of the river valleys, where its extension will depend on the volume of river discharge interacting with the RSL rise. Subtropical mangroves are expected to expand to more temperate zones as minimum winter temperatures increase. This process should cause an increase in the diversity of mangrove species, such as the introduction of the Rhizophora genus in the current southern limit of the mangroves, positioned in Laguna-SC. However, in the case of high rates of RSL rise, the relatively new subtropical mangroves are also expected to migrate to topographically higher sectors of the coast.
Acesso aberto (Open Access)
A expansão dos manguezais na foz do rio Itapicuru (Ba) durante o Antropoceno
(Universidade Federal do Pará, 2022-09-20) SANTOS, Larissa Roberta Oliveira Castro; FRANÇA, Marlon Carlos; http://lattes.cnpq.br/8225311897488790; https://orcid.org/0000-0002-3784-7702
The objective of this work was to evaluate mangrove dynamics during the Anthropocene, as well as the influence of climate change on mangroves and associated vegetation units at the mouth of the Tapicuru River in northern Bahia State, northeastern Brazil. The development of this work was carried out by integrating sedimentological, palynological, isotopic and Pb-210 dating data in a sedimentary core. The isotopic results for δ13C revealed a relatively stable pattern with depleted isotopic values (-27‰ to -23.3‰), typical of organic matter originating from C3 vegetation input. Palynology indicated the presence of five ecological groups: mangroves, herbs, trees and shrubs, palms and spores. Pollen results from T1 core show two zones (zone 1: 85-34 cm depth and zone 2: 34-0 cm depth), according to cluster analysis. Zone 1 is marked by a trend of decreasing mangrove vegetation, while zone 2 shows a trend of increasing mangrove vegetation characterized mostly by the presence of Rhizophora.
Acesso aberto (Open Access)
Exposição das florestas da Amazônia à velocidade das mudanças climáticas
(Universidade Federal do Pará, 2021-02-19) AMARAL, Calil Torres; VIEIRA, Ima Célia Guimarães; http://lattes.cnpq.br/3761418169454490; https://orcid.org/0000-0003-1233-318X; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685; https://orcid.org/0000-0001-6045-0984
Climate change is occurring at an accelerated rate and, as a result, species must produce adaptive responses to survive. The redistribution of biodiversity is one of the most anticipated effects for tropical species, as they have narrow thermal niches that make them less able to adapt to new environmental conditions. Evidence has already been observed in many Amazonian taxonomic groups, however, it remains uncertain whether the species will be able to follow up future climate changes. The amazon is among the global regions most exposed to long distances to climates analogs and to the emergence of new climate conditions. Along with this, the advance of deforestation may restrict the amount of habitats favorable to the distribution of species in the future, in addition to impairing connectivity to areas with a similar climate. Protected areas (PAs) can contribute to the redistribution of Amazonian biodiversity as climate havens, representing an important connectivity strategy between present and future climates, but they may be insufficient, given the speed of climate change promoted by human activities. Climate velocities represent a method to quantify the rate at which species must change their distribution in order to preserve their current climatic adaptation characteristics. In this work, the speed of climate change in the Amazon biome is investigated, based on climatic analogues between the present and the future, from the directions of advancement (present-future) and retreat (future-present), emphasizing the network of PAs in the region. The median climatic velocity of these areas was compared with that of unprotected areas (UAs), in order to verify the effectiveness of PAs in maintaining favorable climatic conditions for the adaptation of species in future climate change scenarios. In addition, the climatic refuges of the Amazon biome were identified and the impact of deforestation on these areas was quantified. To achieve these objectives, data from annual air temperature and precipitation averages with a spatial resolution of 10 km were used, in order to describe the current (1970-2000) and future (2041-2060) mesoclimates. The results show that the effects of the recoil speed will be greater in magnitude and spatial extension. Despite this, the network of PAs will be less exposed to the impacts of the recoil speed than UAs - emphasizing the importance of these areas as a tool in conservation. In contrast, for impacts related to the speed of advancement, the PA network will be slightly more exposed than PAs - indicating that the current spatial layout of the PA network is still not the most suitable for minimizing the impacts of climate change. It was also found that climatic refuges occupy only 7% of the Amazon biome, and are distributed along the edges of the biogeographic limit. In just 12 years, deforestation has caused a loss of more than 5% of these areas. In view of this scenario, it is necessary to further limit the loss of forests and include climate refuges in the conservation agendas of the Amazon, in order to enhance the conservation of the biota of Amazonian forests under climate change scenarios.
Acesso aberto (Open Access)
Exposição das florestas da Amazônia à velocidade das mudanças climáticas
(Universidade Federal do Pará, 2021-03-19) AMARAL, Calil Torres; VIEIRA, Ima Célia Guimarães; http://lattes.cnpq.br/3761418169454490; https://orcid.org/0000-0003-1233-318X; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685; https://orcid.org/0000-0001-6045-0984
Climate change is occurring at an accelerated rate and, as a result, species must produce adaptive responses to survive. The redistribution of biodiversity is one of the most anticipated effects for tropical species, as they have narrow thermal niches that make them less able to adapt to new environmental conditions. Evidence has already been observed in many Amazonian taxonomic groups, however, it remains uncertain whether the species will be able to follow up future climate changes. The amazon is among the global regions most exposed to long distances to climates analogs and to the emergence of new climate conditions. Along with this, the advance of deforestation may restrict the amount of habitats favorable to the distribution of species in the future, in addition to impairing connectivity to areas with a similar climate. Protected areas (PAs) can contribute to the redistribution of Amazonian biodiversity as climate havens, representing an important connectivity strategy between present and future climates, but they may be insufficient, given the speed of climate change promoted by human activities. Climate velocities represent a method to quantify the rate at which species must change their distribution in order to preserve their current climatic adaptation characteristics. In this work, the speed of climate change in the Amazon biome is investigated, based on climatic analogues between the present and the future, from the directions of advancement (present-future) and retreat (future-present), emphasizing the network of PAs in the region. The median climatic velocity of these areas was compared with that of unprotected areas (UAs), in order to verify the effectiveness of PAs in maintaining favorable climatic conditions for the adaptation of species in future climate change scenarios. In addition, the climatic refuges of the Amazon biome were identified and the impact of deforestation on these areas was quantified. To achieve these objectives, data from annual air temperature and precipitation averages with a spatial resolution of 10 km were used, in order to describe the current (1970-2000) and future (2041-2060) mesoclimates. The results show that the effects of the recoil speed will be greater in magnitude and spatial extension. Despite this, the network of PAs will be less exposed to the impacts of the recoil speed than UAs - emphasizing the importance of these areas as a tool in conservation. In contrast, for impacts related to the speed of advancement, the PA network will be slightly more exposed than PAs - indicating that the current spatial layout of the PA network is still not the most suitable for minimizing the impacts of climate change. It was also found that climatic refuges occupy only 7% of the Amazon biome, and are distributed along the edges of the biogeographic limit. In just 12 years, deforestation has caused a loss of more than 5% of these areas. In view of this scenario, it is necessary to further limit the loss of forests and include climate refuges in the conservation agendas of the Amazon, in order to enhance the conservation of the biota of Amazonian forests under climate change scenarios.
Acesso aberto (Open Access)
Impactos das mudanças climáticas na biomassa florestal Amazônica: Previsão de perda e estratégias de conservação prioritárias para o potencial de biomassa sob as mudanças climáticas
(Universidade Federal do Pará, 2024-04-25) CAMPOS, Mayara Soares; ANJOS, Luciano Jorge Serejo dos; http://lattes.cnpq.br/0244738999001686; https://orcid.org/0000-0002-3270-6679; ADAMI, Marcos; http://lattes.cnpq.br/7484071887086439; https://orcid.org/0000-0003-4247-4477
The study addresses the influence of climate change on Aboveground Biomass (AGB) in the Amazon, examining both reduction forecasts and potential increases under different climate scenarios until the end of the century. Using AGB data (GEDI) and climate variables from Global Circulation Models (GCM‘s) and Shared Socioeconomic Pathways (SSP‘s), the research employs Geographically Weighted Regression (GWR) to explore spatial patterns of AGB distribution. The results point to a significant decline in AGB, with estimated reductions ranging from 14.2% to 32.1%, where the average vegetation density could drop to 177.61 Mg/ha-1 by 2040 and 140.43 Mg/ha-1 by 2100, indicating a decrease in the forest's carbon sequestration capacity, especially in the northeast, central-east, west, and south regions of the Amazon. Conversely, potential AGB gains were identified in specific areas of the Brazilian Amazon, mainly in the northwest and southeast regions, covering the Negro, Xingu, and Tapajós river basins, under both future scenarios. Indigenous Lands (TI‘s) emerge as crucial for conservation, exhibiting greater AGB gains in both scenarios analyzed. This study underscores the importance of mitigation strategies and the role of protected areas in maintaining Amazon resilience in the face of future climate adversities. By highlighting areas of potential AGB increase, it emphasizes the significance of preserving and valuing protected areas and TI‘s as fundamental strategies to address environmental and climate challenges. This approach not only focuses on mitigating AGB loss but also recognizes the potential of specific regions to positively contribute to Amazon resilience amid future climate changes. Therefore, this study is of great importance for both science and public policy formulations, as it provides an analysis of the impact of AGB climate change in the Amazon, essential in the carbon cycle and, by extension, in mitigating global climate change. By identifying vulnerable regions and those with potential AGB increase, it highlights the urgency of targeted conservation strategies.
Acesso aberto (Open Access)
Impactos do avanço da soja no balanço de radiação no leste da Amazônia
(Instituto Nacional de Pesquisas da Amazônia, 2013-06) SOUZA, Paulo Jorge de Oliveira Ponte de; ROCHA, Edson José Paulino da; RIBEIRO, Aristides
The deforestation of the Amazon, especially for pasture use, has been explored by several researchers who have pointed out as a consequence, serious environmental problems. The continuous expansion of agriculture on areas of cattle ranching in the Amazon, as well as on native areas, must be seen with caution since few studies have been conducted in order to investigate which probable environmental impacts can be generated due to the presence of soybean monoculture in the region. This study evaluates the local impacts of the replacement of forest by soybean (Glycine max (L.) Merrill) on radiation balance components in an area that represents the agricultural border advancement in Amazonia. A micrometeorological experiment was installed in an area of soybean cultivation in Paragominas-PA and data from forest ecosystems were collected in Caxiuanã forests located in Melgaço-PA both during 2006 and 2007. During the soybean growing season the mean impact found in net radiation represented a reduction of 17.9% of the value commonly observed in the forest. During the off-season the impact on net radiation was 15.5%. Principal mechanisms that control these impacts were associated with the high soybean albedo and high loss of long wave radiation. Although the greatest impact occurs during the crop growing season, the time of occurrence of this negative effect is restricted to only 1/3 of the year, which leads to a higher impact of the off-season on energy balance in cumulative terms.
Acesso aberto (Open Access)
Percepção dos gestores de reservas extrativistas marinhas sobre os efeitos das mudanças climáticas no salgado paraense - Pará-Brasil
(Universidade Federal do Pará, 2021-08-24) BECERRA RUIZ, Melgris José; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685; https://orcid.org/0000-0001-6045-0984; PIMENTEL, Márcia Aparecida da Silva; http://lattes.cnpq.br/3994635795557609; https://orcid.org/0000-0001-9893-9777
Climate change is an issue that, since the last century has gained interest among scientists around the world, there are many information that have been turned to address this issue from different fronts, however, the perception of local communities is far away to be one of the most successful work topics. Brazil has a network of Extractive Reserves (RESEX), which is part of protected natural areas and where environmental managers participate who exercise control, monitoring, implementation of projects that serve as a basis for the conservation of RESEX, as well as a contact direct with local communities. Many mangrove ecosystems are concentrated in the RESEX of the Paraense coast. Around these ecosystems, traditional communities have settled that make use, enjoyment, and enjoyment of them, which have incorporated into their daily activities offered by the mangroves, which ranges from leisure, pleasure, and enjoyment to the generation of income to maintain the lifetime. In this sense, in this work the coastal region of the north of Pará was approached, the so-called Salgado Paraense with the aim of knowing the perception of local actors and the effects of climate change in this territory. To achieve this objective, the work was carried out in two phases. A first study was carried out to find out the amount of published bibliography on the perception of climate change around the world, in three main languages such as Spanish, English and Portuguese. For this bibliographic analysis, we applied natural language and machine learning to analyze more than 30,000 scientific articles. Some maps were produced on study trends, countries with major researchers interested in this topic, the methodologies used, and the approaches taken to understand the effects of climate change. Subsequently, in the second phase, surveys were applied to the environmental managers of the RESEX studied, to know their perception of climate change, interest in the adoption of adaptation strategies in the face of climate change and their perception of the role of the women in social dynamics within RESEX in the face of climate change threats. The findings suggest that studies on the perception of climate change in the coastal communities of northern Pará are necessary and have a lot of potential for their research, since the interested actors really have an affinity in adopting measures against the impacts of climate change, they show their concern about the effects on communities and mangroves, generating an alert and a call to incorporate local populations with more interest in the design and implementation of adequate and pertinent public policies. It is necessary that the actors of organized civil society, community, managers, and governments at different scales understand that the challenges are increasing to face climate change, this situation is worrying in various parts of the world, it is therefore, necessary to incorporate the vision of local communities.
Acesso aberto (Open Access)
Produtividade de citrus na Amazônia Oriental: relações com o clima atual, risco socioambiental relativo aos eventos extremos e modelagem dos impactos das mudanças climáticas futuras
(Universidade Federal do Pará, 2023-05-31) DIAS, Thaiane Soeiro da Silva; RUIVO, Maria de Lourdes Pinheiro; http://lattes.cnpq.br/9419564604488031; HTTPS://ORCID.ORG/0000-0002-6222-5534; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685; https://orcid.org/0000-0001-6045-0984
In the context of the agricultural frontier within the Amazonian territory, the production of citrus (lime and oranges) has been relevant in socioeconomic and environmental terms. In this thesis, three different scientific approaches were developed to elucidate: i) the relationships between citrus productivity and climate variability (rainfall and air temperature) and deforestation patterns in eastern Amazonia during the last decades; ii) the socio-environmental risk of citrus productivity due to extreme precipitation events in eastern Amazon; and iii) the impacts of different future scenarios of climate change on the distribution of potential areas of occurrence of the species Citrus sinensis over the Legal Brazilian Amazon. The results showed evidence that natural factors (climate variability and extreme precipitation events) and anthropic factors (deforestation) directly influence citrus productivity in several areas of eastern Amazonia. In addition, projections indicate that climate change can negatively impact the distribution of the main occurrence areas of the Citrus species throughout the Brazilian Legal Amazon.