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1.
Nat Commun ; 12(1): 1785, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741981

RESUMEN

Tropical secondary forests sequester carbon up to 20 times faster than old-growth forests. This rate does not capture spatial regrowth patterns due to environmental and disturbance drivers. Here we quantify the influence of such drivers on the rate and spatial patterns of regrowth in the Brazilian Amazon using satellite data. Carbon sequestration rates of young secondary forests (<20 years) in the west are ~60% higher (3.0 ± 1.0 Mg C ha-1 yr-1) compared to those in the east (1.3 ± 0.3 Mg C ha-1 yr-1). Disturbances reduce regrowth rates by 8-55%. The 2017 secondary forest carbon stock, of 294 Tg C, could be 8% higher by avoiding fires and repeated deforestation. Maintaining the 2017 secondary forest area has the potential to accumulate ~19.0 Tg C yr-1 until 2030, contributing ~5.5% to Brazil's 2030 net emissions reduction target. Implementing legal mechanisms to protect and expand secondary forests whilst supporting old-growth conservation is, therefore, key to realising their potential as a nature-based climate solution.


Asunto(s)
Secuestro de Carbono , Carbono/metabolismo , Cambio Climático , Bosques , Clima Tropical , Algoritmos , Biomasa , Brasil , Conservación de los Recursos Naturales/métodos , Ecosistema , Fuego , Agricultura Forestal , Geografía , Modelos Teóricos , Imágenes Satelitales/métodos , Árboles/crecimiento & desarrollo , Árboles/metabolismo
3.
Nat Commun ; 12(1): 1023, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33589628

RESUMEN

Australia's 2019-2020 'Black Summer' bushfires burnt more than 8 million hectares of vegetation across the south-east of the continent, an event unprecedented in the last 200 years. Here we report the impacts of these fires on vascular plant species and communities. Using a map of the fires generated from remotely sensed hotspot data we show that, across 11 Australian bioregions, 17 major native vegetation groups were severely burnt, and up to 67-83% of globally significant rainforests and eucalypt forests and woodlands. Based on geocoded species occurrence data we estimate that >50% of known populations or ranges of 816 native vascular plant species were burnt during the fires, including more than 100 species with geographic ranges more than 500 km across. Habitat and fire response data show that most affected species are resilient to fire. However, the massive biogeographic, demographic and taxonomic breadth of impacts of the 2019-2020 fires may leave some ecosystems, particularly relictual Gondwanan rainforests, susceptible to regeneration failure and landscape-scale decline.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Bosque Lluvioso , Incendios Forestales/estadística & datos numéricos , Australia , Bosques , Humanos , Estaciones del Año
4.
Nat Commun ; 12(1): 519, 2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33483481

RESUMEN

The complexity of forest structures plays a crucial role in regulating forest ecosystem functions and strongly influences biodiversity. Yet, knowledge of the global patterns and determinants of forest structural complexity remains scarce. Using a stand structural complexity index based on terrestrial laser scanning, we quantify the structural complexity of boreal, temperate, subtropical and tropical primary forests. We find that the global variation of forest structural complexity is largely explained by annual precipitation and precipitation seasonality (R² = 0.89). Using the structural complexity of primary forests as benchmark, we model the potential structural complexity across biomes and present a global map of the potential structural complexity of the earth´s forest ecoregions. Our analyses reveal distinct latitudinal patterns of forest structure and show that hotspots of high structural complexity coincide with hotspots of plant diversity. Considering the mechanistic underpinnings of forest structural complexity, our results suggest spatially contrasting changes of forest structure with climate change within and across biomes.


Asunto(s)
Cambio Climático , Clima , Ecosistema , Bosques , Árboles/crecimiento & desarrollo , Conservación de los Recursos Naturales/métodos , Agricultura Forestal/métodos , Geografía , Modelos Teóricos , Lluvia , Estaciones del Año , Árboles/clasificación
5.
Artículo en Inglés | MEDLINE | ID: mdl-33477844

RESUMEN

The public perception of renewable energy sources is generally positive, due to their role in air pollution and CO2 emission mitigation policies. However, there are local environmental detrimental effects, and empirical evidence is not consistent as to the support of local communities. In the present paper, we analyse the antecedents of public generic perceptions of renewables grounded on objective location-related factors. Personal location-related factors can originate in the involvement of individuals with renewable energy sources. Regional location-related factors concern the importance of the renewable energy source in the district of residence and in relation to other renewables. We implement a questionnaire on public perceptions of renewable energy sources by the general population in mainland Portugal and complement respondent-level responses with renewable energy district information. Regression analysis shows that these objective location-related factors, both personal and regional, help explain public perceptions of renewables and thus we find empirical support for the proposed approach. These results can inform and guide policymakers in tackling future social acceptance issues of renewable energy policies towards lower carbon emissions and less polluting energy production.


Asunto(s)
Contaminación del Aire/prevención & control , Conservación de los Recursos Naturales/métodos , Fuentes Generadoras de Energía , Contaminación Ambiental/análisis , Energía Renovable , Dióxido de Carbono/análisis , Humanos , Portugal
6.
PLoS One ; 16(1): e0238087, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33395430

RESUMEN

The Tapanuli Orangutan (Pongo tapanuliensis) is the most threatened great ape species in the world. It is restricted to an area of about 1,000 km2 of upland forest where fewer than 800 animals survive in three declining subpopulations. Through a historical ecology approach involving analysis of newspaper, journals, books and museum records from the early 1800s to 2009, we demonstrate that historically Pongo tapanuliensis inhabited a much larger area, and occurred across a much wider range of habitat types and at lower elevations than now. Its current Extent of Occurrence is 2.5% and 5.0% of the historical range in the 1890s and 1940s respectively. A combination of historical fragmentation of forest habitats, mostly for small-scale agriculture, and unsustainable hunting likely drove various populations to the south, east and west of the current population to extinction. This happened prior to the industrial-scale forest conversion that started in the 1970s. Our findings indicate how sensitive P. tapanuliensis is to the combined effects of habitat fragmentation and unsustainable take-off rates. Saving this species will require prevention of any further fragmentation and killings or other removal of animals from the remaining population. Without concerted action to achieve this, the remaining populations of P. tapanuliensis are doomed to become extinct within several orangutan generations.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Demografía/tendencias , Dinámica Poblacional/tendencias , Animales , Demografía/estadística & datos numéricos , Ecosistema , Especies en Peligro de Extinción/estadística & datos numéricos , Bosques , Hominidae , Pongo , Densidad de Población , Dinámica Poblacional/estadística & datos numéricos
7.
PLoS One ; 16(1): e0244719, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33481832

RESUMEN

A fundamental premise of river management is that practitioners understand the resource they are working with. In river management this requires that baseline information is available on the structure, function, health and trajectory of rivers. Such information provides the basis to contextualise, to plan, to be proactive, to prioritise, to set visions, to set goals and to undertake objective, pragmatic, transparent and evidence-based decision making. In this paper we present the State-wide NSW River Styles database, the largest and most comprehensive dataset of geomorphic river type, condition and recovery potential available in Australia. The database is an Open Access product covering over 216,600 km of stream length in an area of 802,000 km2. The availability of the database presents unprecedented opportunities to systematically consider river management issues at local, catchment, regional and state-wide scales, and appropriately contextualise applications in relation to programs at other scales (e.g. internationally)-something that cannot be achieved independent from, or without, such a database. We present summary findings from the database and demonstrate through use of examples how the database has been used in geomorphologically-informed river management. We also provide a cautionary note on the limitations of the database and expert advice on lessons learnt during its development to aid others who are undertaking similar analyses.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Ríos , Australia , Bases de Datos Factuales , Ecosistema , Fenómenos Geológicos , Ríos/química
8.
PLoS One ; 16(1): e0237621, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33503032

RESUMEN

The Pinyon Jay is a highly social, year-round inhabitant of pinyon-juniper and other coniferous woodlands in the western United States. Range-wide, Pinyon Jays have declined ~ 3-4% per year for at least the last half-century. Occurrence patterns and habitat use of Pinyon Jays have not been well characterized across much of the species' range, and obtaining this information is necessary for better understanding the causes of ongoing declines and determining useful conservation strategies. Additionally, it is important to better understand if and how targeted removal of pinyon-juniper woodland, a common and widespread vegetation management practice, affects Pinyon Jays. The goal of this study was to identify the characteristics of areas used by Pinyon Jays for several critical life history components in the Great Basin, which is home to nearly half of the species' global population, and to thereby facilitate the inclusion of Pinyon Jay conservation measures in the design of vegetation management projects. To accomplish this, we studied Pinyon Jays in three widely separated study areas using radio telemetry and direct observation and measured key attributes of their locations and a separate set of randomly-selected control sites using the U. S. Forest Service's Forest Inventory Analysis protocol. Data visualizations, principle components analysis, and logistic regressions of the resulting data indicated that Pinyon Jays used a distinct subset of available pinyon-juniper woodland habitat, and further suggested that Pinyon Jays used different but overlapping habitats for seed caching, foraging, and nesting. Caching was concentrated in low-elevation, relatively flat areas with low tree cover; foraging occurred at slightly higher elevations with generally moderate but variable tree cover; and nesting was concentrated in slightly higher areas with high tree and vegetation cover. All three of these Pinyon Jay behavior types were highly concentrated within the lower-elevation band of pinyon-juniper woodland close to the woodland-shrubland ecotone. Woodland removal projects in the Great Basin are often concentrated in these same areas, so it is potentially important to incorporate conservation measures informed by Pinyon Jay occurrence patterns into existing woodland management paradigms, protocols, and practices.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Cuervos/metabolismo , Animales , Conducta Animal/fisiología , Demografía , Ecosistema , Bosques , Juniperus/crecimiento & desarrollo , Densidad de Población , Árboles , Estados Unidos
9.
PLoS One ; 16(1): e0238669, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33471868

RESUMEN

While the international pet trade and habitat destruction have been extensively discussed as major threats to the survival of the pancake tortoise (Malacochersus tornieri), the impact of climate change on the species remains unknown. In this study, we used species distribution modelling to predict the current and future distribution of pancake tortoises in Zambezian and Somalian biogeographical regions. We used 224 pancake tortoise occurrences obtained from Tanzania, Kenya and Zambia to estimate suitable and stable areas for the pancake tortoise in all countries present in these regions. We also used a protected area network to assess how many of the suitable and stable areas are protected for the conservation of this critically endangered species. Our model predicted the expansion of climatically suitable habitats for pancake tortoises from four countries and a total area of 90,668.75 km2 to ten countries in the future and an area of 343,459.60-401,179.70 km2. The model also showed that a more significant area of climatically suitable habitat for the species lies outside of the wildlife protected areas. Based on our results, we can predict that pancake tortoises may not suffer from habitat constriction. However, the species will continue to be at risk from the international pet trade, as most of the identified suitable habitats remain outside of protected areas. We suggest that efforts to conserve the pancake tortoise should not only focus on protected areas but also areas that are unprotected, as these comprise a large proportion of the suitable and stable habitats available following predicted future climate change.


Asunto(s)
Conservación de los Recursos Naturales/tendencias , Tortugas , África Oriental , Animales , Animales Salvajes , Cambio Climático/estadística & datos numéricos , Conservación de los Recursos Naturales/métodos , Ecosistema , Especies en Peligro de Extinción/estadística & datos numéricos , Especies en Peligro de Extinción/tendencias , Kenia , Modelos Estadísticos , Tanzanía , Zambia
10.
Proc Natl Acad Sci U S A ; 118(2)2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33397723

RESUMEN

Climate shocks can reorganize the social-ecological linkages in food-producing communities, leading to a sudden loss of key products in food systems. The extent and persistence of this reorganization are difficult to observe and summarize, but are critical aspects of predicting and rapidly assessing community vulnerability to extreme events. We apply network analysis to evaluate the impact of a climate shock-an unprecedented marine heatwave-on patterns of resource use in California fishing communities, which were severely affected through closures of the Dungeness crab fishery. The climate shock significantly modified flows of users between fishery resources during the closures. These modifications were predicted by pre-shock patterns of resource use and were associated with three strategies used by fishing community member vessels to respond to the closures: temporary exit from the food system, spillover of effort from the Dungeness crab fishery into other fisheries, and spatial shifts in where crab were landed. Regional differences in resource use patterns and vessel-level responses highlighted the Dungeness crab fishery as a seasonal "gilded trap" for northern California fishing communities. We also detected disparities in climate shock response based on vessel size, with larger vessels more likely to display spatial mobility. Our study demonstrates the importance of highly connected and decentralized networks of resource use in reducing the vulnerability of human communities to climate shocks.


Asunto(s)
Cambio Climático/economía , Conservación de los Recursos Naturales/métodos , Explotaciones Pesqueras/tendencias , Animales , Braquiuros , Clima , Cambio Climático/estadística & datos numéricos , Conservación de los Recursos Naturales/tendencias , Ecosistema , Explotaciones Pesqueras/economía , Humanos , Alimentos Marinos , Mariscos , Estados Unidos
12.
Nature ; 589(7843): 567-571, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33505035

RESUMEN

Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas1-3. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goals4,5: the Living Planet Index (a measure of changes in abundance aggregated from 57 abundance time-series datasets for 18 oceanic shark and ray species) and the Red List Index (a measure of change in extinction risk calculated for all 31 oceanic species of sharks and rays). We find that, since 1970, the global abundance of oceanic sharks and rays has declined by 71% owing to an 18-fold increase in relative fishing pressure. This depletion has increased the global extinction risk to the point at which three-quarters of the species comprising this functionally important assemblage are threatened with extinction. Strict prohibitions and precautionary science-based catch limits are urgently needed to avert population collapse6,7, avoid the disruption of ecological functions and promote species recovery8,9.


Asunto(s)
Organismos Acuáticos/aislamiento & purificación , Biodiversidad , Conservación de los Recursos Naturales , Especies en Peligro de Extinción/estadística & datos numéricos , Océanos y Mares , Tiburones , Rajidae , Animales , Conservación de los Recursos Naturales/legislación & jurisprudencia , Conservación de los Recursos Naturales/métodos , Extinción Biológica , Femenino , Peces , Cadena Alimentaria , Objetivos , Historia del Siglo XX , Historia del Siglo XXI , Dinámica Poblacional/estadística & datos numéricos , Conducta Predatoria , Medición de Riesgo , Desarrollo Sostenible
13.
Biochem Biophys Res Commun ; 535: 6-11, 2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33340766

RESUMEN

No effective cryopreservation technique exists for fish eggs and embryos; thus, the cryopreservation of germ cells (spermatogonia or oogonia) and subsequent generation of eggs and sperm would be an alternative solution for the long-term preservation of piscine genetic resources. Nevertheless, in our previous study using rainbow trout, we showed that recipients transplanted with XY spermatogonia or XX oogonia produced unnatural sex-biased F1 offspring. To overcome these obstacles, we transplanted immature germ cells (XX oogonia or XY spermatogonia; frozen for 33 days) into the body cavities of triploid hatchlings, and the transplanted germ cells possessed a high capacity for differentiating into eggs and sperm in the ovaries and testes of recipients. Approximately 30% of triploid recipients receiving frozen germ cells generated normal salmon that displayed the donor-derived black body color phenotype, although all triploid salmon not receiving transplants were functionally sterile. Furthermore, F1 offspring obtained from insemination of the oogonia-derived eggs and spermatogonia-derived sperm show a normal sex ratio of 1:1 (female:male). Thus, this method presented a critical technique for practical conservation projects for other teleost fish species and masu salmon.


Asunto(s)
Criopreservación/métodos , Oncorhynchus/crecimiento & desarrollo , Oogonios/citología , Oogonios/trasplante , Óvulo/citología , Espermatogonias/citología , Espermatogonias/trasplante , Espermatozoides/citología , Envejecimiento , Animales , Diferenciación Celular , Conservación de los Recursos Naturales/métodos , Femenino , Células Germinativas , Masculino , Oncorhynchus/embriología , Oogonios/metabolismo , Óvulo/metabolismo , Razón de Masculinidad , Espermatogonias/metabolismo , Espermatozoides/metabolismo , Triploidía
14.
PLoS Comput Biol ; 16(12): e1008540, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33370775

RESUMEN

Reasoning about the factors underlying habitat connectivity and the inter-habitat movement of species is essential to many areas of biological inquiry. In order to better describe and understand the ways in which the landscape may support species movement, an increasing amount of research has focused on identification of paths or corridors that may be important in providing connectivity among habitat. The least-cost path problem has proven to be an instrumental analytical tool in this sense. A complicating aspect of such path identification methods is how to best reconcile and integrate the array of criteria or objectives that species may consider in traversal of a landscape. In cases where habitat connectivity is thought to be influenced or guided by multiple objectives, numerous solutions to least-cost path problems can exist, representing tradeoffs between the objectives. In practice though, identification of these solutions can be very challenging and as such, only a small proportion of them are typically examined leading to a weak characterization of habitat connectivity. To address this computational challenge, a multiobjective optimization framework is proposed. A generalizable multiobjective least-cost path model is first detailed. A non-inferior set estimation (MONISE) algorithm for identifying supported efficient solutions to the multiobjective least-cost path model is then described. However, it is well known that unsupported efficient solutions (which are equally important) can also exist, but are typically ignored given that they are more difficult to identify. Thus, to enable the identification of the full set of efficient solutions (supported and unsupported) to the multiobjective model, a multi-criteria labeling algorithm is then proposed. The developed framework is applied to assess different conceptualizations of habitat connectivity supporting amphibian movement in a wetland system. The results highlight the range of tradeoffs in characterizations of connectivity that can exist when multiple objectives are thought to contribute to movement decisions and that the number of unsupported efficient solutions (which are typically ignored) can vastly outweigh that of the supported efficient solutions.


Asunto(s)
Anfibios/fisiología , Simulación por Computador , Ecosistema , Movimiento , Algoritmos , Animales , Conservación de los Recursos Naturales/métodos
15.
PLoS One ; 15(12): e0244440, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33370410

RESUMEN

Effectively communicating risk is critical to reducing conflict in human-wildlife interactions. Using a survey experiment fielded in the midst of contentious public debate over flying fox management in urban and suburban areas of Australia, we find that stories with characters (i.e., narratives) are more effective than descriptive information at mobilizing support for different forms of bat management, including legal protection, relocation, and habitat restoration. We use conditional process analysis to show that narratives, particularly with accompanying images, are effective because they cause emotional reactions that influence risk perception, which in turn drives public opinion about strategies for risk mitigation. We find that prior attitudes towards bats matter in how narrative messages are received, in particular in how strongly they generate shifts in affective response, risk perception, and public opinion. Our results suggest that those with warm prior attitudes towards bats report greater support for bat dispersal when they perceive impacts from bats to be more likely, while those with cool priors report greater support for bat protection when they perceive impacts from bats to be more positive, revealing 1) potential opportunities for targeted messaging to boost public buy-in of proposals to manage risks associated with human-wildlife interactions, and 2) potential vulnerabilities to disinformation regarding risk.


Asunto(s)
Quirópteros , Conservación de los Recursos Naturales/métodos , Narración , Opinión Pública , Distribución Animal , Animales , Australia , Ecosistema , Emociones , Humanos , Evaluación y Mitigación de Riesgos
16.
Nature ; 588(7839): 625-630, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33328640

RESUMEN

Growing populations and agricultural intensification have led to raised riverine nitrogen (N) loads, widespread oxygen depletion in coastal zones (coastal hypoxia)1 and increases in the incidence of algal blooms.Although recent work has suggested that individual wetlands have the potential to improve water quality2-9, little is known about the current magnitude of wetland N removal at the landscape scale. Here we use National Wetland Inventory data and 5-kilometre grid-scale estimates of N inputs and outputs to demonstrate that current N removal by US wetlands (about 860 ± 160 kilotonnes of nitrogen per year) is limited by a spatial disconnect between high-density wetland areas and N hotspots. Our model simulations suggest that a spatially targeted increase in US wetland area by 10 per cent (5.1 million hectares) would double wetland N removal. This increase would provide an estimated 54 per cent decrease in N loading in nitrate-affected watersheds such as the Mississippi River Basin. The costs of this increase in area would be approximately 3.3 billion US dollars annually across the USA-nearly twice the cost of wetland restoration on non-agricultural, undeveloped land-but would provide approximately 40 times more N removal. These results suggest that water quality improvements, as well as other types of ecosystem services such as flood control and fish and wildlife habitat, should be considered when creating policy regarding wetland restoration and protection.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Nitratos/aislamiento & purificación , Nitratos/metabolismo , Humedales , Agricultura , Animales , Conservación de los Recursos Naturales/economía , Política Ambiental/economía , Política Ambiental/tendencias , Restauración y Remediación Ambiental/economía , Restauración y Remediación Ambiental/métodos , Eutrofización , Inundaciones/prevención & control , Mapeo Geográfico , Ríos , Estados Unidos , Calidad del Agua
17.
PLoS One ; 15(12): e0244605, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33378377

RESUMEN

Managing Marine Protected Areas (MPAs) is about managing human behaviours, but decision-making processes have traditionally focussed on ecological aspects, treating social aspects as secondary. It is now becoming more evident that an equal focus on the ecological and social aspects is required. Without the collection of information about social aspect such as impacts and sharing this as well as ecological information with communities, MPAs are at higher risk of opposition and social acceptability problems. This paper explores the development of a wellbeing framework to understand the social aspects, including the impacts of MPAs on the wellbeing of local communities. This research investigates two case study MPAs: Cape Byron and Port Stephens-Great Lakes Marine Parks in New South Wales, Australia. The MPAs are multiple-use and were implemented in 2006 and 2007, respectively. The research began with a review of the literature, followed by fieldwork, including semi-structured qualitative interviews with community members. Through thematic coding of the interview transcripts in light of the literature on assessing the social impacts of MPAs, a community wellbeing framework of domains and associated attributes was developed to investigate social impacts. Our analysis shows; first, local perspectives are crucial to understanding social impacts. Second, understanding social impacts gives insight into the nature of trade-offs that occur in decision-making regarding MPAs. Third, the intangible social impacts experienced by local communities are just as significant as the tangible ones for understanding how MPAs operate. Fourth, governance impacts have been the most influential factor affecting the social acceptability of the case study parks. We argue that failure to address negative social impacts can undermine the legitimacy of MPAs. We propose that the framework will support policymakers to work towards more effective, equitable and socially sustainable MPAs by employing much-needed monitoring of human dimensions of conservation interventions at the community level to shape adaptive management.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Política de Salud , Cambio Social , Animales , Cultura , Toma de Decisiones , Humanos , Biología Marina , Nueva Gales del Sur , Formulación de Políticas
18.
PLoS One ; 15(12): e0244322, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33347496

RESUMEN

The hilly red soil region of southern China suffers from severe soil erosion that has led to soil degradation and loss of soil nutrients. Estimating the content and spatial variability of soil organic carbon (SOC) and soil total nitrogen (STN) and assessing the influence of topography and land-use type on SOC and STN after years of soil erosion control are important for vegetation restoration and ecological reconstruction. A total of 375 topsoil samples were collected from Changting County, and their SOC and STN distributions were studied by using descriptive statistics and geostatistical methods. Elevation, slope, aspect and land-use type were selected to investigate the impacts of natural and human factors on the spatial heterogeneity of SOC and STN. The mean SOC and STN concentrations were 15.85 and 0.98 g kg-1 with moderate spatial variations, respectively. SOC and STN exhibited relatively uniform distributions that decreased gradually from the outside parts to the center of the study area. The SOC and STN contents in the study area were still at moderate and low levels after years of erosion control, which suggests that soil nutrient improvement is a slow process. The lowest SOC and STN values were at lower elevations in the center of Changting County. The results indicated that the SOC and STN contents increased most significantly with elevation and slope due to the influence of topography on the regional natural environment and soil erosion in the eroded hilly region. No significant variations were observed among different slope directions and land-use types.


Asunto(s)
Carbono/análisis , Nitrógeno/análisis , Suelo/química , Agricultura/métodos , China , Conservación de los Recursos Naturales/métodos , Humanos , Erosión del Suelo/prevención & control
19.
PLoS One ; 15(12): e0244318, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33370312

RESUMEN

Inefficiency in urban land use is one of the problems caused by rapid urbanization. The UN Sustainable Development Goals (SDGs) indicator 11.3.1 is designed to test urban land use efficiency. This study employed geospatial and statistical data to compute land use efficiencies from 1990 to 2015 with five 5-year and ten 15-year intervals in Wukang, center of Deqing County, China. A flowchart was designed to extract the built-up lands from multiple data sources. The produced built-up lands were demonstrated to provide good accuracy by constructing an error matrix between the extracted and manually interpreted built-up lands as classified and reference images, respectively. By using the model provided by UN metadata to calculate SDG 11.3.1, the land use efficiencies from 1990 to 2015 were identified in Wukang. Our results indicate that the land use efficiency in Deqing County center is lower than the average of cities around the world, primarily because our in-situ study focused on a county center with larger rural regions than urban areas. Over the long term, urban land use becomes denser as the population grows, which will have a positive impact on the sustainability of urban development. This work is helpful for the local government to balance urban land consumption and population growth.


Asunto(s)
Desarrollo Sostenible/economía , Remodelación Urbana/métodos , Urbanización/tendencias , China , Ciudades , Conservación de los Recursos Naturales/métodos , Conservación de los Recursos Naturales/tendencias , Humanos , Modelos Teóricos , Crecimiento Demográfico , Desarrollo Sostenible/tendencias , Población Urbana/tendencias , Remodelación Urbana/tendencias
20.
PLoS One ; 15(12): e0244289, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33382710

RESUMEN

In the field of forestry, one of the most economically important ecosystem service is the provision of timber. The need to calculate the economic effects of forest management in the short, medium, and long term is increasing. Forest operations or timber harvesting, which comprises felling, processing, and transport of trees or timber, are responsible for a large part of the costs and environmental impacts associated to forest management or enterprises. From a decision maker's perspective, it is essential to estimate working productivity and production costs under given operating conditions before any operation is conducted. This work addresses the lack of a valid collection of models that allows estimating time, productivities, and costs of labor and machinery for the most important forest operations in forest stands under Central European conditions. To create such models, we used data from forest enterprises, manual time studies, and the literature. This work presents a decision support tool that estimates the wood harvesting productivities of 12 different kinds of forest operations under Central European conditions. It includes forest operations using chainsaws, harvesters, skidders, forwarders, chippers, cable and tower yarders, and helicopters. In addition, the tool covers three models for wood volume estimation. The tool is written in Java and available open-source under the Apache License. This work shows how the tool can be used by describing its graphical user interface (GUI) and its application programming interface (API) that facilitates bulk processing of scientific data. Carefully selected default values allow estimations without knowing all input variables in detail. Each model is accompanied by an in-depth documentation where the forest operation, input variables, formulas, and statistical background are given. We conclude that HeProMo is a very useful tool for applications in forest practice, research, and teaching.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Predicción/métodos , Agricultura Forestal/métodos , Técnicas de Apoyo para la Decisión , Ecosistema , Eficiencia , Agricultura Forestal/economía , Bosques , Modelos Teóricos , Árboles , Madera
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