1,721,052 research outputs found
High resolution land use maps from 1960 to 2100
No full textAnthropogenic land-use and land-cover change is a major driver of climate change and biodiversity loss. Land-use and land-cover change also leads to changes in the spatial pattern of Earth’s landscapes, which have further negative impacts on environmental processes. For example, deforestation can increase the distance between forest patches, making it harder for species to move between them. Harmonized land-use and land-cover datasets contain standardized maps of global land use and land cover through time, without any gaps or sudden changes between historic and future periods. Harmonized datasets are important for addressing the negative consequences of land-use and land-cover change because they are used in environmental models to predict its impacts on processes such as carbon emissions and species movement. However, existing harmonized datasets do not project the spatial pattern of land-use and land-cover change into the future and have coarse resolutions that do not match the fine scales on which environmental processes occur. We present a high-resolution, global-scale harmonized land-use and land-cover dataset for five future scenarios that spans the period 1960–2100. The spatial pattern of land-use and land-cover change was accounted for when generating the future maps to ensure that they have realistic spatial patterns. This new dataset will be suitable for integration with a range of environmental models, such as those that model biodiversity, climate, and fire, and therefore offers an important tool for understanding the effects of land-use and land-cover change and developing solutions to environmental challenges
Simulating different strategies to control the invasive tree Ligustrum lucidum using the RangeShifter platform
No full textThese folders contain all the inputs (batch files) to simulate alternative strategies for containing the invasion of the Asian tree Ligustrum lucidum at the expansion front. The simulations were conducted utilising a customised version of the individual-based spatially explicit modelling platform RangeShifter v2.0 (Bocedi et al., 2021; https://rangeshifter.github.io/). Across different sets of simulations, we varied the number of life stages and sites targeted. We additionally investigated how changing the management strategy over time affected outcomes. A total of 3 simulation experiments were carried out. The work was carried out as part of the Latin American Biodiversity Programme as part of the Newton Fund (NE/S011641/1), with contributions from NERC (UK), the Argentine National Scientific & Technical Research Council (CONICET,-201974-APN-DIR#CONICET) and 2022GCBCCONTAIN.- Invasive alien species management to decrease impacts on biodiversity, rural poverty and carbon storage -Folder 1: Parametrization of the Individual Base Model -Folder 2: Parametrization of Experiment 1: removing different life stages and varying the number of cells targeted each year for 30 years -Folder 3: Parametrization of Experiment 2: removing all stages (S1 to S4) to evaluate the effect of varying the number of cells targeted per year -Folder 4: Parametrization of Experiment 3: switching from removing all stages to removing only S1 and S2 after five years of removal would maintain effective control of the population for 15 yearsFil: Montti, Lia Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Palmer, Stephen C.F.. University of Aberdeen; Reino UnidoFil: Powell, Priscila Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Burslem, David F.R.P.. University of Aberdeen; Reino UnidoFil: Travis, Justin M.J.. University of Aberdeen; Reino UnidoFil: Ponchon, Aurore. University of Aberdeen; Reino Unid
Disturbing hypotheses in tropical forests
No full textThe intermediate disturbance hypothesis (IDH) is a controversial explanation for the maintenance of tropical forest tree diversity, but empirical tests of it are rare. Two data intensive evaluations have recently yielded contradictory outcomes: one for and one against the IDH. This article proposes that the explanation for these results lies in the subtleties of divergent interpretations and approaches, and in the different characteristics of the study sites. The apparent simplicity of the IDH is deceptive, because a range of distinct phenomena is involved, each of which can be defined and examined. Recent developments offer exciting opportunities for a deeper comprehension of how disturbance influences forest diversity
Global assessment of landscape pattern changes from 1992 to 2020
Full text linkContextChanges in landscape patterns, which refer to the composition and spatial configuration of land use and land cover (LULC) classes in a landscape, can have negative impacts on biodiversity and environmental processes such as carbon cycles. Such impacts are both dependent on the spatial extent of changes and which LULC classes are affected, but previous global-scale landscape pattern assessments have focused on single LULC classes or landscape-level measurements only. A comprehensive, multiscale analysis across multiple LULC types is therefore key for understanding the full impact of landscape pattern change on the environment.ObjectivesWe assessed global-scale change in landscape patterns for six LULC classes from the HILDA+ dataset (urban, cropland, pasture/rangeland, forest, unmanaged grass/shrubland, and sparse/no vegetation) between 1992 and 2020.MethodsSix class-level landscape metrics with predictable scaling behaviour across landscape extents were calculated at global scale for each LULC class and year. Landscape metrics were quantified for five landscape extents (100, 400, 1600, 6400 and 25,600 km2). Trends in landscape metrics were evaluated and linked to changes in LULC composition (area) and configuration over time.ResultsUnmanaged grass/shrubland LULC expanded in area and showed increased number of patches, edge length, and complexity in shapes, while pasture/rangeland and forest LULC tended to decline in area, number of patches, and edge length. Even though there was high spatial heterogeneity in landscape pattern change for all LULC classes, neighbouring 100 km2 landscapes often showed the same directional change in area and fragmentation.ConclusionsGlobal landscape pattern change was highly variable for all LULC classes between 1992 and 2020, suggesting that drivers of LULC change act on local to regional scales. We expect that the multiscale global dataset of landscape metrics generated here will have future applications in understanding the drivers of landscape pattern change and its environmental impacts
Phosphorus acquisition and canopy dominance in tropical and subtropical forests:response to Brearley et al.
No full textSymbiotic control of canopy dominance in subtropical and tropical forests
No full textSubtropical and tropical forests in Asia often comprise canopy dominant trees that form symbioses with ectomycorrhizal fungi, and species-rich understorey trees that form symbioses with arbuscular mycorrhizal fungi. We propose a virtuous phosphorus acquisition hypothesis to explain this distinct structure. The hypothesis is based on (i) seedlings being rapidly colonised by ectomycorrhizal fungi from established mycelial networks that generates positive feedback and resistance to pathogens, (ii) ectomycorrhizal fungi having evolved a suite of morphological, physiological, and molecular traits to enable them to capture phosphorus from a diversity of chemical forms, including organic forms, and (iii) allocation of photosynthate carbon from adult host plants to provide the energy needed to undertake these processes
Phosphorus acquisition and canopy dominance in tropical and subtropical forests : response to Brearley et al.
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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