191,839 research outputs found
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Climate and plant community diversity in space and time.
Climate strongly shapes plant diversity over large spatial scales, with relatively warm and wet (benign, productive) regions supporting greater numbers of species. Unresolved aspects of this relationship include what causes it, whether it permeates to community diversity at smaller spatial scales, whether it is accompanied by patterns in functional and phylogenetic diversity as some hypotheses predict, and whether it is paralleled by climate-driven changes in diversity over time. Here, studies of Californian plants are reviewed and new analyses are conducted to synthesize climate-diversity relationships in space and time. Across spatial scales and organizational levels, plant diversity is maximized in more productive (wetter) climates, and these consistent spatial relationships are mirrored in losses of taxonomic, functional, and phylogenetic diversity over time during a recent climatic drying trend. These results support the tolerance and climatic niche conservatism hypotheses for climate-diversity relationships, and suggest there is some predictability to future changes in diversity in water-limited climates
Bridging the biodiversity data gaps: Recommendations to meet usersâ data needs
A strong case has been made for freely available, high quality data on species occurrence, in order to track changes in biodiversity. However, one of the main issues surrounding the provision of such data is that sources vary in quality, scope, and accuracy. Therefore publishers of such data must face the challenge of maximizing quality, utility and breadth of data coverage, in order to make such data useful to users. Here, we report a number of recommendations that stem from a content need assessment survey conducted by the Global Biodiversity Information Facility (GBIF). Through this survey, we aimed to distil the main user needs regarding biodiversity data. We find a broad range of recommendations from the survey respondents, principally concerning issues such as data quality, bias, and coverage, and extending ease of access. We recommend a candidate set of actions for the GBIF that fall into three classes: 1) addressing data gaps, data volume, and data quality, 2) aggregating new kinds of data for new applications, and 3) promoting ease-of-use and providing incentives for wider use. Addressing the challenge of providing high quality primary biodiversity data can potentially serve the needs of many international biodiversity initiatives, including the new 2020 biodiversity targets of the Convention on Biological Diversity, the emerging global biodiversity observation network (GEO BON), and the new Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)
From buildings to cities: techniques for the multi-scale analysis of urban form and function
The built environment is a significant factor in many urban processes, yet direct measures of built form are
seldom used in geographical studies. Representation and analysis of urban form and function could provide
new insights and improve the evidence base for research. So far progress has been slow due to limited data
availability, computational demands, and a lack of methods to integrate built environment data with
aggregate geographical analysis. Spatial data and computational improvements are overcoming some of
these problems, but there remains a need for techniques to process and aggregate urban form data. Here we
develop a Built Environment Model of urban function and dwelling type classifications for Greater
London, based on detailed topographic and address-based data (sourced from Ordnance Survey
MasterMap). The multi-scale approach allows the Built Environment Model to be viewed at fine-scales for
local planning contexts, and at city-wide scales for aggregate geographical analysis, allowing an improved
understanding of urban processes. This flexibility is illustrated in the two examples, that of urban function
and residential type analysis, where both local-scale urban clustering and city-wide trends in density and
agglomeration are shown. While we demonstrate the multi-scale Built Environment Model to be a viable
approach, a number of accuracy issues are identified, including the limitations of 2D data, inaccuracies in
commercial function data and problems with temporal attribution. These limitations currently restrict the
more advanced applications of the Built Environment Model
Quantitative Perspectives on Fifty Years of the Journal of the History of Biology
Journal of the History of Biology provides a fifty-year long record for
examining the evolution of the history of biology as a scholarly discipline. In
this paper, we present a new dataset and preliminary quantitative analysis of
the thematic content of JHB from the perspectives of geography, organisms, and
thematic fields. The geographic diversity of authors whose work appears in JHB
has increased steadily since 1968, but the geographic coverage of the content
of JHB articles remains strongly lopsided toward the United States, United
Kingdom, and western Europe and has diversified much less dramatically over
time. The taxonomic diversity of organisms discussed in JHB increased steadily
between 1968 and the late 1990s but declined in later years, mirroring broader
patterns of diversification previously reported in the biomedical research
literature. Finally, we used a combination of topic modeling and nonlinear
dimensionality reduction techniques to develop a model of multi-article fields
within JHB. We found evidence for directional changes in the representation of
fields on multiple scales. The diversity of JHB with regard to the
representation of thematic fields has increased overall, with most of that
diversification occurring in recent years. Drawing on the dataset generated in
the course of this analysis, as well as web services in the emerging digital
history and philosophy of science ecosystem, we have developed an interactive
web platform for exploring the content of JHB, and we provide a brief overview
of the platform in this article. As a whole, the data and analyses presented
here provide a starting-place for further critical reflection on the evolution
of the history of biology over the past half-century.Comment: 45 pages, 14 figures, 4 table
Environmental drivers of large-scale movements of baleen whales in the mid-North Atlantic Ocean
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Perez-Jorge, S., Tobena, M., Prieto, R., Vandeperre, F., Calmettes, B., Lehodey, P., & Silva, M. A. Environmental drivers of large-scale movements of baleen whales in the mid-North Atlantic Ocean. Diversity and Distributions, 00, (2020): 1-16, doi:10.1111/ddi.13038.Aim
Understanding the environmental drivers of movement and habitat use of highly migratory marine species is crucial to implement appropriate management and conservation measures. However, this requires quantitative information on their spatial and temporal presence, which is limited in the high seas. Here, we aimed to gain insights of the essential habitats of three baleen whale species around the midâNorth Atlantic (NA) region, linking their largeâscale movements with information on oceanographic and biological processes.
Location
MidâNA Ocean.
Methods
We present the first study combining data from 31 satellite tracks of baleen whales (15, 10 and 6 from fin, blue and sei whales, respectively) from March to July (2008â2016) with data on remotely sensed oceanography and midâ and lower trophic level biomass derived from the spatial ecosystem and population dynamics model (SEAPODYM). A Bayesian switching stateâspace model was applied to obtain regular tracks and correct for location errors, and pseudoâabsences were created through simulated positions using a correlated random walk model. Based on the tracks and pseudoâabsences, we applied generalized additive mixed models (GAMMs) to determine the probability of occurrence and predict monthly distributions.
Results
This study provides the most detailed research on the spatioâtemporal distribution of baleen whales in the midâNA, showing how dynamic biophysical processes determine their habitat preference. Movement patterns were mainly influenced by the interaction of temperature and the lower trophic level biomass; however, this relationship differed substantially among species. Bestâfit models suggest that movements of whales migrating towards more productive areas in northern latitudes were constrained by depth and eddy kinetic energy.
Main conclusions
These novel insights highlight the importance of integrating telemetry data with spatially explicit prey models to understand which factors shape the movement patterns of highly migratory species across large geographical scales. In addition, our outcomes could contribute to inform management of anthropogenic threats to baleen whales in sparsely surveyed region.We are very grateful to ClĂĄudia Oliveira, Irma CascĂŁo, Maria JoĂŁo Cruz, Miriam Romagosa and many volunteers, skilled skippers, crew and spotters that participated in the tagging fieldwork. This work was supported by Fundação para a CiĂȘncia e Tecnologia (FCT), Azores 2020 Operational Programme and Fundo Regional da CiĂȘncia e Tecnologia (FRCT) through research projects FCTâExploratory project (IF/00943/2013/CP1199/CT0001), TRACE (PTDC/MAR/74071/2006) and MAPCET (M2.1.2/F/012/2011) coâfunded by FEDER, COMPETE, QREN, POPH, ESF, ERDF, Portuguese Ministry for Science and Education, and Proconvergencia Açores/EU Program. We also acknowledge funds provided by FCT to MARE, through the strategic project UID/MAR/04292/2013. SPJ was supported by a postdoctoral grant (REF.GREENUP/001â2016), MT by a DRCT doctoral grant (M3.1.a/F/028/2015), MAS by an FCTâInvestigator contract (IF/00943/2013), FV by an FCT Investigator contract (CEECIND/03469/2017) and RP by an FCT postdoctoral grant (SFRH/BPD/108007/2015). LMTL modelling work has been supported by the CMEMS Service Evolution GREENUP project, funded by Mercator Ocean. We are grateful to Elliott Hazen for offering guidance and advice, and to two anonymous referees whose comments greatly improved this work
Understanding drivers of species distribution change: a trait-based approach
The impacts of anthropogenic environmental change on biodiversity are well documented, with
threats such as habitat loss and climate change identified as causes of change in species
distributions. The high degree of variation in responses of species to environmental change can be
partly explained through comparative analyses of species traits. I carried out a phylogenetically
informed trait-based analysis of plant range change in Britain, discovering that traits associated with
competitive ability and habitat specialism both explained variation in range changes. Competitive,
habitat generalists out-perform
ed
species specialised to nutrient-poor conditions; a result which can
be attributed to the impact of agricultural intensification in Britain. A limitation of the comparative
approach is that the models do not directly test the impact of environmental change on species
distribution patterns, but instead infer potential impacts.
I tested the potential of comparative
analyses from a spatial context by conducting a spatial analysis of plant distribution change in Britain, examining the direct impact of environmental change on the spatial distribution of the trait characteristics of species that have gone locally extinct. I discovered a loss of species associated with nitrogen poor soils in regions that had an increase
in arable land cover, a result that supports
the results from the trait-based analysis of plant range change and demonstrates that comparative studies can accurately infer drivers of distribution change. I found that the cross-region transferability of trait-based models of range change to be related to land cover similarity,
highlighting that the trait-based approach is dependent on a regional context. Additionally, I discovered that traits derived from distribution data were significant predictors of range shift across many taxonomic groups, out-performing traditional life history traits. This thesis highlights the potential of the data accumulated through the increased public participation in biological recording to address previously unanswerable ecological research questions.Open Acces
Phytoplankton Community and Algal Toxicity at a Recurring Bloom in Sullivan Bay, Kabetogama Lake, Minnesota, USA
Kabetogama Lake in Voyageurs National Park, Minnesota, USA suffers from recurring late summer algal blooms that often contain toxin-producing cyanobacteria. Previous research identified the toxin microcystin in blooms, but we wanted to better understand how the algal and cyanobacterial community changed throughout an open water season and how changes in community structure were related to toxin production. Therefore, we sampled one recurring bloom location throughout the entire open water season. The uniqueness of this study is the absence of urban and agricultural nutrient sources, the remote location, and the collection of samples before any visible blooms were present. Through quantitative polymerase chain reaction (qPCR), we discovered that toxin-forming cyanobacteria were present before visible blooms and toxins not previously detected in this region (anatoxin-a and saxitoxin) were present, indicating that sampling for additional toxins and sampling earlier in the season may be necessary to assess ecosystems and human health risk
Bipolar flaking as a component of a supraregional lithic resource base: A comparative study of cores from the Pampean and Northcentral Patagonian Atlantic coasts (Argentina)
Several authors argue that bipolar technology is an expeditious and versatile strategy, efficient for the reduction of small nodules. However, few studies analyze the use of bipolar reduction in relation to the lithic environmental supply. At the Pampean and Patagonian maritime coast, the technique has been widely recorded and seems to be conspicuous in indigenous populations that occupied coastal areas. With the aim of assessing and comparing the application of bipolar reduction, 196 nuclei recovered from sites of diverse chronologies in the Pampean and northcentral Patagonic coasts were analyzed. The use of the bipolar technique was observed in relation to the lithic environmental structure, the size of nodules and their raw material. The results revealed high frequencies of bipolar nuclei at the Pampean coast (87%) and moderate frequencies at the northcentral Patagonic coast (39%). It was determined that the variables that influenced the application of bipolar techniques the most were the small size of the nodules and their rounded shape, generally thick, and without flat surfaces. As for raw material quality, the technique was applied on good to medium quality rocks at the Pampean coast, while in the northcentral coast it was exclusively applied on pebbles and cobbles of superior qualities (very good to excellent). The differences observed are most likely linked with technological choices made by different coastal populations to make the best use of widely available local rocks.Fil: Banegas, Anahi. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Bonomo, Mariano. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Gomez Otero, Julieta. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
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State and trait characteristics of anterior insula time-varying functional connectivity.
The human anterior insula (aINS) is a topographically organized brain region, in which ventral portions contribute to socio-emotional function through limbic and autonomic connections, whereas the dorsal aINS contributes to cognitive processes through frontal and parietal connections. Open questions remain, however, regarding how aINS connectivity varies over time. We implemented a novel approach combining seed-to-whole-brain sliding-window functional connectivity MRI and k-means clustering to assess time-varying functional connectivity of aINS subregions. We studied three independent large samples of healthy participants and longitudinal datasets to assess inter- and intra-subject stability, and related aINS time-varying functional connectivity profiles to dispositional empathy. We identified four robust aINS time-varying functional connectivity modes that displayed both "state" and "trait" characteristics: while modes featuring connectivity to sensory regions were modulated by eye closure, modes featuring connectivity to higher cognitive and emotional processing regions were stable over time and related to empathy measures
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