The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform

Geoffrey B West - One of the best experts on this subject based on the ideXlab platform.

  • allometric scaling of plant energetics and Population Density
    Nature, 1998
    Co-Authors: James H. Brown, Geoffrey B West, Brian J Enquist
    Abstract:

    Scaling relationships describing variation in Population Density with body size in ecological communities, such as the thinning-law in plant ecology, can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, the same as metabolic rates of animals. We use this relationship to develop a mechanistic model for Density-mass relationships in resource-limited plants. It predicts that average plant size should scale as the -4/3 power of maximum Population Density, in agreement with empirical evidence and comparable relationships in animals but significantly less than the -3/2 power predicted by geometric models. Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of Population Density and other ecological and evolutionary phenomena, including the fact that resource allocation among species in ecosystems is independent of body size. To appear in Nature 395: 163-165, 1998.

  • Allometric scaling of plant energetics and Population Density
    Nature, 1998
    Co-Authors: Brian J Enquist, James H. Brown, Geoffrey B West
    Abstract:

    Scaling relationships that describe variation in Population Density with body size in ecological communities, such as the thinning law in plant ecology(1-3), can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, which is the same as metabolic rates of animals(4-7). Here we use this relationship to develop a mechanistic model for relationships between Density and mass in resource-limited plants. It predicts that average plant size should scale as the -4/3 power of maximum Population Density, in agreement with empirical evidence and comparable relationships in animals(5,6,8), but significantly less than the -3/2 power predicted by geometric models(1). Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of Population Density and other ecological and evolutionary phenomena, including the finding that resource allocation among species in ecosystems is independent of body size(5,6,8).

Brian J Enquist - One of the best experts on this subject based on the ideXlab platform.

  • allometric scaling of plant energetics and Population Density
    Nature, 1998
    Co-Authors: James H. Brown, Geoffrey B West, Brian J Enquist
    Abstract:

    Scaling relationships describing variation in Population Density with body size in ecological communities, such as the thinning-law in plant ecology, can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, the same as metabolic rates of animals. We use this relationship to develop a mechanistic model for Density-mass relationships in resource-limited plants. It predicts that average plant size should scale as the -4/3 power of maximum Population Density, in agreement with empirical evidence and comparable relationships in animals but significantly less than the -3/2 power predicted by geometric models. Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of Population Density and other ecological and evolutionary phenomena, including the fact that resource allocation among species in ecosystems is independent of body size. To appear in Nature 395: 163-165, 1998.

  • Allometric scaling of plant energetics and Population Density
    Nature, 1998
    Co-Authors: Brian J Enquist, James H. Brown, Geoffrey B West
    Abstract:

    Scaling relationships that describe variation in Population Density with body size in ecological communities, such as the thinning law in plant ecology(1-3), can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, which is the same as metabolic rates of animals(4-7). Here we use this relationship to develop a mechanistic model for relationships between Density and mass in resource-limited plants. It predicts that average plant size should scale as the -4/3 power of maximum Population Density, in agreement with empirical evidence and comparable relationships in animals(5,6,8), but significantly less than the -3/2 power predicted by geometric models(1). Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of Population Density and other ecological and evolutionary phenomena, including the finding that resource allocation among species in ecosystems is independent of body size(5,6,8).

James H. Brown - One of the best experts on this subject based on the ideXlab platform.

  • allometric scaling of plant energetics and Population Density
    Nature, 1998
    Co-Authors: James H. Brown, Geoffrey B West, Brian J Enquist
    Abstract:

    Scaling relationships describing variation in Population Density with body size in ecological communities, such as the thinning-law in plant ecology, can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, the same as metabolic rates of animals. We use this relationship to develop a mechanistic model for Density-mass relationships in resource-limited plants. It predicts that average plant size should scale as the -4/3 power of maximum Population Density, in agreement with empirical evidence and comparable relationships in animals but significantly less than the -3/2 power predicted by geometric models. Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of Population Density and other ecological and evolutionary phenomena, including the fact that resource allocation among species in ecosystems is independent of body size. To appear in Nature 395: 163-165, 1998.

  • Allometric scaling of plant energetics and Population Density
    Nature, 1998
    Co-Authors: Brian J Enquist, James H. Brown, Geoffrey B West
    Abstract:

    Scaling relationships that describe variation in Population Density with body size in ecological communities, such as the thinning law in plant ecology(1-3), can be explained in terms of how individuals use resources as a function of their size. Data for rates of xylem transport as a function of stem diameter show that rates of resource use in individual plants scale as approximately the 3/4 power of body mass, which is the same as metabolic rates of animals(4-7). Here we use this relationship to develop a mechanistic model for relationships between Density and mass in resource-limited plants. It predicts that average plant size should scale as the -4/3 power of maximum Population Density, in agreement with empirical evidence and comparable relationships in animals(5,6,8), but significantly less than the -3/2 power predicted by geometric models(1). Our model implies that fundamental constraints on metabolic rate are reflected in the scaling of Population Density and other ecological and evolutionary phenomena, including the finding that resource allocation among species in ecosystems is independent of body size(5,6,8).

Catherine Linard - One of the best experts on this subject based on the ideXlab platform.

  • the impact of urbanization and Population Density on childhood plasmodium falciparum parasite prevalence rates in africa
    Malaria Journal, 2017
    Co-Authors: Caroline W Kabaria, Marius Gilbert, Abdisalan M Noor, Robert W Snow, Catherine Linard
    Abstract:

    Although malaria has been traditionally regarded as less of a problem in urban areas compared to neighbouring rural areas, the risk of malaria infection continues to exist in densely populated, urban areas of Africa. Despite the recognition that urbanization influences the epidemiology of malaria, there is little consensus on urbanization relevant for malaria parasite mapping. Previous studies examining the relationship between urbanization and malaria transmission have used products defining urbanization at global/continental scales developed in the early 2000s, that overestimate actual urban extents while the Population estimates are over 15 years old and estimated at administrative unit level. This study sought to discriminate an urbanization definition that is most relevant for malaria parasite mapping using individual level malaria infection data obtained from nationally representative household-based surveys. Boosted regression tree (BRT) modelling was used to determine the effect of urbanization on malaria transmission and if this effect varied with urbanization definition. In addition, the most recent high resolution Population distribution data was used to determine whether Population Density had significant effect on malaria parasite prevalence and if so, could Population Density replace urban classifications in modelling malaria transmission patterns. The risk of malaria infection was shown to decline from rural areas through peri-urban settlements to urban central areas. Population Density was found to be an important predictor of malaria risk. The final boosted regression trees (BRT) model with urbanization and Population Density gave the best model fit (Tukey test p value <0.05) compared to the models with urbanization only. Given the challenges in uniformly classifying urban areas across different countries, Population Density provides a reliable metric to adjust for the patterns of malaria risk in densely populated urban areas. Future malaria risk models can, therefore, be improved by including both Population Density and urbanization which have both been shown to have significant impact on malaria risk in this study.

Piotr Tryjanowski - One of the best experts on this subject based on the ideXlab platform.

  • high urban Population Density of birds reflects their timing of urbanization
    Oecologia, 2012
    Co-Authors: Anders Pape Moller, Mario Diaz, Einar Flenstedjensen, Tomas Grim, Juan Diego Ibanezalamo, Jukka Jokimaki, Raivo Mand, Gabor Marko, Piotr Tryjanowski
    Abstract:

    Living organisms generally occur at the highest Population Density in the most suitable habitat. Therefore, invasion of and adaptation to novel habitats imply a gradual increase in Population Density, from that at or below what was found in the ancestral habitat to a Density that may reach higher levels in the novel habitat following adaptation to that habitat. We tested this prediction of invasion biology by analyzing data on Population Density of breeding birds in their ancestral rural habitats and in matched nearby urban habitats that have been colonized recently across a continental latitudinal gradient. We esti- mated Population Density in the two types of habitats using extensive point census bird counts, and we obtained information on the year of urbanization when Population Density in urban habitats reached levels higher than that of the ancestral rural habitat from published records and estimates by experienced ornithologists. Both the differ- ence in Population Density between urban and rural habitats and the year of urbanization were significantly repeatable when analyzing multiple Populations of the same species across Europe. Population Density was on average 30 % higher in urban than in rural habitats, although Density reached as much as 100-fold higher in urban habitats in some species. Invasive urban bird species that colonized urban environments over a long period achieved the largest increases in Population Density compared to their ancestral rural habitats. This was independent of whether species were anciently or recently urbanized, providing a unique cross-validation of timing of urban invasions. These results