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This map shows Census boundaries and other features on a simple, mostly white basemap. The map displays the 2009 TIGER data. This map is designed to complement colorful basemaps and thematic layers, such as Census demographics. It is intended for census experts and the general public alike. This map shows Census boundaries and other features on a simple, mostly white basemap. The map displays the 2009 TIGER data. This map is designed to complement colorful basemaps and thematic layers, such as Census demographics. It is intended for census experts and the general public alike. The map includes water features, railway, roads, and administrative boundaries (city and town limits, metropolitan statistical...
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Montana Population in persons per square mile from the 2000 Census. This data is a smoothed-over representation of Montana's population density surface, designed to emphasize small areas with high population density. It was derived from U.S. Census Bureau 2000 TIGER files and population counts. The original data was resampled to a 100-meter grid, smoothed, and the highest resulting density of the 100-meter cells in each 1-kilometer grid cell was assigned to the cell. When comparing this data set to the similar data set available from NRIS for the 1990 Census, it is important to realize that the change of population density at a location is likely to be the result of a change in the configuration of the Census...
We estimated global cyanobacterial biomass in the main reservoirs of cyanobacteria on Earth: marine and freshwater plankton, arid land soil crusts, and endoliths. Estimates were based on typical population density values as measured during our research, or as obtained from literature surveys, which were then coupled with data on global geographical area coverage. Among the marine plankton, the global biomass of Prochlorococcus reaches 120 × 10^12 grams of carbon (g C), and that of Synechoccus some 43 × 10^12 g C. This makes Prochlorococcus and Synechococcus, in that order, the most abundant cyanobacteria on Earth. Tropical marine blooms of Trichodesmium account for an additional 10 × 10^12 g C worldwide. In terrestrial...
We examined changes in small mammal habitat and densities of four small mammal species, including deer mice (Peromyscus maniculatus), gray-collared chipmunks (Tamias cinereicollis), golden-mantled ground squirrels (Spermophilus lateralis), and Mexican woodrats (Neotoma mexicana), 2?3 years after thinning and prescribed fire treatments in ponderosa pine (Pinus ponderosa) forests of northern Arizona, US. These treatments were designed to simultaneously reduce high-severity fire risk while returning forests to conditions more representative of pre-European settlement structure and function. Treatments resulted in changes in important components of small mammal habitat, including increased herbaceous vegetation, decreased...
Gunnison's prairie dogs (Cynomys gunnisoni) are social North American ground squirrels whose social system has been shown to vary with food resource distributions, as predicted by the habitat variability-mating system model. We expanded this model to include the effects of variations in population densities, in addition to resource distributions, on both the social system and the individual mating strategies of Gunnison's prairie dogs. Specifically, we predicted that monogamy would be associated with uniform resources, regardless of population density, giving way to polygyny with increasing resource patchiness at intermediate densities, and to multiple males and females at high population densities. In addition,...
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Human density was calculated from 2010 US Census Bureau's P2 dataset to determine the population per square kilometer.2 - 27 persons/km2 = moderate> 27 persons/km2 = lower quality
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Human density was calculated from 2010 US Census Bureau's P2 dataset to determine the population per square kilometer.2 - 27 persons/km2 = moderate> 27 persons/km2 = lower quality
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Montana Population in persons per square mile. Derived from 1990 U.S. Census Bureau TIGER files and population counts. The original data was smoothed, and the highest resulting density in each 1-kilometer grid cell was assigned to the cell. See /gis2/montwork/cmp/94/94nris98e.aml for exact method used to create this grid.
This is a map of populated areas with population density greater than or equal to 1 individual/ha (i.e., rural/exurban but including suburban and urban as defined by Marzluff et al. 2001) as determined from U.S. Census data corrected for public lands.
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This thematic map presents the population density in the United States in 2010. Population density is the number of people per square mile. It is calculated by dividing the total population count of geographic feature by the area of the feature, in square miles. The area is calculated from the geometry of the geographic feature in projected coordinates. The geography depicts states at greater than 25m scale, counties at 1m to 25m scale, Census Tracts at 250k to 1m scale, and Census Block Groups at less than 250k scale. The map has been designed to be displayed with semi-transparency of about 50% for overlay on other base maps, which is reflected in the legend for the map. For more information on this map, visit...
This is a map of populated areas with population density greater than or equal to 1 individual/ha (i.e., rural/exurban but including suburban and urban as defined by Marzluff et al. 2001) as determined from U.S. Census data corrected for public lands.
We attempted a complete review of the empirical literature on effects of roads and traffic on animal abundance and distribution. We found 79 studies, with results for 131 species and 30 species groups. Overall, the number of documented negative effects of roads on animal abundance outnumbered the number of positive effects by a factor of 5; 114 responses were negative, 22 were positive, and 56 showed no effect. Amphibians and reptiles tended to show negative effects. Birds showed mainly negative or no effects, with a few positive effects for some small birds and for vultures. Small mammals generally showed either positive effects or no effect, mid-sized mammals showed either negative effects or no effect, and large...
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Synopsis: This document details the Milk River Basin project, designed to produce innovative approaches to multi-species management in Southern Alberta. The Milk River basin contains a variety of ‘sensitive’, ‘at risk’, and ‘may be at risk’ species. The process of prioritizing the landscape for conservation and stewardship was driven by species inventories to identify known locations, and Habitat Suitability Index (HSI) models to delimit suitable key habitat for the 17 selected species. The construction of the models was limited to the available variables and resolution of the databases. For MULTISAR: the Milk River Basin Project area this was the quarter section, the resolution of the Native Prairie Vegetation...
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This dataset consists of three raster datasets representing population density for the years 1990, 2000, and 2010. All three rasters are based on block-level census geography data. The 1990 and 2000 data are derived from data normalized to 2000 block boundaries, while the 2010 data are based on 2010 block boundaries. The 1990 and 2000 data are rasters at 100-meter (m) resolution, while the 2010 data are at 60-m resolution. See details about each dataset in the specific metadata for each raster.
Regional economic impact assessment (REIA) and social impact assessment (SIA) are methodologically close, since REIA provides predictions of change in employment both directly and indirectly resulting from a project, thereby giving some indication of future population changes, derived demand for social services and infrastructure, and the likely regional social mix. There are, however, a number of theoretical difficulties with conventional REIAs. As extrapolations they normally avoid discussion of processes of structural change, which could result in substantial changes within the time horizon of a project. Another issue is the justification for including secondary project impacts in assessing a project's worth....
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Population Density, 2000Gridded Population of the World, Version 3 (GPWv3) consists of estimates of human population for the years 1990, 1995, and 2000 by 2.5 arc-minute grid cells and associated data sets dated circa 2000. A proportional allocation gridding algorithm, utilizing more than 300,000 national and sub-national administrative units, is used to assign population values to grid cells. The population count grids contain estimates of the number of persons per grid cell. The grids are available in various GIS-compatible data formats and geographic extents (global, continent [Antarctica not included], and country levels). GPWv3 is produced by the Columbia University Center for International Earth Science Information...
Two major approaches address the need to predict species distributions in response to environmental changes. Correlative models estimate parameters phenomenologically by relating current distributions to environmental conditions. By contrast, mechanistic models incorporate explicit relationships between environmental conditions and organismal performance, estimated independently of current distributions. Mechanistic approaches include models that translate environmental conditions into biologically relevant metrics (e.g. potential duration of activity), models that capture environmental sensitivities of survivorship and fecundity, and models that use energetics to link environmental conditions and demography. We...
Predictive models of species distributions are typically developed with data collected along roads. Roadside sampling may provide a biased (nonrandom) sample; however, it is currently unknown whether roadside sampling limits the accuracy of predictions generated by species distribution models. We tested whether roadside sampling affects the accuracy of predictions generated by species distribution models by using a prospective sampling strategy designed specifically to address this issue. We built models from roadside data and validated model predictions at paired locations on unpaved roads and 200 m away from roads (off road), spatially and temporally independent from the data used for model building. We predicted...
We attempted a complete review of the empirical literature on effects of roads and traffic on animal abundance and distribution. We found 79 studies, with results for 131 species and 30 species groups. Overall, the number of documented negative effects of roads on animal abundance outnumbered the number of positive effects by a factor of 5; 114 responses were negative, 22 were positive, and 56 showed no effect. Amphibians and reptiles tended to show negative effects. Birds showed mainly negative or no effects, with a few positive effects for some small birds and for vultures. Small mammals generally showed either positive effects or no effect, mid-sized mammals showed either negative effects or no effect, and large...
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This study, or Pilot Analysis of Global Ecosystems (PAGE), examines forest ecosystems of the world using a large collection of spatial and temporal data. This study analyzes datasets at the global, national, and subnational levels, and draws on published and unpublished scientific studies. It develops selected indicators that describe the condition of the world's forests, where condition is defined as the current and future capacity of forests to provide the full range of goods and services that humans need and consume.
map background search result map search result map Census TIGER 2009 Map Montana 1990 Population Density 1-km grid Montana 2000 Population Density 1-km grid The Milk River Basin Project; Habitat Suitability Models for Selected Wildlife Management Species No. 86. Alberta Species At Risk Report, Alberta Sustainable Resource Development, 2004 El Salvador Population Density_ 2000 USA Population Density Global Population Density and Tree Cover Populated Areas in the Western United States Populated Areas in the Western United States U.S. block-level population density rasters for 1990, 2000, and 2010 BLM REA NGB 2011 Distance to Roads within Greater Sage-grouse PPH BLM REA NGB 2011 Population Density within Greater Sage-grouse PPH El Salvador Population Density_ 2000 Montana 2000 Population Density 1-km grid Montana 1990 Population Density 1-km grid BLM REA NGB 2011 Population Density within Greater Sage-grouse PPH BLM REA NGB 2011 Distance to Roads within Greater Sage-grouse PPH U.S. block-level population density rasters for 1990, 2000, and 2010 Populated Areas in the Western United States Populated Areas in the Western United States USA Population Density Global Population Density and Tree Cover Census TIGER 2009 Map