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Registros recuperados: 49
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A seasonally varying biotope at Signy Island, Antarctic: implications for meiofaunal structure OMA
Vanhove, S.; Beghyn, M.; Van Gansbeke, D.; Bullough, L.W.; Vincx, M..
Under the typical high-latitude conditions of temperature, productivity and settlement of chlorophyll and phaeophytin to the sediment, many benthic organisms in the Antarctic show strong seasonal variation. Although meiofauna comprise an important component of the southpolar benthic ecosystem, our knowledge of them is limited. The metazoan meiofauna and the surrounding sediments were studied fortnightly for 18 mo in a shallow bay at Signy Island (Factory Cove, South Orkneys, Antarctica) to test whether and how the temporal variability of the environment influenced meiobenthos dynamics. By examination of the distribution of the abundance and biomass of the total community, the density of higher taxonomic groups, and of individual dominant nematode genera...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Benthos; Biomass; Population density; Seasonal variations; Sediment analysis; Trophic relationships; Copepoda [copepods]; Nematoda [Nematodes]; Ostracoda.
Ano: 2000 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6138
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Calidad física y fisiológica en la semilla e industrial en el grano de Amaranthus hypochondriacus en la fertilización y densidad de población. Colegio de Postgraduados
Ramírez Vázquez, Ma. de la Luz.
La calidad de la semilla es una característica de fundamental jerarquía en la producción de cualquier cultivo: dado que hay una amplia influencia en la fertilización y densidad de población sobre el rendimiento, principalmente y respecto a la necesidad que existe en la actualidad sobre el manejo de la calidad de semilla y grano por los productores en nuevas variedades y de conocer cómo está puede ser modificada mediante prácticas agronómicas definidas que permitan mejorar el proceso industrial (reventado) e identificar la respuesta de estas variedades a la aportación de fertilización y densidades de población, así como encontrar las variables que permitan obtener un mayor incremento en el rendimiento y calidad de semilla y grano sé platearon los siguientes...
Palavras-chave: Amaranthus hypochondriacus L.; Fertilización; Densidad de población; Revancha; Gabriela; DGETA; Population density; Fertilization; Doctorado; Producción de Semillas.
Ano: 2010 URL: http://hdl.handle.net/10521/283
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Contribución al estudio de los quetognatos alrededor de las Islas Galápagos OceanDocs
Naranjo, Ch..
El presente estudio tiene como labor fundamental conocer la distribución cuantitativa de las especies de quetognatos y su relación con factores como la temperatura, salinidad y establecer áreas de alta productividad en las Islas Galápagos con la presencia de especies bio-indicadoras de afloramiento.
Tipo: Journal Contribution Palavras-chave: Indicator species; Upwelling; Zooplankton; Marine invertebrates; Population density; Environmental factors; Zooplankton; Environmental factors; Indicator species; Population density; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_2594; Http://aims.fao.org/aos/agrovoc/c_35790; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 2000 URL: http://hdl.handle.net/1834/2223
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Controle biologico do nematoide-das-galhas com bacteria Pasteuria penetrans. Infoteca-e
SHARMA, R. D.; VIVALDI, L. J..
bitstream/CPAC-2009/24830/1/bolpd_80.pdf
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) Palavras-chave: Densidade populacional; Plant diseases; Plant galls.; Bactéria; Controle Biológico; Doença de Planta; Galha; Glycine Max; Nematóide; Meloidogyne Javanica; Soja.; Nematoda; Pasteuria penetrans; Biological control; Population density; Soybeans..
Ano: 2003 URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/567788
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Crecimiento y rendimiento de haba (Vicia faba L.) en ambientes contrastantes. Colegio de Postgraduados
Pichardo Riego, Juan Carlos.
En México el cultivo de haba es de gran importancia social y económica principalmente en la región de los “Valles altos”, que aportan cerca del 98% a la producción nacional. Sin embargo debido a los bajos rendimientos de esta leguminosa se requiere un manejo del cultivo más apropiado en función de la diversidad de ambientes en que se desarrolla, incluyendo la búsqueda de cultivares de máximo rendimiento de grano seco para cada localidad. El objetivo del estudio fue determinar el comportamiento de distintos cultivares de haba en diferentes ambientes e identificar el más productivo de acuerdo a la región de estudio y a éste, aplicarle la mejor combinación de fertilización nitrogenada, fosfatada y densidad de población (DP). El estudio se realizó bajo...
Palavras-chave: Cultivar; Nitrógeno; Fósforo; Densidad de población; Rendimiento; Estabilidad de rendimiento; Máxima eficiencia biológica; Máxima eficiencia económica; Tratamiento óptimo económico; Cultivar; Nitrogen; Phosphorus; Population density; Yield; Yield stability; Maximum biological efficiency; Maximum economical efficiency; Optimum economic treatment; Doctorado; Botánica.
Ano: 2010 URL: http://hdl.handle.net/10521/157
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Crecimiento y rendimiento de haba (Vicia faba L.) en ambientes contrastantes. Colegio de Postgraduados
Pichardo Riego, Juan Carlos.
En México el cultivo de haba es de gran importancia social y económica principalmente en la región de los “Valles altos”, que aportan cerca del 98% a la producción nacional. Sin embargo debido a los bajos rendimientos de esta leguminosa se requiere un manejo del cultivo más apropiado en función de la diversidad de ambientes en que se desarrolla, incluyendo la búsqueda de cultivares de máximo rendimiento de grano seco para cada localidad. El objetivo del estudio fue determinar el comportamiento de distintos cultivares de haba en diferentes ambientes e identificar el más productivo de acuerdo a la región de estudio y a éste, aplicarle la mejor combinación de fertilización nitrogenada, fosfatada y densidad de población (DP). El estudio se realizó bajo...
Palavras-chave: Cultivar; Nitrógeno; Fósforo; Densidad de población; Rendimiento; Estabilidad de rendimiento; Máxima eficiencia biológica; Máxima eficiencia económica; Tratamiento óptimo económico; Cultivar; Nitrogen; Phosphorus; Population density; Yield; Yield stability; Maximum biological efficiency; Maximum economical efficiency; Optimum economic treatment; Doctorado; Botánica.
Ano: 2010 URL: http://hdl.handle.net/10521/157
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Demand for Urban Forests and Economic Welfare: Evidence from the Southeastern U.S. Cities AgEcon
Zhu, Pengyu; Zhang, Yaoqi.
This study examines the relationship between urban forests and household income and population density in the 149 cities with populations over 40,000 in nine southeastern states. Our empirical results show that urban forest percentage across the cities has characteristics of the environmental Kuznets curve. We find that household income around $39,000 is a threshold that changes the relationship between income and urban forest coverage from negative to positive, whereas the impact of population density on urban forests is just the opposite, from positive to negative when population density is around 180 persons per square kilometer.
Tipo: Journal Article Palavras-chave: Environmental Kuznets curve; Environmental quality; Income; Land use; Population density; Tree canopy; Community/Rural/Urban Development; Environmental Economics and Policy; Land Economics/Use; C31; Q23; Q56; Q57; R14.
Ano: 2006 URL: http://purl.umn.edu/43758
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Desenvolvimento econômico e Desmatamento na Amazônia Legal: Uma Análise Econométrica AgEcon
Gomes, Sergio Castro; Braga, Marcelo Jose.
O objetivo deste trabalho é testar empiricamente a hipótese ambiental de Kuznets aplicada ao relacionamento entre a taxa de desmatamento e a renda per capita nos estados da Amazônia Legal, além analisar o comportamento da taxa de desmatamento e da dinâmica populacional no período de 1990-2004. O teste econométrico utilizado para avaliar a hipótese ambiental de Kuznets é baseado na estimação de dois modelos específicos de regressão, o primeiro representa uma função quadrática e o segundo uma função cúbica, em que a taxa de desmatamento é a variável explicada, e a renda per capita, a densidade demográfica e o ano são as explicativas. Na estimação dos parâmetros utilizou-se a modelagem de dados em painel para efeitos aleatórios. Os resultados mostram que para...
Tipo: Conference Paper or Presentation Palavras-chave: Desmatamento; Renda per capita; Dados de painel; Densidade demográfica; Deforestation; Per capita income; Environmental degradation; Population density; Resource /Energy Economics and Policy.
Ano: 2008 URL: http://purl.umn.edu/103095
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Development domains for Ethiopia: capturing the geographical context of smallholder development options AgEcon
Chamberlin, Jordan; Pender, John L.; Yu, Bingxin.
The choices that smallholder farmers are able to make are strongly conditioned by the geographic conditions in which they live. The importance of this fact for rural development strategy is not lost on policy makers. For example, the government of Ethiopia frequently frames policy discussions by broadly different geographical conditions of moisture availability, recognizing moisture reliable, drought prone and pastoralist areas. These conditions are seen as important criteria for determining the nature, extent and priority of development interventions for different parts of the country. There is considerable evidence, however, that other geographical factors also have important implications for rural development options. This paper uses agroecology, access...
Tipo: Report Palavras-chave: Smallholders; Small farmers; Geographic conditions; Rural development strategies; Development policy; Agro-ecology; Market access; Livelihoods; Population density; International Development.
Ano: 2006 URL: http://purl.umn.edu/55410
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Diagnóstico del recurso ostión del sur OceanDocs
Cornejo, S.; Daza, E.; Guzmán, L..
El presente informe da cuenta de los resultados de las actividades realizadas para evaluar el estado de los bancos de ostión del sur (Chlamys vitrea), en sectores selectos de la región de Magallanes y Antártica Chilena (XII Región). Se incorporan también propuestas de administración y medidas para la recuperación de las poblaciones del recurso. Se presenta la ubicación geográfica de los bancos identificados en cada fiordo y la superficie ocupada por ellos, además de las estructuras de tamaño, tallas medias, fracción de ejemplares sobre la talla mínima legal, relación longitud peso, pesos medios, estimaciones de densidad y abundancia, además de las estimaciones de las capturas totales permisibles (CTPs).
Tipo: Report Palavras-chave: Marine molluscs; Resource management; Population characteristics; Population density; Abundance; Population structure; Population structure; Resource management; Population density; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_6524; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 2005 URL: http://hdl.handle.net/1834/1755
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Diagnóstico para la administración y conservación del recurso caracol Trophon en Bahía Gente Grande, XII Región OceanDocs
González, J.; Daza, E.; Vargas, C.; Cortes, C.; Miranda, H..
El presente informe da cuenta de los resultados de las actividades realizadas para evaluar el estado actual del recurso caracol trophon (Trophon geversianus), en Bahía Gente Grande, en la XII Región. Se presenta la ubicación geográfica y superficie de los bancos identificados de Trophon y Chorito (Mytilus chilensis), las estimaciones de densidad y abundancia, su estructura de tamaños, y se incorporan los resultados del estado del recurso en el área de estudio, y se realizan consideraciones para una propuesta de administración de las poblaciones de caracol trophon.
Tipo: Report Palavras-chave: Marine molluscs; Abundance; Population density; Geographical distribution; Resource management; Geographical distribution; Population density; Resource management; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_6112; Http://aims.fao.org/aos/agrovoc/c_6524.
Ano: 2007 URL: http://hdl.handle.net/1834/1852
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Distribución, áreas de concentración y estructura de la población del bacalao austral (Salilota australis, Gunther 1887)del Atlántico Sudoccidental OceanDocs
Perez Comas, J.A..
The "bacalao austral" is a typical fish from the cold water of the Southwest Atlantic and the Southeastern Pacific oceans, whose fishery has not yet developed. In this work, the structure of the concentration areas of summer and winter distribution and other biological items were analyzed, basing on data provening from R/V"Walther Herwig" and R/V"Shinkai Maru", which operated in these waters during 1978/79/. The trophic vertical migrations are common in this species.
Tipo: Journal Contribution Palavras-chave: Geographical distribution; Size distribution; Sexual maturity; Feeding; Food chains; Length-weight relationships; Population density; Ecological distribution; Vertical migrations; Cod fisheries; Geographical distribution; Feeding; Food chains; Sexual maturity; Population density; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_2838; Http://aims.fao.org/aos/agrovoc/c_3014; Http://aims.fao.org/aos/agrovoc/c_7016; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 1980 URL: http://hdl.handle.net/1834/2060
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Distribución de la densidad fitoplanctónica en una estación fija costera. La Libertad (Ecuador), durante 1989-1993 OceanDocs
Torres, G..
El presente trabajo pretende dar a conocer los resultados de la distribución estacional cuantitativa del fitoplancton (diatomeas y dinoflagelados), y su relación con masas de agua, dadas por temperatura y salinidad, desde 1989 hasta 1993 en una estación fija costera La Libertad, período en el cual se presentó un evento "El Niño" 1991-1992.
Tipo: Journal Contribution Palavras-chave: Phytoplankton; Seasonal distribution; Water temperature; Oceanographic stations; Fixed stations; Biomass; Population density; Biomass; Phytoplankton; Water temperature; Population density; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_16063; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 1996 URL: http://hdl.handle.net/1834/2198
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Distribución del plancton a mesoescala en un área de reproducción de la anchoíta en la plataforma bonaerense OceanDocs
Akselman, R.; Carreto, J.I.; Ramirez, F.C..
In order to determine the distribution patterns of phytoplanktonic and zooplanktonic species that constitute the main food of the argentine anchovy (Engraulis anchoita), a study was made within a coastal spawning area on meso-scaled space (approximately 7 miles between stations). It was observed the predominacne of the copepod Oithona helgolandica and copepodites stages of other small-sized species, thus inferring the preponderance of nauplii stages which constitute the main food of early anchovy larvae. A high spatial heterogeneity was found in the distrtibution of both phytoplanktonic and zooplanktonic communities. Phytoplankton showed a patchiness distribution both in horizontal and vertical directions. Diatoms, dinoflagellates and coccolithophoirids...
Tipo: Journal Contribution Palavras-chave: Phytoplankton; Zooplankton; Trophic relationships; Population density; Horizontal distribution; Species diversity; Phytoplankton; Zooplankton; Species diversity; Population density; Http://aims.fao.org/aos/agrovoc/c_13344; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_33954; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 1986 URL: http://hdl.handle.net/1834/2034
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Distribución estacional y estructura poblacional del bacalao austral (Pisces, Moridae, Salilota australis) en la zona económica exclusiva argentina entre los 45°S y 56°S durante 1992 y 1993 OceanDocs
Cassia, M.C.; Hansen, J.E..
The Patagonian cod (Salilota australis) inhabits the SW Atlantic from 38°S up to 55°S, as well as the Pacific Ocean from 40°S up to 57°S. The annual catches of this species by both the Argentine fleet and those operating around the Malvinas Islands have significantly increased during the decade 1990-2000, peaking to 16,556 t in 1996. After this, a marked decrease in landings was noticed, and during 2003 the catch was 7,924 t. Seasonal distribution, concentration grounds, and population structure of the Patagonian cod from the Argentine Sea are described, and the mean densities of the species are seasonally related to latitude, temperature and depth, on the basis of data from surveys carried out by the INIDEP research vessels in 1992 and 1993. Highest mean...
Tipo: Journal Contribution Palavras-chave: Gadoid fisheries; Seasonal distribution; Population density; Population structure; Biomass; Population structure; Biomass; Population density; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 2005 URL: http://hdl.handle.net/1834/1561
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Distribución y abundancia de los recursos demersales en la plataforma continental del Ecuador durante junio de 1995 OceanDocs
Revelo, W..
The demersal phase (from june 24th to 09th, 1995) of cruise T95/06/02 DO, covered an area of 23833,6 km2 between 01° 04'1”N - 79° 59'6”O and 03° 22'7”S - 80° 48'0”O, of the Ecuadorian Continental Plataform, the deph range from 13 to 111 meters. 161 species were recorded, divided into 106 oseum fish species, five sharks, nine ray, 37 crustaceans, three molluscan and one holothurid (sea cucumber). Total biomass was estimated as 91685, 5 t, with 68,72% of this biomass distributed between 02° 15'1”S - 03°22'7”S, opposite to Guayaquil Gulf. The most abundant species were: Gallineta (Prionotus stephanophrys) (37283,7 t), Barriga juma (Larimus spp) (16146,2 t), Perela (Paralabrax spp) (14053,4 t), Palometa (Peprilus medius)(9865,3 t) and Cabezudo (Caulolatilus...
Tipo: Journal Contribution Palavras-chave: Demersal fisheries; Biomass; Geographical distribution; Population density; Demersal fisheries; Biomass; Geographical distribution; Population density; Http://aims.fao.org/aos/agrovoc/c_2173; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_6112.
Ano: 1995 URL: http://hdl.handle.net/1834/3029
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Early postlarval fish in the hyperbenthos of the Dutch Delta (south-west Netherlands) OMA
Beyst, B.; Mees, J.; Cattrijsse, A..
Early (post)larval fish constitute a significant part of the temporary hyperbenthos, i.e. of the fauna living in the lower reaches of the water column close to the substratum. Information on the densities and spatial and temporal variations of these stages, as well as on their lengths at the moment of occurrence, can be an important contribution to the knowledge of their dispersion, migrations and to the identification of possible bottlenecks in their recruitment. Therefore the hyperbenthos of the Voordelta, a shallow coastal zone in front of the Dutch Delta, as well as that of the subtidal channels and the intertidal brackish marsh creeks of the Westerschelde Estuary, was sampled monthly during one year by means of a sledge and a stow net. A total of 37...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Community composition; Deltas; Dominant species; Ecological distribution; Estuaries; Intertidal environment; Juveniles; Marine fish; Nursery grounds; Pleuronectes; Population density; Salt marshes; Sprattus sprattus; Wetlands; Zoobenthos; Clupea harengus; Dicentrarchus labrax [Bass]; Solea solea [Sole].
Ano: 1999 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3979
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Earthworm communities in organic and conventional coffee cultivation PAB
Bartz,Marie Luise Carolina; Brown,George Gardner; Pasini,Amarildo; Fernandes,Juliana de Oliveira; Curmi,Pierre; Dorioz,Julie; Ralisch,Ricardo.
The objective of this work was to evaluate the effect of organic and conventional coffee crops on biomass, population density and diversity of earthworms, in Lerroville, district of Londrina County, Paraná state, Brazil. Earthworm communities were sampled in three areas with organic coffee cultivation (CO1, CO2 and CO3), two with conventional coffee (CC1 and CC2), and a native forest fragment (MT). The soil of the areas CO1, CC1, and MT was classified as Nitossolo Vermelho (Rhodic Kandiudox), while CO2, CO3, and CC2 were on Latossolo Vermelho (Rhodic Hapludox). Eight samples were taken in each area on two occasions, winter and summer, using the Tropical Soil Biology and Fertility (TSBF) method in the 0-20 cm soil layer. The earthworms were handsorted and...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Biomass; Conventional cultivation; Diversity; Oligochaeta; Organic cultivation; Population density.
Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000800019
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Ecological factors affecting the fruiting success of a Tibouchina trichopoda (DC.) Baill. (Melastomataceae) flower Acta Botanica
Maia,Fabiano Rodrigo da; Malucelli,Tiago Simões; Varassin,Isabela Galarda.
The abundance and distribution of resources for pollinators modulate the reproduction of plants. This study attempted to determine whether and how the fruiting success of Tibouchina trichopoda flowers varies due to plant size, number of flowers produced, distance between individuals and cardinal orientation of the flowers. From July 2009 to February 2010, we conducted monthly evaluations of 21 plants in an area of regenerating forest within the Atlantic Forest biome, located near the municipality of Antonina, in southern Brazil. Floral density was monitored weekly. During the study period, the species bloomed twice: once during the cool, dry season, showing an extended flowering period with scattered flowering individuals; and once during the hot, rainy...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Resource allocation; Atlantic Rainforest; Plant-pollinator interactions; Population density; Floral longevity.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000100014
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Effects of Roads on Animal Abundance: an Empirical Review and Synthesis Ecology and Society
Fahrig, Lenore; Carleton University, Geomatics and Landscape Ecology Laboratory, Department of Biology; lfahrig@ccs.carleton.ca; Rytwinski, Trina; Carleton University, Geomatics and Landscape Ecology Laboratory, Department of Biology; trytwins@connect.carleton.ca.
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 mammals showed predominantly negative...
Tipo: Peer-Reviewed Synthesis Palavras-chave: Environmental impact; Landscape connectivity; Mortality; Population density; Road network; Road density; Road effect zone; Road mitigation; Species distribution; Species richness; Traffic density; Traffic volume.
Ano: 2009
Registros recuperados: 49
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