Factors Affecting the Occurrence of Saugers in Small, High-Elevation Rivers near the Western Edge of the Species' Natural Distribution

2005 ◽  
Vol 134 (1) ◽  
pp. 160-171 ◽  
Author(s):  
Craig J. Amadio ◽  
Wayne A. Hubert ◽  
Kevin Johnson ◽  
Dennis Oberlie ◽  
David Dufek
Keyword(s):  
High Elevation ◽  
Natural Distribution ◽  
Factors Affecting

scholarly journals The Within-Population Formation of the Upper Range Limit in a Songbird

2021 ◽  
Author(s):  
Martin Grüebler ◽  
Johann von Hirschheydt ◽  
Fränzi Korner-Nievergelt
Keyword(s):  
Environmental Gradients ◽  
Elevational Gradient ◽  
High Elevation ◽  
Range Limit ◽  
Apparent Survival ◽  
Breeding Sites ◽  
Factors Affecting ◽  
Mobile Species ◽  
Random Dispersal ◽  
High Elevations

Abstract The formation of the upper distributional range limit of species at mountain slopes is often based on environmental gradients resulting in changing demographic rates towards high elevations. However, we still lack an empiric understanding of how the interplay of demographic parameters forms the upper range limit in highly mobile species. Here, we study apparent survival and within-study area dispersal over a 700 m elevational gradient in barn swallows (Hirundo rustica) by using 15 years of capture-mark-recapture data. Annual apparent survival of adult breeding birds decreased while breeding dispersal probability of adult females, but not males increased towards the upper range limit. Individuals at high elevations dispersed to farms situated at lower elevations than would be expected by random dispersal. These results suggest higher turn-over rates of breeding individuals at high elevations, an elevational increase in immigration and thus, within-population source-sink dynamics between low and high elevations. The formation of the upper range limit therefore is based on preference for low-elevation breeding sites and immigration to high elevations. Thus, shifts of the upper range limit are not only affected by changes in the quality of high-elevation habitats but also by factors affecting the number of immigrants produced at low elevations.

Distribution of annual Trifolium species in Morocco

1993 ◽  
Vol 44 (6) ◽  
pp. 1303 ◽  
Author(s):  
PE Beale ◽  
M Bounejmate ◽  
A Lahlou ◽  
DB Marx ◽  
S Christiansen
Keyword(s):  
Environmental Factors ◽  
Seed Yield ◽  
Phosphorus Content ◽  
Climatic Factors ◽  
Natural Distribution ◽  
Factors Affecting ◽  
Determinant Factors ◽  
Number Of Species ◽  
The Relationship

An ecogeographic survey was conducted in six key agricultural zones in Morocco to study the abundance and the relationship between the natural distribution of annual Trifolium species and environmental factors. Sixteen species of annual Trifolium species were identified. Most prolific was T. scabrum and the least were T. striatum and T. bocconei. Fifty-five percent of the sites had no Trifolium and the average number of species per site was 2.2. An average seed yield of 4.8 kg ha-1 was obtained. Both soil and climatic factors affected the occurrence of Trifolium species. Rainfall, pH and phosphorus content were the most determinant factors affecting the distribution of Trifolium species in Morocco.

scholarly journals Whitebark Pine Planting Guidelines

2009 ◽  
Vol 24 (3) ◽  
pp. 163-166 ◽  
Author(s):  
Ward McCaughey ◽  
Glenda L. Scott ◽  
Kay L. Izlar
Keyword(s):  
Abiotic Factors ◽  
Survival Rates ◽  
High Elevation ◽  
Pine Plantations ◽  
Whitebark Pine ◽  
Factors Affecting ◽  
Soil Movement ◽  
New Information ◽  
Wide Range ◽  
Us Forest Service

Abstract This article incorporates new information into previous whitebark pine guidelines for planting prescriptions. Earlier 2006 guidelines were developed based on review of general literature, research studies, field observations, and standard US Forest Service survival surveys of high-elevation whitebark pine plantations. A recent study of biotic and abiotic factors affecting survival in whitebark pine plantations was conducted to determine survival rates over time and over a wide range of geographic locations. In these revised guidelines, we recommend reducing or avoiding overstory and understory competition, avoiding swales or frost pockets, providing shade and wind protection, protecting seedlings from heavy snow loads and soil movement, providing adequate growing space, avoiding sites with lodgepole or mixing with other tree species, and avoiding planting next to snags.

Factors Affecting Sockeye Salmon (Oncorhynchus nerka) Growth in Four Lakes of the Fraser River System

1974 ◽  
Vol 31 (5) ◽  
pp. 871-892 ◽  
Author(s):  
J. C. Goodlad ◽  
T. W. Gjernes ◽  
E. L. Brannon
Keyword(s):  
Population Density ◽  
Standing Crop ◽  
Sockeye Salmon ◽  
River System ◽  
Growing Season ◽  
High Elevation ◽  
Zooplankton Abundance ◽  
Fraser River ◽  
Factors Affecting ◽  
Short Growing Season

Analysis of data from four sockeye rearing lakes of the Fraser River system for periods of up to 20 yr provided information on the relation of estimated fish density (female spawners/ha), temperature, and zooplankton standing crops to growth. The lakes differed widely in all attributes. Growth was inversely related to estimated population density in three of the lakes, but wide variations in growth at low density occurred in the fourth, a cold lake at high elevation with short growing season. In this lake, and to a lesser extent in another lake with short growing season, temperature during fry emergence and early lake residence accounted for much of the recorded fluctuation in growth. Reduced zooplankton abundance was associated with high sockeye density in two of the lakes with intermediate standing crops and greatest sockeye densities, but was not recorded in a lake of low standing crop and intermediate sockeye density. Sockeye feeding was found to be highly selective in one lake, and a limited proportion of the zooplankton standing crop was utilized. It is suggested that reduction in standing crop by grazing of juvenile sockeye, and associated decrease in growth, is greatest as the large zooplankters are progressively reduced in abundance. Further reduction in standing crop and in sockeye growth was suggested to proceed at a slower rate. Competition at high population density was concluded to be the factor most responsible for reducing sockeye growth.

Factors Affecting the Distribution and Abundance of Microlaena Stipoides (Labill.) R.br. On the Northern Tablelands of New South Wales.

1994 ◽  
Vol 16 (1) ◽  
pp. 26 ◽  
Author(s):  
DB Magcale-Macandog ◽  
RDB Whalley
Keyword(s):  
Warm Season ◽  
High Elevation ◽  
Soil Disturbance ◽  
Tree Density ◽  
Perennial Grasses ◽  
Site Factors ◽  
Pasture Management ◽  
Factors Affecting ◽  
The North ◽  
Microlaena Stipoides

The distribution of Microlaena stipoides on the Northern Tablelands of NSW was examined in a survey of 101 paddocks on 33 properties. Relationships among the abundance of M. stipoides and spatial, climatic, soil and pasture management factors were determined using X2, regression and cluster analyses. Paddocks with more abundant M. stipoides were observed in the eastern and southern parts of the Tablelands where altitude (>750 m) and rainfall (>750 mm) are higher. Higher tree density was associated with more abundant M, stipoides as were native and natural compared with highly improved pastures. Frequent cultivation (regular and intermittent) was associated with absence or very low abundance of M. stipoides. On the other hand, paddocks which had not been cultivated for along time tended to have more M. stipoides than those that had been cultivated in the last five years. Total amount of superphosphate applied, type of grazing animal and grazing method were not associated with the abundance of M. stipoides. Acidic soils had more M, stipoides than soils of higher pH (up to 6.5). Combinations of site factors such as high elevation and rainfall, high tree density, minimum soil disturbance and acidic soil lead to abundant M. stipoides in pastures. Pasture communities in the north and west of the study area had a greater abundance of native warm season perennial grasses and less M. stipoides.

scholarly journals Soil characteristics of natural silver linden (Tilia tomentosa Moench) populations

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 9588-9600
Author(s):  
Salih Parlak ◽  
Erdem Tetik
Keyword(s):  
Sandy Loam ◽  
Natural Populations ◽  
Soil Characteristics ◽  
Clay Loam ◽  
Natural Distribution ◽  
Factors Affecting ◽  
Tilia Tomentosa ◽  
Shadow It ◽  
Physical And Chemical

Studies regarding the determination of the ecological characteristics of the natural distribution areas of the silver linden (Tilia tomentosa Moench) are limited. It is of great importance to select areas with similar natural cultivation characteristics in the plantations established for flower or timber production. Physiographical factors affecting these forests were explored to determine the physical and chemical characteristics of the soil. The soil samples were collected from three natural populations, and a total of 43 samples were examined in terms of aspect, elevation, declivity position, and slope. It was determined that the natural linden populations expanded between the altitudes of 0 m and 400 m and 88% of the populations were denser in aspects with shadow. It was found that 91% of the soil was in the class of “deep to very deep”, 61% showed an expansion in sandy clay loam soils, and 30% showed an expansion in sandy loam soils. Average soil pH ranged between 5.6 and 6.6. The soils were found to be salt-free and slightly limy. In terms of the organic carbon amount, the soils were classified as medium.

Habitat associations, resources, and predators of an assemblage of Brachinus (Coleoptera: Carabidae) from southeastern Arizona

1985 ◽  
Vol 63 (7) ◽  
pp. 1683-1691 ◽  
Author(s):  
Steven A. Juliano
Keyword(s):  
Ecological Factors ◽  
High Elevation ◽  
Habitat Associations ◽  
Temporary Ponds ◽  
Temporary Pond ◽  
Reproductive Phenology ◽  
Host Use ◽  
Factors Affecting ◽  
Assemblage Composition ◽  
Water Beetle

Bombardier beetles (Brachinus) at margins of ponds across gradients of elevation and pond permanence were studied to describe habitat associations and resource use and to form hypotheses concerning the ecological factors affecting these beetles. Assemblage composition differed significantly among pond types, with more permanent ponds dominated by Brachinus lateralis, high-elevation temporary ponds dominated by Brachinus mexicanus, and Brachinus javalinopsis and Brachinus lateralis codominant at a low-elevation temporary pond. Brachinus mexicanus was sometimes found at dry temporary pond sites, but none of the other species was ever found at dry sites. These species shared at least two potentially limiting resources: food for adults (carrion and arthropods) and hosts for ectoparasitoid larvae (water beetle pupae). Reproductive phenology, host use, and diets overlapped extensively. Host abundances and host-assemblage composition varied among sites and most hosts went unparasitized. Predation on adults by vertebrates appeared to be very rare. Although some predatory arthropods ate Brachinus in the laboratory, these predators were either rare or ineffective in natural situations.

scholarly journals Catchment features controlling nitrogen dynamics in running waters above the tree line (central Italian Alps)

2013 ◽  
Vol 17 (3) ◽  
pp. 989-1001 ◽  
Author(s):  
R. Balestrini ◽  
C. Arese ◽  
M. Freppaz ◽  
A. Buffagni
Keyword(s):  
Land Cover ◽  
Soil Cover ◽  
High Elevation ◽  
Nitrogen Dynamics ◽  
Running Waters ◽  
Tree Line ◽  
Italian Alps ◽  
Long Distance ◽  
Mountain Areas ◽  
Factors Affecting

Abstract. The study of nitrogen cycling in mountain areas has a long tradition, as it was applied to better understand and describe ecosystem functioning, as well as to quantify long-distance effects of human activities on remote environments. Nonetheless, very few studies, especially in Europe, have considered catchment features controlling nitrogen dynamics above the tree line with focus on running waters. In this study, relationships between some water chemistry descriptors – including nitrogen species and dissolved organic carbon (DOC) – and catchment characteristics were evaluated for a range of sites located above the tree line (1950–2650 m a.s.l.) at Val Masino, in the central Italian Alps. Land cover categories as well as elevation and slope were assessed at each site. Water samples were collected during the 2007 and 2008 snow free periods, with a nearly monthly frequency. In contrast to dissolved organic nitrogen, nitrate concentrations in running waters showed a spatial pattern strictly connected to the fractional extension of tundra and talus in each basin. Exponential models significantly described the relationships between maximum NO3 and the fraction of vegetated soil cover (negative relation) and talus (positive relation), explaining almost 90% of nitrate variation in running waters. Similarly to nitrate but with an opposite behavior, DOC was positively correlated with vegetated soil cover and negatively correlated with talus. Therefore, land cover can be considered one of the most important factors affecting water quality in high-elevation catchments with contrasting effects on N and C pools.

Climatic factors affecting radial growth of Betula ermanii and Betula platypylla in Kamchatka

2010 ◽  
Vol 40 (2) ◽  
pp. 273-285 ◽  
Author(s):  
Jiri Doležal ◽  
Hiroaki Ishii ◽  
Tomáš Kyncl ◽  
Koichi Takahashi ◽  
Valentina P. Vetrova ◽  
...  
Keyword(s):  
Radial Growth ◽  
Climatic Factors ◽  
Ring Width ◽  
Kamchatka Peninsula ◽  
High Elevation ◽  
Winter Precipitation ◽  
Growth Responses ◽  
Factors Affecting ◽  
Betula Ermanii ◽  
The Pacific

Radial growth responses to climate were studied in two species of birch broadly distributed across Kamchatka Peninsula. Wood cores were obtained in different locations and environments, from upper to lower treelines, and from wet maritime sites at the Pacific to the subcontinental interior of the peninsula. Response functions were calculated using the four longest meteorological records (1920s–2000) in Kamchatka. In Betula ermanii Cham., the dominant species in mountains and maritime woodlands, ring width in high-elevation (500–600 m) trees increased with warm and less rainy June and July and decreased with rainy/snowy cool weather during the prior September and October. Radial growth in B. ermanii low-elevation trees increased with higher winter precipitation, suggesting that water from melting snow prevents water stress and possibly desiccation in low-elevation trees. In Betula platyphylla Sukaczev, a common taiga species in interior Kamchatka, low summer temperatures limited growth at its upper distributional limit (300–350 m) and in cool, wet sites dominated by Picea ajanensis Lindl. et Gord. On drier sites dominated by Larix cajanderii Mayr., growth was limited by warm April and dry June weather. Variable responses along elevation–continentality gradients reinforce the necessity of a site-dependent differentiation for the assessment of impacts of climate change on species performance and geographic range shifts.

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