scholarly journals Whitebark Pine Recruitment in Sierra Nevada Driven by Range Position and Disturbance History

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 455
Author(s):  
Michèle R. Slaton ◽  
Martin MacKenzie ◽  
Tanya Kohler ◽  
Carlos M. Ramirez
Keyword(s):  
Sierra Nevada ◽  
Seedling Recruitment ◽  
Canopy Cover ◽  
Whitebark Pine ◽  
Disturbance History ◽  
Seedling Density ◽  
Factors Affecting ◽  
Range Edge ◽  
Biogeographic Region

Effective restoration of whitebark pine populations will require a solid understanding of factors affecting seedling recruitment success, which may vary by site and biogeographic region. We examined the relationship between whitebark pine seedling recruitment, disturbance history, and range position in three independent studies in the southern Sierra Nevada, California (CA), USA. In 66 plots broadly distributed across watersheds, we found that whitebark pine seedling density and proportion were greatest at upper elevations, and where canopy cover of whitebark pine was higher (density ranged 0–383 seedlings/ha; x ¯ = 4, σX = 1). Seedling density and proportion were also greater in plots that had recently experienced loss of canopy cover from insects, avalanche, windthrow, or other disturbance effects. In a second study conducted in popular recreational areas, including campgrounds and trailheads, the response of whitebark pine recruitment to disturbance was strongly dependent on the relative position of stands within the range, or proximity to other forest types. Both studies indicated that low to moderate levels of disturbance enhanced whitebark pine recruitment, especially at its range edge, a finding consistent with the early seral status of whitebark observed in previous studies conducted elsewhere in North America. In our third study, a case study at the June Mt. Ski Area, we demonstrate the potential for a downward shift in the whitebark-lodgepole pine ecotone as a result of insect-caused disturbance.

Factors Affecting The Sustainability Of The Asphalt Roads: A Case Study Of Irbid Inner Ring Road, Jordan

2011 ◽  
Vol 1 (5) ◽  
pp. 93-94
Author(s):  
Eng. Nasr Ahmad Eng. Nasr Ahmad ◽  
◽  
Dr. Mihai Iliescu
Keyword(s):  
Factors Affecting ◽  
Ring Road

Factors Affecting Financial Literacy of Vietnamese Adults: A Case Study for Hanoi and Nghe An

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Tue Nguyen Dang
Keyword(s):  
Higher Education ◽  
Multiple Regression ◽  
Financial Literacy ◽  
Urban Areas ◽  
Logistic Models ◽  
Factors Affecting ◽  
Financial Behaviors ◽  
Financial Decisions ◽  
Literacy Level

This research examines the factors affecting the financial literacy of Vietnamese adults. Using a sample of 266 observations of adults in 2 big cities in Vietnam (Hanoi and Vinh in Nghe An Province), the author evaluates the literacy level of adults in these urban areas. The financial literacy of the interviewed people is low. The multiple regression results show that lower financial literacy levels associate with higher age and married status and higher financial literacy levels associate with higher education, more family members, the person making financial decisions and the person attending a useful financial course. This research also explores the association between financial literacy and financial behaviors of individuals employing logistic models. It is found that higher financial literacy associates with less probability of overspending and higher probability of saving money and careful spending. Higher financial literacy is also found to associate with higher probability of opening a savings account and making various investments. 

scholarly journals Factors affecting presence and relative abundance of the Endangered volcano rabbit Romerolagus diazi, a habitat specialist

Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Felipe Osuna ◽  
Roger Guevara ◽  
Enrique Martínez-Meyer ◽  
Raúl Alcalá ◽  
Alejandro Espinosa de los Monteros
Keyword(s):  
Sierra Nevada ◽  
Relative Abundance ◽  
Linear Models ◽  
Cattle Grazing ◽  
Patch Occupancy ◽  
Factors Affecting ◽  
Rock Cover ◽  
Volcanic Fields ◽  
Mountain Grasslands ◽  
Insight Into

Abstract Habitat specialists are particularly vulnerable to extinction when habitat conditions are altered. Information on the habitat use of such species is thus important because it provides insight into factors that influence distribution and abundance, which is crucial for conservation. Here, we aimed to identify factors that influence the patterns of presence and abundance of the Endangered volcano rabbit Romerolagus diazi, a rare leporid with a patchy distribution. Through exhaustive sampling of its range in the Sierra Chichinautzin and Sierra Nevada volcanic fields, Mexico, and using generalized linear models, we found that the probability of patch occupancy was higher where bunchgrass cover exceeded 75%, rock cover exceeded 5%, no cattle grazing was observed and human settlements were at least 7 km away. Patches with greater relative abundance were those with similar characteristics, but located at elevations > 3,600 m, and with rock cover < 15%. Cattle grazing was identified as a major threat to local populations of the volcano rabbit, particularly in the Sierra Chichinautzin. Because of the significance of bunchgrasses for this species, the protection of the mountain grasslands is required in both volcanic fields.

Determinants of water purchases by pistachio producers in an informal groundwater market: a case study from Iran

Water Policy ◽  
2015 ◽  
Vol 18 (3) ◽  
pp. 599-618 ◽  
Author(s):  
Tinoush Jamali Jaghdani ◽  
Bernhard Brümmer
Keyword(s):  
Water Allocation ◽  
Field Survey ◽  
Water Markets ◽  
Factors Affecting ◽  
Marginal Value ◽  
Socioeconomic Characteristics ◽  
Participation Decision ◽  
Eastern Iran ◽  
Scarce Water

Market-based water allocation systems have the potential to ensure that scarce water will flow to the user who earns the highest marginal value from that water. However, the number of recorded instances where water supply problems are solved by market-based systems remains limited. This study attempts to identify the decisive factors that motivate farmers’ participation in informal spot water markets in the Rafsanjan aquifer in south-eastern Iran. A two-stage random sampling was carried out in a field survey from November 2008 to February 2009. A logit model is used to test the factors affecting farmers’ decisions to buy groundwater from neighbours who share the same pump. The results show that the technological variables contribute substantially to the participation decision. For example, a decrease in water quality, an increase in the age of the garden, and an increase in the size of the water quota reduce the probability of participation. In contrast, more scattered plots, a higher water flow level from pumping, and a deeper well increase the probability of participation in water markets. Finally, the results suggest that in this area, the participation in water markets is motivated more by profit increasing factors than by farmer socioeconomic characteristics.

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