نتایج جستجو برای: habitat conditions

تعداد نتایج: 894764  

2015
Yiping Yang

Introduction Preventive vaccination against infectious diseases is considered one of the most successful health measures of all time. Therapeutic vaccination against established diseases such as persistent infections and cancer has proven much more challenging, because the vaccine intervention must combat an immune system that has been restrained by tolerizing or polarizing mechanisms that sust...

2011
N. C. Apreutesei

An optimal control problem is studied for a predator-prey system of PDE, with a logistic growth rate of the prey and a general functional response of the predator. The control function has two components. The purpose is to maximize a mean density of the two species in their habitat. The existence of the optimal solution is analyzed and some necessary optimality conditions are established. The f...

2015
Megan M. Friggens Deborah M. Finch Danilo Russo

Future expected changes in climate and human activity threaten many riparian habitats, particularly in the southwestern U.S. Using Maximum Entropy (MaxEnt3.3.3) modeling, we characterized habitat relationships and generated spatial predictions of habitat suitability for the Lucy's warbler (Oreothlypis luciae), the Southwestern willow flycatcher (Empidonax traillii extimus) and the Western yello...

2006
Fritz Schiemer

Large rivers and their riparian zones are hot spots of biodiversity (WARD et al. 1999). Fluvial geomorphic processes provide the habitat diversity and the specific habitat conditions for characteristic species assemblages and result in high levels of habitat diversity, local species richness (α-diversity), and between-habitat differences (beta-diversity) and consequently, overall species richne...

Journal: :Ecological applications : a publication of the Ecological Society of America 2015
Sebastián Martinuzzi John C Withey Anna M Pidgeon Andrew J Plantinga Alexa J McKerrow Steven G Williams David P Helmers Volker C Radeloff

Land-use change is a major cause of wildlife habitat loss. Understanding how changes in land-use policies and economic factors can impact future trends in land use and wildlife habitat loss is therefore critical for conservation efforts. Our goal here was to evaluate the consequences of future land-use changes under different conservation policies and crop market conditions on habitat loss for ...

2005
LISA A. SCHULTE ANNA M. PIDGEON DAVID J. MLADENOFF

Evaluating bird population trends requires baseline data. In North America the earliest population data available are those from the late 1960s. Forest conditions in the northern Great Lake states (U.S.A.), however, have undergone succession since the region was originally cut over around the turn of the twentieth century, and it is expected that bird populations have undergone concomitant chan...

Journal: :Journal of vector borne diseases 2011
Barnali Manna Gautam Aditya Samir Banerjee

OBJECTIVE The ability of the native larvivorous fish Aplocheilus panchax (Hamilton, 1822) (Cyprinodontiformes: Aplocheilidae) as predator of mosquito larvae was assessed under laboratory conditions using multiple prey and habitat conditions. METHODS The consumption of larvae of the mosquito Culex quinquefasciatus Say 1823 (Diptera: Culicidae) by A. panchax was evaluated in the presence of tub...

K. Sabetraftar, Sh. Shafii

The vegetation covering of a region has a direct correlation with climate. So if data is available for vegetation cover, the second variable (climate) can be easily predicted and in reverse. The dominant species in a region are indication of its climatic conditions and vice versa. Accordingly, this is of significance in the science of historical botany. Fortunately, from the first millennium A...

2004
James G. Dickson

wood ducks that winter extensively in southern bottoms, nest throughout much of forested North America. And probably more importantly than use by individual animals, broad-scale landscape habitat conditions affect wildlife community composition and population function of species. For example, very small pockets of forest habitat may serve as sinks for forest interior birds, where mortality exce...

This study was accomplished with the aim of investigating the effects of tree decline and slope aspect on leaf morphological traits and determining the indicator morphological traits that indicate the leaf diversity of Persian oak trees in relation to habitat conditions and environmental stresses in Mellah Siah forests of Ilam. Two forest habitats were selected on the northern and southern slop...

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