نتایج جستجو برای: visitation

تعداد نتایج: 2007  

Journal: :Journal of environmental management 2003
Hayley Hesseln John B Loomis Armando González-Cabán Susan Alexander

We use a travel cost model to test the effects of wild and prescribed fire on visitation by hikers and mountain bikers in New Mexico. Our results indicate that net benefits for mountain bikers is $150 per trip and that they take an average of 6.2 trips per year. Hikers take 2.8 trips per year with individual net benefits per trip of $130. Both hikers' and mountain bikers' demand functions react...

2010
Lin Zhu Anru Lou

Aims Rhodiola dumulosa is a perennial herb growing in a naturally fragmented habitat of high-mountain rocks. This research aims to (i) investigate the mating system characteristics and pollination biology of R. dumulosa, (ii) study the effects of ecological factors on the mating system and pollination biology of R. dumulosa and (iii) assess the relationship between its pollination and mating sy...

2014
Mialy Razanajatovo Christine Föhr Markus Fischer Daniel Prati Mark van Kleunen

Many animal-pollinated plant species have been introduced to non-native regions without their usual pollinators. Nevertheless, some of these alien species managed to establish reproducing naturalized populations, which might negatively affect native plants. Recent studies have shown that many naturalized alien species can readily attract native pollinators. However, it is not known whether alie...

Journal: :The New phytologist 2008
Mélanie Glaettli Spencer C H Barrett

In animal-pollinated plants with unisexual flowers, sexual dimorphism in floral traits may be the consequence of pollinator-mediated selection. Experimental investigations of the effects of variation in flower size and floral display on pollinator visitation can provide insights into the evolution of floral dimorphism in dioecious plants. Here, we investigated pollinator responses to experiment...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1999
D W Schemske H D Bradshaw

A paradigm of evolutionary biology is that adaptation and reproductive isolation are caused by a nearly infinite number of mutations of individually small effect. Here, we test this hypothesis by investigating the genetic basis of pollinator discrimination in two closely related species of monkeyflowers that differ in their major pollinators. This system provides a unique opportunity to investi...

2011
Josef Navrátil Kamil Pícha Josef Rajchard Jana Navrátilová

Th e goal of this paper is the assessment of the impact of personal experience on visitors' perceptions of the environments of selected tourist attractions. Th e cognitive paradigm of environmental perception research was chosen and the Mehrabian-Russell general measure of information rate was used. Students from the University of South Bohemia from three diff erent study programmes (faculties)...

Journal: :Ecology letters 2008
Taylor H Ricketts James Regetz Ingolf Steffan-Dewenter Saul A Cunningham Claire Kremen Anne Bogdanski Barbara Gemmill-Herren Sarah S Greenleaf Alexandra M Klein Margaret M Mayfield Lora A Morandin Alfred Ochieng' Simon G Potts Blande F Viana

Pollination by bees and other animals increases the size, quality, or stability of harvests for 70% of leading global crops. Because native species pollinate many of these crops effectively, conserving habitats for wild pollinators within agricultural landscapes can help maintain pollination services. Using hierarchical Bayesian techniques, we synthesize the results of 23 studies - representing...

2011
Sarah Gehring

This report explores the differences in farm and farmer attributes, marketing and management practices, and economic performance among agritourism farms in Missouri receiving different numbers of visitors 1. This is the second report derived from the Missouri Agritourism Survey, a study conducted in 2009 by the Missouri Department of Agriculture and the University of Missouri Department of Park...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2014
Clare E Aslan Erika S Zavaleta Bernie Tershy Don Croll Robert H Robichaux

Native plant species that have lost their mutualist partners may require non-native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipulations of pollen transfer) to examine relation...

ژورنال: کومش 2019
Akbari , Reihane , Bagheri Moghaddam , Ahmad , Karimi Moonaghi , Hossein , Mazloum , Seyedreza,

Introduction: Visiting patient in intensive care unit (ICUs) is one of the major challenges in healthcare. The belief that visiting will increase the anxiety and create destructive effects on the patient's physiological indices, has led to a serious visiting restriction for patients and their. Therefore, the present study aimed to investigate the effect of flexible (planned) visiting policy on ...

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