نتایج جستجو برای: native plants

تعداد نتایج: 293970  

2016
Kim Meijer Menno Schilthuizen Leo Beukeboom Christian Smit

A suggested mechanism for the success of introduced non-native species is the enemy release hypothesis (ERH). Many studies have tested the predictions of the ERH using the community approach (native and non-native species studied in the same habitat) or the biogeographical approach (species studied in their native and non-native range), but results are highly variable, possibly due to large var...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده ادبیات و زبانهای خارجی 1392

abstract i the purpose of this study was to launch a thorough investigation concerning the possibility of differing orientations to the writing proficiency construct by native and non-native english speaking teacher raters. it mainly revolved around the international english language testing system (ielts) that is widely administered and employed as a measure of general proficiency in englis...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی - دانشکده ادبیات و زبانهای خارجی 1391

although there are studies on pragmatic assessment, to date, literature has been almost silent about native and non-native english raters’ criteria for the assessment of efl learners’ pragmatic performance. focusing on this topic, this study pursued four purposes. the first one was to find criteria for rating the speech acts of apology and refusal in l2 by native and non-native english teachers...

2016
Shufeng Fan Haihao Yu Xianru Dong Ligong Wang Xiuwen Chen Dan Yu Chunhua Liu

Host-enemy interactions are vital mechanisms that explain the success or failure of invasive plants in new ranges. We surveyed the defoliation of invasive Alternanthera philoxeroides and co-occurring native plants on two islands during different seasons over three consecutive years and measured the leaf nitrogen content and the C/N ratio of each plant species. To evaluate the effects of herbivo...

2016
Natasha Shelby Philip E. Hulme Wim H. van der Putten Kevin J. McGinn Carolin Weser Richard P. Duncan

The evolution of increased competitive ability (EICA) hypothesis could explain why some introduced plant species perform better outside their native ranges. The EICA hypothesis proposes that introduced plants escape specialist pathogens or herbivores leading to selection for resources to be reallocated away from defence and towards greater competitive ability. We tested the hypothesis that esca...

Fatemeh Akbarpour Majid Seyri Mohamad Akbarpour

Plant biomass harvested after heavy-metal phytoremediation must be considered as a hazardous waste that should be contained or treated appropriately before disposal or reuse. This study provides an evaluation of extractants for the removal of lead from Abutilon Theophrastus biomass. The research was carried out a leaching study to determine the lead-extraction efficiency of the different leacha...

2017
Guang Song Xinrong Li Rong Hui

Biological soil crusts (BSCs) can improve the stability and health of native plant communities in arid ecosystems. However, it is unknown whether BSCs can also inhibit invasions of exotic vascular plants on stabilized reclaimed sand dunes. To answer this question, we conducted a greenhouse experiment to test the effects of cyanobacteria-dominated BSCs on 1) seed germination and biomass of an ex...

2008
Heather L. Bateman Alice Chung-MacCoubrey Howard L. Snell

Many natural processes in the riparian cottonwood (Populus deltoides) forest of the Middle Rio Grande (MRG) in the southwestern United States have been disrupted or altered, allowing non-native plants such as saltcedar (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) to establish. We investigated reptilian responses to restoration efforts by sampling communities of lizards at 12 study ...

2011
Llewellyn C Foxcroft Vojtěch JaroŠÍK Petr Pyšek David M Richardson Mathieu Rouget

Human land uses surrounding protected areas provide propagules for colonization of these areas by non-native species, and corridors between protected-area networks and drainage systems of rivers provide pathways for long-distance dispersal of non-native species. Nevertheless, the influence of protected-area boundaries on colonization of protected areas by invasive non-native species is unknown....

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید