کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4393774 1618282 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Heliotropium europaeum only germinates following sufficient rainfall to allow reproduction
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Heliotropium europaeum only germinates following sufficient rainfall to allow reproduction
چکیده انگلیسی

Regions with Mediterranean climates are seasonally arid and provide a niche for ephemeral species which germinate following discrete and variable rainfall during summer. These species must be able to detect when conditions are suitable for completion of their life cycle. Common heliotrope (Heliotropium europaeum) is one such species. It is considered a weed in its naturalised habitat in southern Australia as it uses resources that could be used by ensuing crops, and is toxic to livestock.We examined common heliotrope's germination responses to temperature and water potential, the effect of simulated rainfall on seedling emergence and plant growth in lysimeters.Fresh seeds of common heliotrope have relatively high optimum temperatures and water potentials for germination (around 35 °C and 0 MPa). Germination percentage of seeds extracted from the soil seed bank varies seasonally. In the soil types and climate of the study area, 24.2 mm is the minimum amount of rainfall resulting in emergence. Evapotranspiration required to reach minimal reproductive output was 19.4 mm.Common heliotrope's germination requirements have been selected to ensure that it will only germinate after sufficient rainfall to allow reproductive output. This is the mechanism through which common heliotrope detects its temporal niche.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Arid Environments - Volume 73, Issues 6–7, June–July 2009, Pages 602–610
نویسندگان
, , ,