Monthly rainfall data given by surface meteorological observations during the period 1961-2007 in Central Vietnam is used to calculate drought indices. Results show that drought conditions slightly increase in North Central Vietnam but decrease in South Central and Highland Central Vietnam. Significant drought periods often occur from January to March. The percentage of dry years during the period 1961-2007 is larger than that in the reference period of 1961-1990 in North Central while smaller in South Central and almost similar to that in Highland Central Vietnam.
Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Drought conditioning improves water status, stomatal conductance and survival of Eucalyptus globulus subsp. bicostata seedlings...
Rice is one of the most important crop plants over the world. Our work studied on the physiological responses of rice seedlings (Oryza sativa cv. Dongjin) under drought condition by withholding water. In response to drought treatment, three-week-old rice seedlings exhibited typically morphological responses as leafs rolling and drying at 48 h after exposure to water deficit.
Dữ liệu lượng mưa hàng tháng được đưa ra bởi các quan sát khí tượng bề mặt trong thời gian 1961-2007 ở miền Trung Việt Nam được sử dụng để tính toán các chỉ số hạn hán. Kết quả cho thấy rằng các điều kiện hạn hán hơi tăng ở Bắc Trung Bộ Việt Nam nhưng lại giảm ở Nam Trung Bộ và Tây Nguyên Việt Nam. Đáng kể thời gian hạn hán thường xảy ra từ tháng một-Tháng ba.
Read the text carefully and then choose the correct answers
A .Drought is a condition that results when the average rainfall for a fertile area drops far below the normal amount for a long period of time. In areas that are not irrigated
Plants are sessile organisms and as such must have mechanisms to deal with both abiotic
and biotic stresses to ensure survival. The term “abiotic stress” includes many stresses
caused by environmental conditions such as drought, salinity, UV and extreme
temperatures. Due to global climate change it is predicted that abiotic stresses will increase
in the near future and have substantial impacts on crop yields (Intergovernmental Panel of
Climate Change; http://www.ipcc.ch).
Microalgae are prokaryotic or eukaryotic photosynthetic microorganisms that can grow
rapidly and live in a wide range of ecosystems extending from terrestrial to aquatic
environment. Environmental factors such as temperature, UV-light, irradiance, drought and
salinity are known to affect their photosynthesis.
Photosynthesis was the most sensitive process in microalgae, leading to numerous changes
in structure and function of the photosynthetic apparatus under various conditions.
Under certain conditions, lichen floristic and community analyses can be used in conjunction with
measured levels of ambient or depositional pollutants accumulated by lichens to detect effects of changing
air quality on vegetation. This information can demonstrate whether air pollutants cause undesirable
changes in species composition or presence/absence of lichen species within terrestrial plant communities.
It is important that any alternative hypotheses (e.g.
Stresses on the climate system are already causing impacts on Earth’s surface.
These include not only rising surface temperatures, but also increasingly frequent
ﬂoods and droughts, and changes in natural ecosystems, such as earlier ﬂower-
ing of plants, and poleward shifts in the distribution of several species. All of
these changes are inextricably linked to the health of human societies.