The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to cli...The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to climate change had experienced several cycles in the Holocene,and the evolutionary process can be distinguished by four dominant stages according to changing trends of the environment and climate.(1) Holocene Ameliorative Period(11.0-8.7 cal ka B.P.),when the desert area gradually shrank following an approaching warm-wet climate and strengthening summer monsoon.(2) Holocene Optimum(8.7-6.0 cal ka B.P.),when the majority of moving sand dunes were stabilized and vegetation coverage quickly expanded in a suitable warm-wet climate and a strong summer monsoon.(3) Holocene Multivariate Period(6.0-3.5 cal ka B.P.),during a low-amplitude desert transformed between moving and stabilized types under alternating functions of cold-dry with warm-wet climate,and winter monsoon with summer monsoon.(4) Holocene Decay Period(since 3.5 cal ka B.P.),when the desert area tended to expand along with a weakened summer monsoon and a dry climate.展开更多
In order to explore the characteristics of climate change in the Hunshandake Sandy Land,the number of gale days,sandstorms,and extreme precipitation events in the sandy land from 1956 to 2018 were analyzed.The results...In order to explore the characteristics of climate change in the Hunshandake Sandy Land,the number of gale days,sandstorms,and extreme precipitation events in the sandy land from 1956 to 2018 were analyzed.The results show that in the Hunshandake Sandy Land,the number of gale days was the largest in spring;it first increased and then decreased from 1956 to 2018.The number of gale days was large from 1955 to 1980,and decreased in fluctuation after 1980.Sandstorms mainly occurred in spring;the number of sandstorm days first increased and then decreased.It was the largest during 1966-1970,and then decreased slowly;it was the smallest during 1996-2000.with the anomaly of about-0.16 d;it rose after the 21 stcentury.The threshold of extreme precipitation in the sandy land was high in the south and low in the north.The threshold exceeded 80 mm in the southern part of the sandy land,and was less than 50 mm in sandy hinterland and its northern part.The total frequency of extreme precipitation in the sandy land showed an increasing trend year by year.Especially after 1982,the frequency of extreme precipitation rose obviously.Extreme precipitation events mostly happened in July and August.The frequency of extreme precipitation events was the highest in Abaga Banner and the lowest in Duolun County.The maximum daily precipitation appeared in Duolun County,reaching 142.3 mm.展开更多
Salix gordejevii, a species of dune-fixing pioneer shrub in the Hunshandak Sandland in China, plays a vital role in maintenance and improvement of the local ecological environment. Salix gordejevii has an r-type repro...Salix gordejevii, a species of dune-fixing pioneer shrub in the Hunshandak Sandland in China, plays a vital role in maintenance and improvement of the local ecological environment. Salix gordejevii has an r-type reproductive countermeasure, which means it produces large quantifies of seeds that have a high germination rate but relatively low seedling viability. Our research on the seed regeneration and sprouting regeneration characteristics of Salix gordejevii shows that its sprouting regeneration process is more productive and efficient than its seed regeneration process. At the same time, growth of Salix gordejevii would decline when the drifting sand dune was fixed. To assess its sprouting regeneration process, we analyzed the number, length, and diameter of new shoots under different cutting treatments, and found significant differences based on various cutting heights and different cutting times （April vs. October）. We conclude that cutting measures which take advantage of this species＇ robust sprout tillering can in- crease the biomass of this shrub and also can improve its canopy density and its forage properties for livestock grazing, with the added benefits of improved sand-fixing and prevention of wind erosion.展开更多
基金by the Chinese National Natural Science Foundation (40971005)
文摘The Hunshandake Desert is located at the northern edge of the East Asian monsoon region,and its natural environment is sensitive to monsoonal changes.Geologic records suggest that desert evolution corresponding to climate change had experienced several cycles in the Holocene,and the evolutionary process can be distinguished by four dominant stages according to changing trends of the environment and climate.(1) Holocene Ameliorative Period(11.0-8.7 cal ka B.P.),when the desert area gradually shrank following an approaching warm-wet climate and strengthening summer monsoon.(2) Holocene Optimum(8.7-6.0 cal ka B.P.),when the majority of moving sand dunes were stabilized and vegetation coverage quickly expanded in a suitable warm-wet climate and a strong summer monsoon.(3) Holocene Multivariate Period(6.0-3.5 cal ka B.P.),during a low-amplitude desert transformed between moving and stabilized types under alternating functions of cold-dry with warm-wet climate,and winter monsoon with summer monsoon.(4) Holocene Decay Period(since 3.5 cal ka B.P.),when the desert area tended to expand along with a weakened summer monsoon and a dry climate.
基金Supported by Science and Technology Plan Project of Xilin Gol League,Inner Mongolia Autonomous Region (201802)Natural Science Foundation of Inner Mongolia Autonomous Region (2021MS04019)。
文摘In order to explore the characteristics of climate change in the Hunshandake Sandy Land,the number of gale days,sandstorms,and extreme precipitation events in the sandy land from 1956 to 2018 were analyzed.The results show that in the Hunshandake Sandy Land,the number of gale days was the largest in spring;it first increased and then decreased from 1956 to 2018.The number of gale days was large from 1955 to 1980,and decreased in fluctuation after 1980.Sandstorms mainly occurred in spring;the number of sandstorm days first increased and then decreased.It was the largest during 1966-1970,and then decreased slowly;it was the smallest during 1996-2000.with the anomaly of about-0.16 d;it rose after the 21 stcentury.The threshold of extreme precipitation in the sandy land was high in the south and low in the north.The threshold exceeded 80 mm in the southern part of the sandy land,and was less than 50 mm in sandy hinterland and its northern part.The total frequency of extreme precipitation in the sandy land showed an increasing trend year by year.Especially after 1982,the frequency of extreme precipitation rose obviously.Extreme precipitation events mostly happened in July and August.The frequency of extreme precipitation events was the highest in Abaga Banner and the lowest in Duolun County.The maximum daily precipitation appeared in Duolun County,reaching 142.3 mm.
基金supported by the National Natural Science Foundation of China(Grant No.30560128)the Special Research Funds of the Doctoral Program of Higher Education(No.20070129004)
文摘Salix gordejevii, a species of dune-fixing pioneer shrub in the Hunshandak Sandland in China, plays a vital role in maintenance and improvement of the local ecological environment. Salix gordejevii has an r-type reproductive countermeasure, which means it produces large quantifies of seeds that have a high germination rate but relatively low seedling viability. Our research on the seed regeneration and sprouting regeneration characteristics of Salix gordejevii shows that its sprouting regeneration process is more productive and efficient than its seed regeneration process. At the same time, growth of Salix gordejevii would decline when the drifting sand dune was fixed. To assess its sprouting regeneration process, we analyzed the number, length, and diameter of new shoots under different cutting treatments, and found significant differences based on various cutting heights and different cutting times （April vs. October）. We conclude that cutting measures which take advantage of this species＇ robust sprout tillering can in- crease the biomass of this shrub and also can improve its canopy density and its forage properties for livestock grazing, with the added benefits of improved sand-fixing and prevention of wind erosion.
