Desertification is acknowledged as a significant global ecological challenge. In the current context of advancing ecological governance and sustainable development, it is imperative to explore optimal solutions that reconcile economic and ecological interests. This study examined the economically viable crop Jerusalem artichoke (Helianthus tuberosus L.) by selecting four varieties (Qingyu Nos. 1 to 4) for cultivation in the semi-arid sandy region of the Qinghai Plateau. This research analyzes and discusses the growth and development as well as the ecological adaptability of the various varieties, evaluating their feasibility for ecological restoration in high-altitude, semi-arid, sandy environments. The findings suggest that, under high-altitude and semi-arid conditions, these varieties demonstrate a spectrum of physiological and ecological adaptations, including alterations in organ allocation, limited vegetative growth, and modifications in root distribution. Notably, Qingyu Nos. 1 and 2 are more adept at thriving under cold and dry conditions, whereas Qingyu Nos. 3 and 4 are more suitable for cultivation in warmer and humid environments. This study offers valuable insights into crop cultivation in high-altitude, semi-arid, desert regions and proposes innovative strategies for the advancement of the local sand industry. The ecological restoration approach that employs these crops for sand stabilization enhances the transformation of ecological benefits.

The processes of species obtaining water resources are crucial to evaluate the adaptability of plantations, which can affect the establishment and survival of restored ecosystems and functions of water-limited ecosystems. However, there are still limitations in understanding water use patterns of different four plantations (Populus sylvestris, Salix cheliophe, Hippophae rhamnoides and Artemisia ordosica) in the Qinghai Lake basin. Stable isotopes of xylem water of four individual species were analysed at different dunes located at the eastern shore of Qinghai Lake in 2018 and 2019. The purpose of this study was to explore potential water sources used by different life form plants, to identify whether the soil moisture content and root distribution determined the plants water use patterns. Results from the MixSIAR models showed that all species mainly uses three levels of soil water, but they extracted soil water from different layers in different growing seasons among species. All species primarily depended on water from upper soil layers at the early growing stage, but P. sylvestris and S. cheliophe also absorbed much proportion middle and deep soil layers’ water in dry year of 2019. All four species shift to use middle or deep soil layer water rather than shallow water in July with the most rainfall and soil water content. However, it was only used by P. sylvestris and H. rhamnoides in 2018. In all, seasonal water use pattern of different species was affected by soil water content, soil texture and root distribution. Compared with moratorium plantations such as S. cheliophe, mixed afforestation of P. sylvestris and H. rhamnoides maximized of soil water sources absorbed by the plants. The study can shed light on plant-water relationships to facilitate the woody species for afforestation and desertification restoration management in the semi-arid desert ecosystem.

土地沙化是青海高原面临的最严重的生态问题之一.沙化土地主要分布在柴达木盆地、共和盆地、青海湖环湖地区、黄河源区和长江源区.其中青海湖周边地区沙漠化土地是生态建设的重点和难点.因此,在此区域开展治沙造林模式示范,人工植被与气候、土壤环境的相互作用机制等研究,不仅对青海湖周生态环境保护和建设有重要意义,而且对青海湖区社会经济发展的影响深远,同时可以为高寒沙区的防沙治沙提供技术支撑和科学依据,并为沙漠化防治规划提供理论支持.

土壤粒度组成是最重要的土壤物理性质之一,影响着土壤水分运移、植被生产力等,进而影响植被的分布格局.本文以青藏高原东北部共和盆地干涸湖盆——英德海为研究对象,通过野外植被样方调查及室内土壤粒度试验,分析湖盆不同地貌类型和不同景观下的土壤粒度组成特征.结果表明:(1)英德海湖盆从底部至北部边缘,垂直高度为65 m,在湖盆内部,植被从湖盆底部到顶部表现出条带状的分布格局,湖盆底部从东向西也出现植被分布的水平分异性.(2)本区地表沉积物以中砂(0.25～0.50 mm)和细砂(0.125～0.25 mm)为主,英德海湖盆东部和西部地表沉积物的粒度组成无明显差异(P＞0.05),但沉积物的垂直分布模式不同.英德海湖盆地表沉积物的粒度分布差异与地形及植被分布有着密切的联系,植被的分布格局受到地表沉积物的粒度组成的影响,同时,植被与气候条件也对地表沉积物的组成具有反馈作用.本区植被分布格局具有明显的垂直和水平分异特征,植被的这种分布格局不仅受到地形、土壤、气候等因素的单一影响,还受到水文过程的作用,因此,在后期的研究中应关注湖盆植被分布格局与生态水文过程的响应反馈机制.

乌柳是高寒半干旱沙地植被恢复中常用的灌木树种,对乌柳水分利用来源的研究有助于理解沙地人工生态系统的稳定性维持及可持续发展.在青海湖湖东沙地,以沙丘不同地貌部位(迎风坡、丘顶和背风坡)生长的乌柳为研究对象,利用IsoSource模型分析植物生长季内的水分利用来源.研究结果表明:在生长季内,乌柳主要利用3个层次的土壤水,但不同地貌部位的乌柳在不同生长季利用不同层次的土壤水.生长季初期,迎风坡的乌柳以深层(60-150cm)土壤水为主要水源(50.28±18.11)％,而丘顶和背风坡的乌柳主要利用表层20cm的土壤水,利用比例分别为(79.96±7.59)％和(53.47±6.47)％.生长季中期,迎风坡的乌柳更多地利用中层20-60cm土壤水(45.52±26.91)％,丘顶的乌柳主要利用表层土壤水(45.17±20.14)％,而背风坡的乌柳以深层土壤水为主要水源(39.26±23.28)％.生长季末期,迎风坡的乌柳仍以(46.07±27.17)％的比例利用中层土壤水,丘顶的乌柳转而利用深层土壤水(44.25±26.23)％,而背风坡的乌柳却以表层土壤水作为主要水源(42.57±18.78)％.不同沙丘地貌部位乌柳对土壤水分的利用模式与其根系分布特征及其下方的土壤含水量具有相关性.

土壤水分是沙地植被格局和过程改变的主要驱动力,也是干旱半干旱区植物生长最大的限制因子.沙漠地区的土壤水分表现出明显的空间异质性.以高寒半干旱沙地青海湖东沙地为研究区,以栽植人工固沙植物(小叶杨、樟子松、沙棘和乌柳)的沙丘和自然固定沙丘(沙蒿为优势种)作为研究样地,探讨不同固沙植物影响下的沙丘不同地貌部位土壤水分变化特征.结果表明:(1)土壤水分的季节变化受降水、植被蒸腾作用和地表蒸发的共同影响,不同物种的分布模式具有差异性,但都表现为7月的土壤含水量最高.(2)同一植物在不同地貌部位的土壤含水量具有差异性,小叶杨在迎风坡最高,樟子松、沙棘和乌柳在背风坡最高,而沙蒿在丘顶最高,但只有乌柳的土壤含水量在沙丘地貌部位间的差异明显(P<0.05).不同植物在同一地貌部位的土壤含水量也具有差异性,迎风坡樟子松的土壤含水量最小,只有1.81％,而沙蒿的土壤含水量能达到3.48％.丘顶处乌柳的土壤含水量仅为1.82％,而沙蒿可达3.58％.背风坡处的土壤含水量相差不大,乌柳最大为3.41％.(3)土壤水分随着土层深度的变化模式不同,土壤含水量整体表现为10～20 cm处最高.不同植物的土壤水分的垂直分布具有差异性,小叶杨和樟子松下方的土壤含水量随着土层深度的增加而降低,沙棘和沙蒿表现为120 cm土层深度内无明显变化,而乌柳下方的土壤含水量随着土层深度的变化在各地貌部位不同,具体表现为迎风坡无明显变化、丘顶降低和背风坡增加的趋势.土壤水分在高寒半干旱沙地不同植被恢复措施下的分布除受到降水、土壤分布、物种类型、植物根系分布的影响之外,还与沙丘微地貌形态具有一定的相关性.

Wind regime, sand drift potential and sand transport amount are important indicators to evaluate regional blown sand activities. This paper took Ketu sandy land on the eastern shore of Qinghai Lake as study area. The sand transport amount data were collected monthly in 2013-2014 and 2016-2017 with 16-azimuth sand collector, and data of local wind velocity and direction were used to compare and analyze the typical blown sand activities. The results were as follows: (1) In 2013-2014, the mean wind velocity in the study area was 2.79m/s and the frequency of sand-driving wind was 6.76%. While they were 2.63m/s and 6.13% in 2016-2017, respectively. (2) The directions of the sand-driving wind in two years were similar, clearly from WSW-WNW and ESE-SSE. The frequency of western wind increased whereas the frequency of southeastern wind decreased. (3) The seasonal variation of sand drift potential in two years were similar with the largest in spring and the smallest in summer. According to the annual variation trend of sand drift potential, the study area was belonging to low wind energy environment. (4) There is a significant difference in sand transport amount between the two years. The amount in 2016-2017 was 77.18kg less than that in 2013-2014, while the distribution of sand transport amount was similar. The increase of vegetation coverage in this area is the main reason for the decrease of sand transport amount.

The planting of sand-binding vegetation in the Qinghai Lake watershed at the northeastern edge of the Qinghai–Tibet Plateau began in 1980. For this paper, we took the desert on the eastern shore of Qinghai Lake as the study area. We analyzed a variety of aged Hippophae rhamnoides communities and aeolian activities, and we discuss the relationship between them. The main conclusions are as follows: (1) With an increasing number of binding years, the species composition became more abundant, natural vegetation began to recover, and biodiversity increased year by year. At the same time, plant height, canopy width, and community coverage increased, but H. rhamnoides coverage was reduced to 36.70% as coverage of Artemisia desertorum increased to 25.67% after 10 years of fixing. The biomass of H. rhamnoides increased significantly, especially the underground biomass. For example, the biomass of area 15a was about 10 to 30 times that of area 1a. (2) Plants are a useful obstacle to aeolian activity. The presence of plants reduced the wind flow in the upper parts of the plants, but it did not have obvious regular characteristics. The longer the fixation term, the lower the surface sediment transport. It is significant that the sediment transport amount in winter was four times that in the summer. After 15 years of binding, H. rhamnoides grows well, and the community is still stable in the study area.

根据格尔木胡扬林自然保护区的数据调查,对天然沙地植被群落结构和物种多样性进行研究,通过分析群落物种组成和生长特征,测定植被重要值、多样性、均匀度、丰富度等.结果表明:1、记录到的植物种类有80种,分属24科,55属.其中以柽柳和唐古特白刺灌木为主,草地植被型以芦苇群落为主.柽柳、枸杞、白刺是该区盐碱沼泽地、退化草地、半固定沙地优势灌木物种,柽柳最具代表性.2、该研究区植物群落普遍较少,物种多样性较小.组成以灌木群落为主,草本群落次之,仅有胡杨纯林为乔木群落.柽柳占有较高的重要值比例,是灌木层的绝对优势树种,草本层中芦苇体现出群落优势种较为明显的局面.3、灌木层物种多样性指数显著高于草本层.灌木盐碱地群落以Simpson多样性指数(D),Shannon-Weiner多样性指数(H),均匀度指数值(J)大小排序,其顺序为:群落三(大叶白麻+柽柳+枸杞)＞群落二(白刺+柽柳)＞群落一(柽柳纯林),草本中芦苇相较于其余6种植物Shannon-Weiner多样性指数(日)显著.