Subjects: Biology >> Botany submitted time 2023-08-26 Cooperative journals: 《干旱区研究》
Abstract： In order to explore the succession and species diversity of plant communities in the process of ganguetreatment, the text used the time-space substitution method to select the different years (2, 5, and 10 a) of ganguetreatment in Shuanglong ditch, Tianzhu Tibetan Autonomous County, Gansu Province, and the untreated gangueas the contrast (CK) sample plots . The vegetation was surveyed, and the succession characteristics and speciesdiversity of plant communities were analyzed. The results show that: (1) during the process of Shuanglong ditchgangue treatment, we identified 55 species of plants belonging to 40 genera and 24 families in 4 sample plots.Among these taxa, 15 families were single families, single genus, and single species. There were 28 species ofAsteraceae, Poaceae, and Rosaceae, which accounted for 12.5% of the total number of families and 50.91% ofthe total species. Most of the species belonged to a few families, and most plant species belonged to a singlefamily and a single genus. (2) During the years of gangue treatment, the dominant species of the communitygradually changed from annual or perennial herbs to perennial herbs and shrubs. The number of plant species inthe CK was 11, and after 5 years of gangue treatment, we identified 28 species, which decreased to 18 speciesafter 10 years of gangue treatment. Finally, Elymus nutans, Poa pratensis, and Hippophae rhamnoides becomethe dominant species in the sample plot; and these three plants comprised 48.107. (3) With increasing ganguetreatment time, the number of species, Shannon diversity index, and Margalef richness index gradually increasedfrom CK to 5 years after gangue treatment, reaching maximum values of 28, 3.506, and 2.877 respectively. ThePielou evenness index changed little, although we observed a trend of“falling- rising- falling.”In contrast, theSimpson dominance index showed a trend of“rising-falling-rising,”reaching the maximum value of 0.359 after10 years of gangue treatment. (4) The length of time of gangue treatment greatly impacted the quantitativecharacteristics of the plant population. Plant height significantly increased from CK, 2-10 a (P < 0.05). Coveragesignificantly increased from CK to 5 a and 10 a of treatment (P < 0.05). The number of plants increasedsignificantly from CK to 10 a of treatment (P < 0.05). Overall, the results indicate that years of gangue treatmentgreatly impacted vegetation succession and species diversity in the Shuanglong ditch of the eastern section ofQilian Mountains; and the plant community has gradually become single and stable.
Subjects: Biology >> Ecology submitted time 2023-08-26 Cooperative journals: 《干旱区研究》
Abstract： Sand bound land protection area (sand bound area) is an important means to prevent desertification,restore vegetation, maintain ecological security, and promote sustainable economic and social development ofcontiguous sand bound land that does not have control and development. As primary body of the operations insand bound area, farmers’construction has an impact on their livelihood. To explore the impact of livelihoodcapital on livelihood strategy selection in this region. This paper adopts the participatory rural assessment method(PRA) and takes Linze County of Zhangye City as an example. Based the sustainable livelihoods approach (SLA)sustainable analysis framework paired with binary logistic regression model. The results show that (1) Naturaland human capital significantly affect the choice of pure agricultural livelihood strategy. Material and socialcapital have significant influence on the choice and agriculture livelihood strategy. Financial capital is the mainfactor of non-agricultural livelihood strategy selection (2) The reserves livelihood capital affect farmers’choiceof different types of livelihood strategies, and the more reserves, the stronger the sensitivity of choice. (3) Thewillingness of different types of farmers to adjust the existing livelihood strategy is very different, 68% of purefarmers and 56% of part- time farmers hope to adjust the existing livelihood strategy; 63% of non- farmers areunwilling to adjust their existing livelihood strategies. The conclusion provides a theoretical basis for improvingthe livelihood and ecological security of local farmers and promoting the sustainable development of socialeconomy.
Subjects: Biology >> Botany submitted time 2023-08-25 Cooperative journals: 《干旱区研究》
Abstract： The effects of different salt types and concentrations on the germination characteristics of Poa annuaseeds were studied using the Petri dish method in this study. The relative germination rate, potential, index, vigor,bud length, radicle length, and salt damage rate were measured, analyzing the responses of P. annua seedgermination and seedling growth to different salt types. The results indicated that: (1) P. annua from Yongchanghad superior germination and seedling growth characteristics compared with the other provenances. (2) varioussalt types and concentrations significantly inhibited seed germination and seedling growth, with alkaline saltsexhibiting stronger toxicity compared with neutral salts, and radicles being more sensitive than buds duringgermination; and (3) the salt toxicity of different salt types during P. annua seed germination ranked as follows:Na2CO3>NaHCO3>Na2SO4>NaCl. Therefore, this study provides a scientific basis for planting P. annua forecological restoration of different types of saline lands.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science submitted time 2023-08-25 Cooperative journals: 《干旱区研究》
Abstract： Rainfall is an important factor affecting water supply and soil respiration in wetland areas. Increases inextreme rainfall variability caused by global climate change are thus expected to impact wetland ecosystems. Toinvestigate this, the changes in soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) inresponse to altered rainfall frequencies (weekly, fortnightly, three- weekly, four- weekly, and control irrigationtreatments) were assessed in a wet meadow in the Gahai-Zecha Nature Reserve on the north-eastern edge of theTibetan Plateau. The SOC was found to increase with increasing rainfall frequency, while TP and TN decreased.SOC and TN decreased with increasing soil depth and TP was inconsistent across the different soil layers. As aresult, the ratios of C:P and N:P decreased with the soil layers, but the ratio of C:N did not show a significantchange. The ratios of C:N, C:P, and N:P did not show significant responses to the rainfall treatments. The SOC,TN, and TP showed obvious seasonal variations, as the SOC showed an increasing and then decreasing trend, theTN showed a decreasing and then increasing trend, and the TP content showed an“M”-shaped decreasing trend.The results suggest that continuous changes in global rainfall, including an increased rainfall frequency, willaggravate the loss of nitrogen and phosphorus in the shallow soil of the alpine wet meadow, likely resulting inaggravated damage due to eutrophication in the water environment surrounding the alpine wet meadows.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science submitted time 2023-05-30 Cooperative journals: 《干旱区研究》
Abstract： In the semi-arid zone of the Liupan Mountains in Ningxia, soil water content is a key factor affecting the survival and growth of trees, and it is necessary to understand the differences in soil water content on different slope positions of forested slopes and their response to different rainfall amounts. For this purpose, a typical slope covered by Larix principis- rupprechtii plantations was selected in the small watershed of Diediegou in the Liupanshan Mountains. From May to October 2021, meteorological conditions (such as precipitation) and changes in soil water content on this slope were continuously monitored with automatic weather stations and soil moisture meters to analyze the differences in soil water content on the slopes and their response to the depth of individual rainfall events. The total precipitation depth during the monitoring period was 443.7 mm, which was close to the long-term annual average, but with severe drought in summer. The results showed the following: (1) The soil water content varied significantly within the growing season; the overall level first decreased and then increased, being the lowest in August (0.112 m3 ·m- 3). (2) There were clear differences in soil water content among slope positions, generally in the order upper slope [(0.191 ± 0.044) m3 ·m- 3] > middle slope [(0.158 ± 0.045) m3 ·m- 3] > lower slope [(0.146 ± 0.034) m3 ·m- 3]. This indicated that the main factor influencing the differences in soil water content along slope positions is the amount of evapotranspiration by forest/vegetation, rather than the redistribution of rainwater along the slope by slope runoff in this dry year. (3) To the same rainfall depth, the response of soil water content on the middle slope was the most sensitive, followed by that on the upper slope, and the lower slope was the least sensitive, owing to the integrated effects of soil porosity, waterholding capacity, and understory vegetation. (4) At the study site, rainfall was dominated by small rainfall events below 10 mm, with 7 mm representing the threshold for effective rainfall, above which the rainfall is likely to alleviate the soil dryness and recharge the soil moisture in the soil layer of 0-20 cm. The results of this study can aid understanding of the variation and spatial distribution of soil water content on forest slopes in semi- arid mountainous areas and help determine the water-carrying capacity of forest/vegetation and integrated
Subjects: Biology >> Ecology submitted time 2023-05-17 Cooperative journals: 《干旱区地理》
Abstract： In order to explore the influence of microtopography on the natural regeneration of Picea crassifolia seedlings in Qilian Mountains, Picea crassifolia forest was selected as the research object, and the topographic parameters (altitude, convexity and slope) of 15 fixed plots in the watershed were divided into four different microtopographic habitats by C-mean fuzzy clustering, and the effects of microtopographic habitats on the renewal characteristics (renewal seedling density, average crown width, mean base diameter and average plant height) of the regeneration seedlings were studied. The results show that: (1) The average crown width and mean base diameter of regenerated seedlings were in the order of low-altitude convex land>high-altitude slope>low-altitude concave land>high-altitude steep slope. The average plant height on high-altitude steep slopes was considerably lower than that in the other three microtopographies. Thus, different altitudes, slopes, aspects, and slope positions considerably affected the survival rate and growth process of regeneration seedlings. (2) The renewal seedling density and average plant height under different microtopographic conditions were as follows: low-altitude concave land, low-altitude convex land, high-altitude slope, and high-altitude steep slope. (3) Most of the regenerated seedlings showed an aggregated distribution under different microtopography in the order of high-altitude steep slope>low-altitude concave>low-altitude convex>high-altitude slope. (4) The results of the correlation analysis showed that there was a significant correlation between altitude, slope, slope position, and regenerated seedlings (P<0.05). In summary, the natural regeneration of Picea crassifolia forest was significantly affected by microtopographic habitat (P<0.05), and seedlings were more suitable for settlement and growth in low-altitude convex land and low-altitude concave land.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2021-01-26 Cooperative journals: 《干旱区研究》
Abstract：以科尔沁沙质草地为研究对象，研究了短期内极端干旱（减雨60%和干旱60 d）和氮添加（20 g·m-2·a-1）对植物群落物种多样性、叶性状和生物量的影响。结果表明：水、氮变化改变了群落中优势物种的重要值，其中优势物种砂蓝刺头和黄蒿的重要值在短期极端干旱和氮添加处理下明显增加。短期内极端干旱对植株高度（Hight,H）、叶片氮含量（Leaf Nitrogen Content, LNC）及地上生物量有显著影响，减雨60%降低了H，而增加了LNC，生物量在减雨60%和干旱60 d处理下均显著降低，物种多样性、比叶面积（Specific Leaf Area, SLA）、叶干物质含量（LeafDry Matter Content, LDMC）及叶碳含量（Leaf Carbon Content, LCC）在不同干旱处理间均无显著差异。短期氮添加对植物叶性状及地上生物量有显著影响，H、SLA和LNC在氮添加处理下增加，而LDMC降低，植物多样性无显著变化。极端干旱与氮添加两者交互作用对物种多样性、叶性状及生物量均无显著影响。相关回归分析表明，物种多样性、SLA、LDMC、LCC及LNC与生物量无显著相关关系，而H与生物量显著正相关。半干旱沙质草地一年生为主的植物群落通过改变优势物种关键性状来适应极端干旱和氮沉降，其中H对草地生产力的维持有较大的影响。
Subjects: Geosciences >> Geography submitted time 2019-11-15 Cooperative journals: 《干旱区地理》
Abstract：以祁连山排露沟流域青海云杉林为研究对象，研究了海拔梯度上土壤肥力因子的分布特征及变化规律，并运用主成分分析法对青海云杉林土壤肥力状况进行了评价。结果表明：（1）研究区土壤呈碱性，pH值均大于8.0；高海拔地区（3 300 m）含水量达到过饱和状态，各土层含水量均大于100%；随海拔升高，全氮含量呈增大趋势，全钾含量呈减小趋势，而全磷含量呈先减小后增大趋势；不同海拔梯度速效磷含量差异不显著（P>0.05），海拔3 300 m处速效钾含量显著高于其他海拔段（P3 200 m>3 100 m>3 000 m>2 900 m。
Subjects: Geosciences >> Geography submitted time 2019-11-15 Cooperative journals: 《干旱区地理》
Abstract：甘肃河西地区经过60多年的防沙治沙，在绿洲边缘形成了一条积沙带。民勤绿洲边缘积沙带高4.8~18.6 m，宽30.4~461.4 m。为什么有的地段积沙带高大，而有的地段积沙带相对矮小，或者有的地段积沙带较宽，而有的地段积沙带较窄？对此，以民勤为研究区，通过对民勤绿洲边缘积沙带进行了调查，运用相关分析等方法和SPSS软件进行了分析。结果表明：（1） 民勤绿洲边缘积沙带按形成方式可分为天然灌丛积沙带、乔木林带积沙带、人工固沙林积沙带3种，其中天然灌丛形成的积沙带相对高大，而农田边缘单纯的乔木林带形成的积沙带最窄。（2） 控制积沙带高度的环境因子主要是积沙带与主风向的夹角，即积沙带与主风向的夹角越小，则积沙带的高度越低。上风向对准风沙口时，则积沙带与主风向的夹角越小，积沙带的宽度亦越小。（3） 典型相关分析结果好于单相关分析。结果显示，积沙带的形态主要是由其宽度、宽高比和断面形状决定的，而影响积沙带形态特征的环境因子主要是上风向是否对准风沙口以及沙源的距离，亦即当上风向未对准风沙口时积沙带较宽且断面积较大，积沙带与上风向沙源距离越小则积沙带越高大。
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