KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 莫索湾地区白梭梭幼苗的发生和生长与环境因子的关系 | |
| 李亚萍 | |
| Subtype | 硕士 |
| Thesis Advisor | 蒋进 |
| 2018-06-01 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 新疆乌鲁木齐 |
| Degree Discipline | 农学硕士 |
| Keyword | 白梭梭幼苗 环境因子 立地条件 存活率 莫索湾 Haloxylon persicum seedlings environmental factors site conditions survival rate Mosse |
| Abstract | 白梭梭幼苗的发生与生长受不同环境因子等条件的限制表现不同，本研究通过了解古尔班通古特沙漠白梭梭的萌发特性、幼苗生长及与环境因子之间的关系， 对白梭梭种群更新与环境因子之间的关联有重要理论意义，以及在白梭梭的物种保护方面提供科学依据， 同时对北疆沙漠的生态系统稳定起到支撑的作用。 选取古尔班通古特沙漠南缘莫索湾地区发育近 SN 向的纵向沙垄，按照植被盖度分布的不同，依次选取植被总盖度为 10%（沙丘 A） 、 15%（沙丘 B） 、30%（沙丘 C）的沙丘作为实验样地，其中，沙丘 A 和沙丘 B 群落主要以白梭梭为主的半固定沙丘， 伴随有少量的沙拐枣，沙丘 C 主要以红柳为主，白梭梭数量占整体盖度的 2%~5%。所选样地包括 3 条沙垄，每两沙垄垄顶间距约 200m，沙垄顶部与垄间地的最大落差为 8 m。 运用动态生命表观察和分析苗期幼苗的存活状况，了解环境因子对白梭梭幼苗在发生与生长期间的作用。结果表明：白梭梭幼苗大量分布在半固定沙丘的迎风坡上部、坡顶和背风坡，随着白梭梭植被总盖度的增大，其幼苗的数量亦成增大的趋势。 固定沙丘由于白梭梭群落密度较少， 幼苗的数量显著地小于半固定沙丘。将环境因子指标与白梭梭幼苗的密度进行显著性检验， 结果发现， 土壤细沙的含量与白梭梭幼苗的数量成极显著的正相关（R2=0.996），与土壤 pH（R2=0.72）和电导率（R2=0.58）、土壤有机质（R2=0.64）、土壤全 N（R2=0.80）呈显著的正相关。不管是半固定沙丘还是固定沙丘，白梭梭幼苗更新的共同影响因子有坡度、坡向、坡位、土壤含水量、土壤养分、物种的多样性。坡度、坡向改善局部的土壤水分、光照以及养分，在条件较好的情况下，白梭梭幼苗的生长状况较好，更新的数量也较多。用典范排序（CCA）的方式对该地区样方、环境因子以及物种多度之间进行对应分析，了解物种多样性对白梭梭幼苗发生与生长的影响，结果表明， 物种与环境因子之间存在显著的相关关系， 土壤粒度是影响物种分布一个较为敏感的指示性因子，物种大量分布在土壤砂粒所在的排序轴上，与白梭梭生长立地相似的物种有倒披针叶虫实、鹤虱、天芥菜、三芒草、土大戟等，这些种与白梭梭幼苗共同竞争水分、养分等。 地形因子中，坡向主要影响物种丰富度指数 simpson；土壤理化因子中，砂粒和土壤有机质主要影响优势度指数 shannon,土壤含水量和 pH 主要影响均匀度指数 pielou。该区域物种分布状态是由地形和土壤因子共同作用所控制的。在各沙丘苗期动态生命表以及幼苗期存活率曲线可知，白梭梭在幼苗期存活率各沙丘表现不同，但是开始大幅度死亡的时期相差不多。白梭梭幼苗的第一死亡高峰期从 4 月 15 日~5 月 25 日，主要死亡的原因是早期幼苗脆弱，抵抗外界环境胁迫的能力弱；幼苗第二死亡高峰期发生在 6 月 15 日~8 月 5 日，该阶段导致幼苗大量死亡的原因是土壤水分的供应不足。在植被盖度为 10%的半固定沙丘，白梭梭幼苗苗期总死亡率达到 74%，该时段的死亡率达到了 44.4%；植被盖度为 15%的沙丘，死亡率达到 80.9%，幼苗苗期的总死亡率为 95.5%；在植被盖度为 30%的固定沙丘，幼苗苗期死亡率为 50%；幼苗第三阶段的死亡主要在 10 月份以后，由于沙鼠采食，白梭梭幼苗无法越冬，完成一个生长季。总体上，半固定沙丘白梭梭幼苗的数量在早期（4~6 月）大于固定沙丘，但是后期（9~10 月）存活率小于固定沙丘。通过多元线性回归模型的方法综合分析了不同植被覆盖度下的各沙丘环境因子与白梭梭更新苗数量和植株生长量之间的关系， 结果发现： 土壤含水量、沙丘的坡度、坡向、坡位是白梭梭更新共同的影响因子，由于不同的微地形下，环境因子产生差异， 在条件较好的情况下，白梭梭幼苗的生长状况较好，更新的数量也较多。在沙区，风沙、干旱、虫害对幼苗的危害非常严重，种子的成苗受多种因素的影响，该地区保存下来的幼苗数量极少并且幼树的株数也较少，白梭梭天然更新状况不良。 |
| Other Abstract | Because of environmental factors and other conditions, the occurrence andgrowth of Haloxylon persicum seedlings show different effects at different years. Byunderstanding the germination characteristics, seedling growth, and environmentalfactors of Haloxylon persicum in the Gurbantunggut Desert, it is of great theoreticalsignificance to correlate populations of Haloxylon persicum with environmentalfactors. It provides scientific basis for the species protection of Haloxylon persicumand supports the stability of the ecosystem in the northern desert. The vertical sagalong the SN direction in the Mossel Bay area on the southern margin of theGurbantunggut Desert was selected. According to the distribution of vegetationcover, dune A with a total coverage of 10% and sand dune with a coverage of 15%were selected in order B. The sand dunes of the dune C with a coverage of 30% wereused as experimental plots. Among them, dune A and dune B communities weremainly semi-fixed sand dunes mainly composed of Haloxylon persicum and a smallamount of sand calluses, and the dunes C were mainly dominated by red willows.Haloxylon number accounts for 2%~5% of the overall coverage. The selected plotincludes three sand ridges, each with a ridge spacing of about 200 m, and amaximum drop of 8 m between the ridge roof and the ridge. Using a dynamic lifetable to observe and analyze the seedling survival at seedling stage to understand theeffect of environmental factors on the occurrence and growth of Haloxylon persicumseedlings. The results showed that the seedlings of Haloxylon persicum weredistributed in the upper part of the windward slope, the top of the slope and theleeward slope of the semi-fixed sand dunes. With the increase of the total coverageof Haloxylon persicum, the number of seedlings also increased. Fixed dunes Due tothe lower density of Haloxylon persicum community, the number of seedlings issignificantly smaller than that of semi-fixed sand dunes.The environmental factor index and the density of Haloxylon persicum seedlingswere tested for significance. The results showed that there was a very significantpositive correlation between the content of soil fine sand and the number ofHaloxylon persicum seedlings (R2=0.996). The content of soil fine sand wassignificantly positively correlated with the number of Haloxylon persicum seedlings(R2=0.996), soil pH (R2=0.72) and electrical conductivity (R2=0.58), soil organicmatter (R2=0.64), soil N (R2 = 0.80) showed a significant positive correlation.Whether it is a semi-fixed dune or a fixed dune, the common influencing factors forthe regeneration of Haloxylon persicum seedlings include slope, aspect, slopeposition, soil moisture, soil nutrients, and species diversity. the main reason is thatthe slope, the aspect of the improvement of local soil moisture, light and nutrients,under better conditions, the growth condition of Haloxylon persicum seedlings isbetter, and the number of renewal is also more.Model for sorting (CCA) manner between the corresponding analysis of the plots,environmental factors and species abundance area, understanding species diversitywith the dialogue from the Seedling Growth results showed: there is a significantcorrelation between species and environmental factors. Soil particle size is arelatively sensitive indicator factor that affects species distribution. Species arewidely distributed on the ordination axis of soil sand. Species similar to the growthsite of Haloxylon persicum include P. apoides, Helicoptera, Heliotrope, Sanmaigrass, and Tadpole. These species compete with H. amurensis for water, nutrients,etc. In the topographic factors, the slope direction mainly affects the species richnessindex simpson; in the soil physicochemical factors, sand and soil organic mattermainly affect the dominance index shannon, and the soil moisture and pH mainlyaffect the evenness index pielou. The regional distribution of species by interactionterrain and soil factors controlled. It can be seen in the seedling stage dune dynamiclife table and seedling survival curves, different persicum at the seedling stage thesurvival rate of each dune performance, but the beginning of a significant period ofalmost the same death, The first death peak of Haloxylon seedlings from April15-May 25, The main cause of death is early seedling fragile, resistance to externalenvironmental stress weak. The second peak of the inadequate supply of seedlingdeath occurred in June 15 - August 5, at this stage the cause of death of a largenumber of seedlings is soil moisture. In the semi-fixed dunes vegetation coverage of10%, the total seedling mortality 74% white the Seedling mortality this periodreached 44.4%. For sand dunes with a vegetation cover of 15%, the mortality rate is80.9%, and the total mortality of seedlings during seedling stage is 95.5%. In a fixedsand dune with a 30% coverage of vegetation, the seedling mortality rate is 50%.The third stage of the seedling‟s death was mainly after October. Due to the gerbilfeeding, the Haloxylon persicum seedlings could not overwinter and complete agrowing season.The multiple linear regression model was used to comprehensively analyze the relationship between the environmental factors of each dune under differentvegetation coverage and the number of regeneration seedlings and the growth ofHaloxylon persicum, and found that soil moisture content, slope, slope direction andslope position of sand dunes are the common influencing factors for the regenerationof Haloxylon persicum. Since different microtopography, a difference inenvironmental factors, in good conditions, preferably white from the Seedlinggrowth conditions, the number of updates is greater. In Sand, sand, drought, pests arevery serious damage to seedlings, seedling seed is affected by many factors, thenumber of surviving seedlings and saplings of very few in the region fewer numberof trees, natural regeneration persicum. |
| Subject Area | 水土保持与荒漠化防治 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/14973 |
| Collection | 研究系统_荒漠环境研究室 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 李亚萍. 莫索湾地区白梭梭幼苗的发生和生长与环境因子的关系[D]. 新疆乌鲁木齐. 中国科学院大学,2018. |
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