【作者】 满多清；

【导师】 孙坤； 王继和；

【作者基本信息】 西北师范大学 ， 植物学， 2004， 硕士

【摘要】 河西地区天然中麻黄实生苗当年地上部分生长缓慢，地下根系生长显著；第二年3月中、下旬萌发，高生长和分蘖生长显著提高，4-7月为高生长和分蘖生长的关键季节；第三年高生长减弱，达到生物学高度峰值，但分蘖枝数仍成倍增加。3龄天然中麻黄苗在10月底刈割采收后，翌年分蘖生长、高生长迅速；第二年高生长继续增加，但比第一年缓和，分蘖枝数成倍增加；第三年高生长幅度小，并达到其高度峰值，分蘖枝数连续增加，但趋于缓和。三年后，随着生殖生长逐渐旺盛，营养生长处于新老更替状态。同时，根蘖繁殖加强，居群扩大。 对生长多年的天然中麻黄进行刈割试验表明：同一立地条件下实生苗和刈割后的再生草都是生长三年后高度达到最大值，且高度峰值差异不显著。但分蘖枝数却是多年生中麻黄刈割再生草＞3龄实生苗刈割再生草＞实生苗。而生物量累计与营养生长节律成正相关。 天然和人工中麻黄营养生长比较中，不同生境下中麻黄生物学高度不同，而同一生境下高度峰值相似，但人工中麻黄生物学高度显著大于天然生长的，高差达22-23cm。无论是天然苗、人工苗，还是天然刈割再生草、人工刈割再生草，3年内分蘖枝数随生长年限的增加而增加，而人工中麻黄的分蘖枝数显著大于天然的。也就是说，在一定立地条件下，生物学高度峰值是一定的，但分蘖枝数可在较大范围内变化，通过改善生境条件，提高单株分蘖枝数，增加单位面积的麻黄枝数，科学控制刈割期，就可大大提高产量，为人工丰产栽培提供了理论依据。 中麻黄实生苗3龄时已趋于生理成熟，开始有生殖能力，随着年龄的增加逐渐进入盛果期。再生草第二年才有个别枝条开花结实，以后生殖能力逐渐增强，营养生长相对削弱。 麻黄为裸子植物，无宽展的叶片，光合面积小，生殖期营养不足，造成了大多数花的败育，是生物生存竞争的一种策略。但中麻黄开花潜力大，生殖势强，只要生殖期营养满足，结实率显著提高。 中麻黄属根蘖类植物，根系发达，常以群片的方式生长，在已有的中麻黄种群或居群繁殖中，根蘖繁殖是居群扩展的主要方式，而种子则是新居群的建立和发育的主要繁殖方式。在生境适宜的条件下，随着植丛数量的增加，根系伸展，根蘖苗不断产生，向外扩展，扩大居群领域，此时中麻黄种群生产力高，生存竞争力强，使物种结构简单化。若生境恶化，其它物种入侵，麻黄种群趋于衰退。 河西地区中麻黄分布于酒泉市以东，黄河以西的17个县(市)。从生长和分河西地区中麻黄生长发育特征及其影响因子研究布状况看，走廊东段是河西地区天然中麻黄的集中分布区和主要产区，土壤质地以沙壤土、轻壤土、壤土和风沙土为主。随着越往西去，生境恶化，土层渐薄，砂砾表露，中麻黄生长稀疏，生长发育渐弱。经调查分析:土壤有机质在1.0ry0以上中麻黄生长良好，1.0一o.50k生长中等，低于0.5%生长发育状况差。 天然中麻黄大多数分布在含盐量低于1.0%的土壤上，随着河西东段向西延伸，土壤含盐量逐渐上升，中麻黄分布趋于减少。人工种植中麻黄时，应尽量选择土壤含盐量较低的土壤，以便高产丰产;若在含盐量高的土壤上种植，土壤含盐量应蕊1.2%，并进行土壤改良、增加播种量等措施后种植。 在以土壤全盐量、PH值及盐碱离子对中麻黄生物量影响程度的灰色关联分析中，其关联度大小为:土壤全盐量、PH值、5042一、eaZ+、K+刊a+、el一、Heo3一、MgZ+。表明土壤全盐量、PH值和5042一是主导因子，eaZ+、K+创a+、 el一、Heo3一、M犷+关联度较小且相近，对生物量影响相对较小。因此，在河西干旱荒漠区天然中麻黄更新复壮和栽培生产中可以根据这一结论，进行土壤选择和肥料施用。 河西地区中麻黄集中分布在海拔高度1300一2800m的地理范围内，这与温度和干旱有关。中麻黄虽是强旱生植物，在干旱区降雨量较大的区域内生长良好，处于生存竞争中的强者，但在极端干旱区只能生存于低洼、易积水的区域，且生长微弱，它与膜果麻黄、红砂等超旱生植物群落形成明显对比，成为弱势种群。表明水分是影响河西中麻黄分布与生长的主要因子。 经过中麻黄生长年限、水、肥三因素四水平的地上生物量积累的试验研究表明:人工种子种植的4年生中麻黄，其对生物量影响的因素为生长年限>灌水次数>施肥量。方差分析表明，生长年限、灌水次数、施肥量三个因素都达到了F001的极显著水平，说明在人工种植生产的过程中，生长年限、施肥量及灌溉次数均为重要条件，控制好此三因素，就决定了中麻黄生物量积累的多少。中麻黄是节水、节肥植物，根据天然生长和栽培技术的研究，只需耕作农田年灌水量的1/2一1/6以及适量施肥，就可大大提高单位面积上中麻黄的产量和质量。 通过对河西地区中麻黄分布区进行封育，注重自然复壮，附加人工更新，天然中麻黄更新复壮是可行的。关键词:河西地区中麻黄生长发育特征影响因子泛更多还原

【Abstract】 For the natural Ephedra intermedia seedlings in Hexi region, the above-ground part grows slowly while the underground root-system grows fast in the first year; it sprouts in March of next year and its high growth and tillering branches are obviously increasing, and April to July are the key seasons for the growth. In the third year, the high growth will be impaired while the tillering branches are still increasing several folded. When natural E. intermedia of three-year-old is cut at the end of October, its tillering and high growth speeds up in the next year after cutting, and the high growth will increase continuously in the second year, however, slower than that of the first year, and tillering branches will increase several folds. In the third year, the high growth becomes slow while the tillering branches are still increasing but tend to be slow. After 3 years, with the flourish fertile growth, the nutrition growth will be in a state of alternative of new and old. At the same time, tillering propagation will be intensified and the community will be expanded.Trails on the cutting of several-year-old E. intermedia showed: under the same site condition, the natural seedlings and re-growing grasses will reach maximum of its height after 3-year growth, and its height differences are not obviously. However, the tillering No. of branches of re-growing grass after cutting the several-year-old E. intermedia is difference obviously, and the latter is more than that of seedlings. The biomass has positive relation with the regulation of nutrition growth.The comparison of nutrition growth between natural and artificial E. intermedia shows: the biological height of E. intermedia are different under different habitat while the similar height under the similar habitat. However, the biological height of artificial E. intermedia is obviously higher than that of natural one, the difference is 22-23cm. Whatever natural seedlings, artificial seedlings, natural re-growing grass, or artificial re-growing grass, the tillering No. will rapidly increase year by year within 3 years, while the tillering No. of artificial one are much more than that of natural one. That is to say, under certain site condition, the biological height is fixed, while No. of tillering branches will change to an extent. So the yield will be greatly enhanced through improving habitat condition.The 3-year-old E. intermedia seeding begins to be mature physically and has there-growing grasses begin to flower and bear fruits partly in the second year, then, its fertile potential will be gradually intensified while their nutrition growth be impaired.E. intermedia, a plant without wide leaves, has small area for photosynthesis. The lacking of nutrition during fertility stage causes the decay of most of its flowers, which is a strategy for the living plants in survival competition. However, it has great flowering potential and strong fertility. Only if the nutrition provided enough during fertility stage can raise fruit-bearing rate obviously.The plant, with well-developed root system, is a root-tillering plant. It often grows in a form of community. Among the existing propagation styles of the species, root Propagation is the main one to extend its community and seeds can establish new communities. In a favorable habitat, with the root system expand, more tillering seedlings sprouting and the community domain will be expanded. At this time, the productivity of the community is much high and its ability of survival competition is strong, thus, plant species will be reduced. However, if the habitat is worsened, its community will become decay and other species will invade into the community.E intermedia in Hexi corridor is distributed in the 17 counties which is to the east of Jiuquan and to the west of Huanghe river. The east part of Hexi corridor, with the dominated soil of sand loam, light loam, loam and sandy soil, is the main area where natural E. intermedia is distributed and produced. The more to the west. The habitat becomes worse with thin soil and exposed sandy更多还原