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1.
郑明清  郑元润  姜联合 《生态学报》2006,26(8):2474-2484
飞播固沙作为一项快速而有效的现代化治沙措施,已成为毛乌素沙地植被恢复与重建的重要手段。但此项技术仍存在一些问题,如飞播后成苗率较低等。以毛乌素沙地优势植物柠条(Caragana korshinskii)、羊柴(Hedysarum laeve)、油蒿(Artemisia ordosica)与籽蒿(Artemisia sphaerocephala)为研究对象,人工控制7个沙埋深度和9个水分梯度,研究4种植物种子萌发和幼苗出土对沙埋和单次供水的响应,阐明多大的单次降雨才能保证种子萌发与幼苗出土及出土幼苗的维持时间。结果表明,对于柠条和羊柴质量相对较大的种子而言.种子主要在供水量10.20mm,埋藏深度为0.5.2cm的条件下出苗,但在埋藏深度为5cm时这两个物种仍有少量种子能够出苗;而对于油蒿和籽蒿质量相对较小的种子而言,种子主要在供水量10.20mm,埋藏深度为0.5cm时出苗,当埋藏深度为1.5cm和2cm时不能顺利出苗。沙埋深度0.5cm条件下,4个物种具有最高的出苗率和出苗速率。在试验期内(30d),柠条、羊柴和油蒿出土幼苗分别在单次供水量为5、7.5mm和7.5mm时全部死亡,在单次供水量高于15mm时4个种的出土幼苗死亡率大多低于50%,且随供水量的增加出土幼苗死亡率降低。结合毛乌素沙地降雨特点与本次实验结果,0.5cm的沙埋及7.5mm以上的单次降雨是上述4种植物自然条件下出苗较好的重要条件。  相似文献   

2.
Four dominant psammophyte species are air-seeded in attempts to revegetate the Mu Us sandy land in Inner Mongolia, but seedling emergence is low. This study sought to clarify the behaviour of seedling emergence under different water supply and sand burial regimes to improve the technology of air seeding. Seeds were buried in sand at depths of 0, 0.5, 1, 1.5, 2, 3 and 5 cm and supplied one time with 2.5, 5, 7.5, 10, 15, 20, 30 or 40 mm of water or with 2.5 mm once every 3 days for 30 days. Our study showed that a 0.5-cm burial depth and under 10- to 20-mm single-watering regimes resulted in highest seedling emergence percentage and rate of these four species. All emerged seedlings of Caragana korshinskii , Hedysarum laeve and Artemisia ordosica died under 2.5, 5 and 7.5 mm of watering, respectively, but seedling mortality was <50% when the single-watering regime was >10 mm. In the field, germination of the four species increased from the top of the dune to the middle of the leeward side and then to the bottom. Based on precipitation pattern in the Mu Us sandy land, our study indicates that 0.5-cm burial depth and a single-watering regime of >7.5 mm is the threshold condition for seedling emergence.  相似文献   

3.
 羊柴 (Hedysarum leave)、柠条 (Caragana korshinskii)、籽蒿 (Artemisia sphaerocephala)与油蒿 (Artemisia ordosica)为鄂尔多斯高原广泛分布的植物种,也是该地区飞播选用的主要植物种。由于飞播为鄂尔多斯高原植被恢复的重要手段,而飞播后植物种子的出苗率与土壤水分及沙埋密切相关。因此,上述植物种子萌发与出苗对水分和沙埋反应的研究对当地退化生态系统的恢复具有重要意义。通过温室控制实验,对4种植物萌发特性及出苗与水分和沙埋深度的关系进行研究,阐明了种子萌发最适合的水分条件和沙埋深度。结果表明,4种植物种子萌发与出苗最适宜的供水量都接近于当地种子萌发时期的平均降水量, 最适宜的沙埋深度为0.5~1 cm, 过多的水分和过深的沙埋会降低种子萌发与出苗,反映了4种植物对沙区环境的生态适应。4种植物最适宜的供水量均为123 ml,羊柴、柠条、籽蒿和油蒿的最适沙埋深度分别为:0.5、1.0、0.5和0.5 cm。根据实验结果及当地气候特点,鄂尔多斯地区的飞播时间应由6月初提前至5月中下旬,以提高飞播植物的出苗率。  相似文献   

4.
沙埋对六种沙生植物种子萌发和幼苗出土的影响   总被引:20,自引:1,他引:19  
研究了沙埋对科尔沁沙地6种优势植物的种子萌发和幼苗出土的影响.进行0.2、4、6、8、10和12cm等7个深度沙埋处理.结果表明,在不同沙埋处理时,沙蓬萌发差异显著。而差不嘎蒿2锄埋深与其他埋深的发芽差异显著,其他4种植物0cm埋深与其他埋深的发芽差异显著;沙埋对所有植物幼苗出土均有显著影响,埋深增加,出苗率减小;繁殖体大的物种与繁殖体小的物种相比,能从更深沙层中出苗,幼苗出土最大深度排序为苦参>东北木蓼≥沙蓬>山竹子>雾冰藜>差不嘎蒿.  相似文献   

5.
李文婷  张超  王飞  郑明清  郑元润  张峰 《生态学报》2010,30(5):1192-1199
沙埋与水分是影响毛乌素沙地植物存活、生长的关键因子。通过沙埋与供水的野外控制实验,研究了毛乌素沙地重要物种柠条(Caragana korshinskii)与羊柴(Hedysarum laeve)幼苗存活及生长对沙埋和供水的反应。结果表明:适量的沙埋(0.25H-0.50H沙埋,H为苗高)与供水(柠条50mm/月,羊柴75mm/月)可以促进幼苗生长,过量的沙埋与供水则会抑制生长甚至导致幼苗死亡。柠条幼苗在50mm/月供水,0.25H、0.50H沙埋,羊柴幼苗在75mm/月供水,0.25H、0.50H沙埋下具有较高的相对生长速率和净同化速率;幼苗在1.0H和1.25H沙埋下全部死亡。供水量较小、沙埋较浅时,两种植物根冠比均较高;当供水量最大时,柠条幼苗根冠比在沙埋最深和没有沙埋时较大,而羊柴幼苗根冠比仍在没有沙埋时最高。  相似文献   

6.
《植物生态学报》2013,37(9):830
Aims Our objectives were to determine effects of sand burial on growth and physiological response in psammophytes and to compare differences in abilities and mechanisms of different psammophytes to resist sand burial. We examined changes in survival rate, plant height, osmotic regulation substances contents, protective enzymes activity and membrane permeability of Agriophyllum squarrosum and Artemisia halodendron with different sand burial depths during 2010 in the Horqin Sand Land of Inner Mongolia.
Methods There were ten sand burial treatments: buried to 0% (CK, no burial) and 25% (A), 50% (B), 75% (C) and 100% (D) of seedling height and 2, 4, 6, 8 and 10 cm above seedlings. Every treatment consisted of four replicates. Stress physiology properties were measured 10–12 days after sand burial, and plant height and survival rate were measured in late August.
Important findings With increased sand burial depth, both survival rate and plant height of Agriophyllum squarrosum and Artemisia halodendron decreased significantly, with a greater decrease in Artemisia halodendron. The maximum depth to resist sand burial exceeded 10 and 8 cm of seedling height for Agriophyllum squarrosum and Artemisia halodendron, respectively. The two psammophytes showed no water stress under sand burial stress. Decreased photosynthetic area and increased difficulties to emerge from the soil were the main factors that inhibited the survival and growth of the psammophyte seedlings. With increased depth of sand burial, malonaldehyde content increased significantly for Agriophyllum squarrosum and decreased significantly for Artemisia halodendron. The increased magnitude of membrane permeability was significantly lower in Artemisia halodendron. Injury of the cell membrane was the main physiological mechanism to decrease survival rate and inhibit growth in the psammophyte seedlings under sand-burial stress. Also, lighter membrane damage was the main physiologicalmechanism that gave Agriophyllum squarrosum stronger resistance to sand burial. Although both species reduce plant cell membrane damage and degree of cytoplasm leakage by increasing peroxidase activity and proline content under sand burial stress, superoxide dismutase also showed an important coordinating role for Agriophyllum squarrosum that makes its enzymatic system more effective in the protection of cell membrane from stress injury.  相似文献   

7.
在库布齐沙漠东段选取人工油蒿+杨柴半灌木混交林、人工柠条锦鸡儿灌木林和人工沙柳灌木林3种人工固沙灌木林为对象,以流动沙地为对照,研究了不同人工固沙灌木林土壤微生物生物量碳和氮、土壤微生物数量、土壤养分变化特征及其相互间的关系,并运用综合指数法对不同人工固沙灌木林的土壤恢复效果进行评价.结果表明: 与流动沙地相比,3种人工固沙灌木林土壤有机质、全氮、全磷、速效氮、速效磷含量均有不同程度的提高,表现为油蒿+杨柴林地>柠条锦鸡儿林地>沙柳林地,且均随土层加深而依次降低;3种人工固沙灌木林土壤微生物数量、微生物生物量碳和氮均较流动沙地有不同程度的提高,油蒿+杨柴林地土壤微生物生物量碳氮和细菌相对数量高于柠条锦鸡儿林地和沙柳林地,而真菌与放线菌相对数量则表现为柠条锦鸡儿林地>沙柳林地>油蒿+杨柴林地;影响3种人工固沙灌木林土壤细菌相对数量、微生物生物量碳和氮的因素是土壤有机质、全氮、全磷、速效氮、速效磷含量及C/N,而放线菌、真菌相对数量主要受土壤全磷、速效氮和速效磷含量的影响;不同人工固沙灌木林土壤质量排序为:油蒿+杨柴林地>柠条锦鸡儿林地>沙柳林地>流动沙地,表明不同人工固沙灌木林的建植均能提高沙漠土壤质量,其中营造油蒿+杨柴半灌木混交林对提高土壤综合质量效果最好.  相似文献   

8.
本文从沙漠植物更新生态的角度,试验分析了油蒿、柠条和花棒种子萌发的条件,明确了三种灌木的累积发芽率与一次降雨量、连续阴天天数和种子埋藏深度之间的相依关系,阐明了它们适应沙漠严酷生境的各项特点的生态对策。  相似文献   

9.
几种旱生灌木种子萌发对干旱胁迫的响应   总被引:60,自引:5,他引:55  
以不同渗透势的PEG(6 0 0 0 )溶液 (- 0 .3~ - 2 .7MPa)为模拟干旱胁迫条件 ,研究了柠条 (Caraganakorshinskii)、花棒 (Hedysarumscoparium)和白沙蒿 (Artemisiasphaerocephala)种子发芽、幼苗生长和累积吸水率对干旱胁迫的响应 ,讨论了参试种子发芽特性、初生根长度与幼苗建植成活率的关系 .结果表明 ,干旱胁迫下柠条发芽率最高 ,其次为花棒 ,白沙蒿最低 . - 0 .3~ - 0 .6MPa渗透势下白沙蒿发芽 10d的初生根长度显著大于花棒和柠条 (P <0 .0 5 ) ,三者的测量值依次为 7.9、4 .5和 3.1cm .干旱胁迫条件下参试种子发芽率与种子 72h累积吸水率均呈极显著的正相关 (P <0 .0 1) .  相似文献   

10.
不同风沙条件对几种植物生态生理特征的影响   总被引:17,自引:1,他引:16       下载免费PDF全文
 在野外风洞条件下,就不同风况的风沙胁迫对几种固沙植物生态生理特征的影响进行了实验研究。实验采用了沙坡头地区的野外植物和盆栽植物。在不同风速(5.9 m·s-1, 7.9 m·s-1, 9.9 m·s-1,14 m·s-1, 10 m·s-1,15 m·s-1, 20 m·s-1)和吹袭时间间隔(2 d, 4 d, 9 d)下测定了植物3个生理生态参数的变化。实验结果表明:1)净风和风沙流胁迫均可使植物的净光合速率(Pn)降低,蒸腾速率(E)升高,从而导致水分利用效率(WUE)下降。净风和风沙流对植物生理生态特征的影响显著不同。同样为14 m·s-1的风速时,风沙流使植物的Pn降低40.7%,而净风使其降低了35.88%。2)吹袭的时间间隔越短,植物的净光合速率降幅越大;风沙流比净风的影响更大。在2 d, 4 d, 9 d为间隔的风沙流吹袭下,油蒿(Artemisia ordosica)的Pn分别下降了20.13%、 11.76%、 7.72%。风沙胁迫强度越大,物质积累越少,植物的高生长越慢。3)由于风沙流降低了水分利用率,从而增加了对植物的干燥作用。从总体来看,沙生植物对风沙流胁迫有一定的适应响应,实验所用灌木较草本植物有更强的抗风性。  相似文献   

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