干旱区生态环境知识资源中心(Arid): 科尔沁沙地78种植物繁殖体重量和形状比较

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	科尔沁沙地78种植物繁殖体重量和形状比较
其他题名	A comparative study on diaspore weight and shape of 78 species in the Horqin Steppe
	闫巧玲; 刘志民; 骆永明; 王红梅
来源期刊	生态学报
ISSN	1000-0933
出版年	2004
卷号	24 期号:11 页码:2422-2429
中文摘要	研究了科尔沁沙地78种植物的繁殖体(23种为种子,55种为果实)重量和形状,其重量差别很大,最小的单粒重不足0.1 mg,最大的超过130 mg;形状差异也很大,最小的方差不足0.03,最大的超过0.18.综合本研究和以前研究的全部140种植物的研究结果,进行了分析.结果表明:①计有24种植物繁殖体单粒重小于1 mg并接近圆球形(方差小于0.09),它们可能具有持久种子库;②1年生植物(平均方差为0.070)与2年生植物(平均方差为0.129)间的形状差异显著(P<0.05),2年生植物的繁殖体更加扁、长;1年生植物也与多年生草本植物(平均方差为0.109)之间形状差异显著(P<0.05),多年生草本植物的繁殖体更加扁、长;③有55%的豆科植物、70%的藜科植物繁殖体接近圆球形(方差<0.06),所有的菊科、萝摩科植物繁殖体都很扁、长(方差>0.06).豆科植物显著比菊科、禾本科、藜科植物繁殖体的重量大(P<0.05);④繁殖体附属物在植物的传播和定居方面具有重要的作用:6种萝摩科植物和3种杨柳科植物具有绢毛,60%的菊科植物具有冠毛,6种植物有翅,8种植物有宿存花柱或宿存花萼,这些植物可能易于被风传播;54%的禾本科植物具芒,减小了传播可能;苍耳、雾冰藜、鹤虱、蒺藜、戟叶滨藜、鬼针草等植物带钩或刺,易于被动物传播;⑤11种沙生植物重量居中,其中刺沙蓬、雾冰藜具刺,沙蓬、烛台虫实繁殖体呈圆盘形,白草的繁殖体形状细长,东北木蓼、山竹子、小叶锦鸡儿、苦参的繁殖体重量大,这些植物的繁殖体因而不易被风吹动;另外2种植物差巴嘎蒿和乌丹蒿具有种子遇水分泌粘液从而粘沙增重的性能.沙生植物繁殖体的这些形态特征增大了沙生植物发芽和定居的成功率.
英文摘要	In this paper, we diaspore weight and shape of 78 species (23 seeds , 55 fruits) in the Horqin Steppe. Horqin Steppe , located in the semiarid agropastoral zone of northern China, has undergone severe desertification during the past decades with the formation of active dunes, degeneration of natural vegetation, and loss of biodiversity. The objectives of the paper arc to find out the relationships between morphological characteristics of diaspores and vegetation processes, meanwhile, to accumulate basic data for managing vegetation in the study area. Seeds were taken at the Wulanaodu region (119°39’~120°02’E, 42°29’~43°06’N, 480 m a.s.l. ) in 2003. The climate of the region is semiarid with a mean annual precipitation of around 340 mm and a mean annual temperature of 6-3 C. At present, 90% of the total land has been desertified and 70% of the meadow has become saline and sodic. Psammophil?-dominated vegetation is well developed. Plant diaspores are usually referred to as seeds, even though many of them in fact are fruits. We analyzed data on seeds and indehiscent, single-seeded fruit. Air-dried weight of 100 diaspores was measured for each replica, and five replicas were employed. Most grasses caryopses were measured with the persistent lemmas and awns with which they are normally dispersed. The achenes of Compositae were measured with pappus, and seeds of Cynanchum chinense^Salix gordejevii -.Salix mongoHca-,Salix microstachya were measured with hairs. Fruits of Bidens bipinnata, Atriplex hastata and Tribulus terrestris were measured with spine.The shape of diapores was determined by the variance of three-dimensions (length, width, height), five replicas were employed. Diapores of Gramineae (if there being awn) were measued with the persistent lemmas but without awn; those of Compositae without pappus, Bidens bipinnata and Atriplex hastata with spine. The shape variance was smaller, the diaspore was closer to sphericity. In this paper, we presented diaspore weight and shape of 78 species, but analyzed 140 species (others obtained from previous studies). Of the species examined, 24 species (accounting for 17%) had a diaspore weight less than 1 mg, and meanwhile, close to sphericity (variance less than 0.09). Previous studies have shown that morphological characteristics of diaspore are closely related to longevity of soil seed bank, thus these species might have persistent soil seed bank, and adapt to disturbance. Although diaspore weight and shape might be related to life form of plants, evident distinctions of diaspore weight of different life forms were not found. The shape difference of diaspores, however, was distinct between annuals (mean variance 0. 070) and biennials (mean variance 0. 129) (P<0. 05), and the diaspores of biennials were flatter and longer. Besides, there was an evident shape difference of diaspores between annuals and perennials (mean variance 0.109) (P<0. 05), and the diaspores of perennials were flatter and longer. So, the diaspores of annuals were closest to sphericity in comparison with biennials and perennials. Study on whether they were easier to form persistent seed bank is needed. The diaspores of 55% Leguminosae species and 70% Chenopodiaceae species were close to sphericity (variance less than 0. 06) > and all the diaspores of Compositae and Asclepiadaceae species were flat and elongated (variance more than 0. 06). The diaspore weight of Leguminosae species was evidently larger than that of Compositae, Gramineae and Chenopodiaceae species (P<0. 05). The appendages of diaspores played an important role in dispersal and establishment. 6 Asclepiadaceae species and 3 Salicaceae species had diaspores with hairs. The diaspores of 60% Compositae species had pappuses. Totally, 6 species had diaspores with wings, and 8 species with styles or calyxes. All the species with appendages might be dispersed by wind easily. The diaspores of 54% Gramineae species had awns, according to previous studies, these species were not likely to be dispersed. The diaspores of species such as Xanthium sibiricum, Bassia dasyphylla, Lappula myosatis, Tribulus terrestris, Atriplex hastata and Bidens bipinnata had hooks or spines, thus they might be dispersed by animals easily. The characteristics of diaspore weight and shape was not the only mechanism adaptive to the mobility of sand dunes, but it is one of the most important. All the psammophytes, 11 in total, had medium diaspores, some of them had appendages, and flat and elongated shapes. The diaspores of Salsola ruhtenica and Bassia dasyphylla had spine, those of Agriophyllum squarrosum and Corispermum candelabrum were disc-shaped, and those of Pennisetum centrasiaticum elongated. Besides, diaspores of some psammophytes, Atraphaxis manshurica, Hedysarum fruticosum, Caragana microphylla and Sophora flavescens were heavy, thus were not likely to be carried away by wind. Two other psammophilous species, Artemisia halodendron and A. wudanica, had the capability of excreting mucilage and holding sand upon moistening to increase weight. All of above mechanisims raised possibility of psammophytes’ germination and success of establishment on the active sand dune. Nevertheless, the investigation of diaspore dispersal and soil seed bank persistence is needed before we could fully understand the ecological significance of diaspore morphology.
中文关键词	繁殖体 ; 土壤种子库 ; 沙生植物 ; 附属物 ; 生活型 ; 传播
英文关键词	diaspore soil seed bank psammophytes appendages life form dispersal
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:1805650
来源机构	中国科学院沈阳应用生态研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/205387
作者单位	中国科学院沈阳应用生态研究所, 沈阳, 辽宁 110016, 中国
推荐引用方式 GB/T 7714	闫巧玲,刘志民,骆永明,等. 科尔沁沙地78种植物繁殖体重量和形状比较[J]. 中国科学院沈阳应用生态研究所,2004,24(11):2422-2429.
APA	闫巧玲,刘志民,骆永明,&王红梅.(2004).科尔沁沙地78种植物繁殖体重量和形状比较.生态学报,24(11),2422-2429.
MLA	闫巧玲,et al."科尔沁沙地78种植物繁殖体重量和形状比较".生态学报 24.11(2004):2422-2429.