永瓣藤的分布现状及其保护

本文从自然环境、分布特征、种群数量和种群繁殖等方面研究了我国珍稀特有植物永瓣藤（Monimopetalum chinense）的分布和保护现状, 并从引种栽培、种子繁殖和无性繁殖等方面总结了近年来对永瓣藤进行迁地保存的初步研究结果, 最后提出了相应的保护建议。     

永瓣藤的营养繁殖

对中国稀有濒危植物永瓣藤（ＭｏｎｉｍｏｐｅｔａｌｕｍｃｈｉｎｅｎｓｅＲｅｈｄ．）的自然营养繁殖特性进行了调查,并进行了迁地保存及人工营养繁殖试验,结果表明：（１）永瓣藤在自然生境中主要靠营养繁殖来维持种群生存,但受其生境郁闭度的影响,繁殖率较低。（２）人工扦插繁殖是永瓣藤生物多样性迁地保存的有效方法。（３）生根剂处理能提高扦插繁殖率,尤以ＡＢＴ１的效果最佳。（４）压条繁殖是一种培育大苗的可靠方法,但有一定的局限性。     

湖北新记录属植物永瓣藤种群现状及其保护

永瓣藤（ＭｏｎｉｍｏｐｅｔａｌｕｍｃｈｉｎｅｎｓｅＲｅｈｄ．）为湖北省种子植物区系新记录属、种,是中国二级保护植物。通山县分布的永瓣藤为次生杉、竹、阔混交林内的伴生成分,群落生活型谱以常绿高位芽植物为主,种群空间分布格局为集群型。其生态适应为明显的偏酸性和一定的耐荫性。永瓣藤种群虽规模小,但具明显的增长型特征,有发展潜力。文中对永瓣藤生物多样性保护提出了具体的建议     

中国稀危植物永瓣藤生态学特征研究

永瓣藤（ＭｏｎｉｍｏｐｅｔａｌｕｍｃｈｉｎｅｎｓｅＲｅｈｄ．）是卫矛科（Ｃｅｌａｓｔｒａｃｅａｅ）的一个中国特有单型属植物,被列为国家二级稀有濒危保护树种［３,４］。对其生态学基本特征和致濒生态因素的研究有着极为重要的意义,是进行生物多样性保护及恢...     

濒危植物永瓣藤所在群落物种多样性初步研究

永瓣藤(Monimopetalum chinense)是卫矛科(Celastraceae)的一个中国特有单型属植物,被列为国家二级稀有濒危保护物种。以11个样地调查资料为基础,从物种丰富度指数、物种多样性指数和均匀度指数等方面对濒危植物永瓣藤所在群落物种多样性进行了分析。结果表明:永瓣藤所在群落物种多样性较高,植物群落结构复杂,物种丰富;从平均值来看,物种丰富度指数和物种多样性指数灌木层>草本层>乔木层,物种均匀度指数草本层>灌木层>乔木层;乔木层物种贫乏,物种多样性较低,优势树种突出;永瓣藤受人类活动干扰较大,森林的乱砍滥伐和旅游的不合理开发给该物种带来严重的威胁。     

濒危植物永瓣藤的种群结构及与环境的关系

基于相邻格子法调查资料,分析了安徽省南部山区——祁门县棕里村次生灌丛、毛竹林、杉木林和马尾松林4种类型群落中永瓣藤种群的基径、结构以及环境因子对其种群特征的影响.结果表明：不同群落中永瓣藤种群的平均基径依次为毛竹林（10.5mm）〉马尾松林（9.1mm）〉杉木林（7.2mm）〉次生灌丛（7.0mm）,其中次生灌丛、杉木林与毛竹林、马尾松林之间的差异均达到显著水平（P〈0.05）.不同群落中永瓣藤种群的结构有一定差异,次生灌丛和马尾松林群落的径级呈非典型的金字塔型分布,为稳定型种群;毛竹林群落属于纺锤形,以中等级别个体最多,种群处于衰退的早期阶段;杉木林群落属于典型金字塔型,永瓣藤幼苗数量最多.棕里村永瓣藤种群的存活曲线属于DeeveyⅡ,为增长型种群,未出现衰退迹象.永瓣藤适于生长在海拔低、土壤含水量和有机质含量高、坡度缓和、乔木层盖度较高的生境中,频繁的人为干扰将对其种群更新产生不良影响.最后就有关永瓣藤的保护提出了一些建议.     

中国-日本濒危种子植物对比研究

IUCN为全球濒危野生动植物所设立的等级和评价标准已被多个国家采用,也是国家和地区间进行濒危植物对比研究的基础。作者结合植物地理分布,根据中、日物种红色名录,对比分析两国野生种子植物的濒危程度和区系组成。研究发现：（1）中国红色名录中濒危植物的种类占其所有野生种子植物的比例显著低于日本,但裸子植物的濒危程度却极其显著地高于日本;（2）部分水生植物科未列入中国红色名录,但在日本已受到严重威胁;（3）中国红色名录中出现的世界分布属显著少于日本：（4）两国濒危植物中有大量共有种、姊妹种或近缘种。最后作者建议：（1）对水生植物的濒危状况展开全面调查;（2）加强对中日共有植物成分的研究;（3）借鉴日本经验,在中国开展植物群落水平上的调查,对红色名录进行补充。     

我国特有珍稀植物翅果油树濒危原因分析

翅果油树是我国特有种,为国家2级珍稀濒危保护植物,主要分布于山西南部的低山和丘陵区以及陕西秦岭北麓的户县。翅果油树分布区的生态环境特征是：热量充足,降水量较少,立地条件较差。翅果油树濒危的主要原因有（1）果实形态结构特殊,不利于传播和萌发,（2）果实结实率较低,（3）种子寿命短,发芽率低,（4）翅果油树幼苗缺乏竞争力和（5）人力破坏严重。此外,针对翅果油树的濒危现状和原因,还提出了科学保护对策。     

濒危植物南方红豆杉濒危原因分析

南方红豆杉是我国第三纪孑遗特有树种,为国家1级濒危保护植物,主要分布于在长江流域、南岭山脉以及广东、广西、江西、河南、陕西、甘肃、台湾和山西等省（区）的山地。南方红豆杉分布区的生态环境特征是：热量充足,温暖潮湿。南方红豆杉濒危的主要原因有：（1）种子产生量少,萌发率和幼苗成活率较低（2）种群缺乏较强的竞争力,（3）地理分布的局限性,（4）对生境要求的特殊性和（5）人为破坏严重。此外,针对南方红豆杉濒危现状和原因,还提出了科学保护和可持续利用的对策。     

附子化学成分和药理作用研究进展

长柱红山茶、美丽红山茶、贵州红山茶、皱叶瘤果茶和小黄花茶是颇具经济价值的稀有濒危植物,局部分布于贵州高原亚地区（ⅢD10 d）常绿阔叶林和常绿落叶阔叶混交林中。针对其物种濒危以及种子繁殖困难等问题,该研究对其种子生物学特性进行了分析。结果表明：（1）长柱红山茶千粒重最大（3 289.70 g）、发芽率最高（81.67%）,贵州红山茶千粒重最小（786.33 g）、发芽率最低（46.00%）;（2）小黄花茶含水率最高(48.85%),长柱红山茶含水率最低（39.52%）;（3）长柱红山茶生活力最大（98.33%）,皱叶瘤果茶生活力最小（63.33%）;（4）5种供试山茶种子的千粒重与生活力、发芽率、发芽势、发芽指数呈极显著正相关（R≥0.772,P＜0.01）,种子生活力与发芽率和发芽势呈极显著正相关（R≥0.738,P＜0.01）、与发芽指数呈显著正相关（R=0.532,P＜0.05）。以上结果说明,种皮较坚硬而不易吸水萌发,种子遭遇动物摄食和病虫侵蚀损耗而不利于种群繁衍是其物种濒危的重要原因。该研究结果为其植物资源的保护和利用提供了参考。     

Species introduction through seeds from an old,species‐rich hay meadow: Effects of management

Abstract. A local seed mixture from plants growing in a species‐rich, traditionally managed hay meadow site at Varaldsoy, Hardanger, western Norway, where many endangered hay meadow species of the region are growing, was sown in a newly harrowed experimental field 1 km from the source meadow in order to increase the habitat area for the endangered species. Of 25 endangered species recorded in the source meadow, only one (Holcus lanatus) was present in the target meadow. After sowing, 16 of the endangered species in addition to Holcus lanatus were recorded in the new site. Six species were only present in sown plots and seven others were more frequent there, while three species might have arrived by chance or originated from the seed bank. Replacing the traditional management regime, including one late cut and grazing in spring and in autumn, with three cutting times and the creation of gaps in the sward, resulted in a higher number of endangered species in plots which were only cut, possibly because the grazing was too intensive in the small enclosures.     

Conservation technologies for safeguarding and restoring threatened flora: case studies from Eastern Australia

This paper highlights recent advances and improved scientific understanding of conservation technologies through selected case studies on threatened plant species indigenous to Eastern Australia. This includes investigations into seed desiccation, storage responses and cryopreservation in rainforest species, particularly the socio-economically important Australian native Citrus spp., Davidsonia spp. (Davidson’s plum) and Syzygium spp. This work also (1) increases our understanding of ecological correlates of seed desiccation sensitivity for predictive use and (2) improves restoration practice through better understanding of seed storage and germination requirements. The use of in vitro conservation technologies in support of conservation actions for endangered species is outlined in case studies on Wollemia nobilis (Wollemi pine), epiphytic and terrestrial orchid species, and an endangered fern species.     

红皮糙果茶种子生活力测定与发芽试验

选取饱满有光泽的红皮糙果茶Camellia crapnelliana种子,进行种子贮存生活力测定、种子发芽试验及种皮解剖结构观察等研究,就种子繁殖探讨其濒危原因。结果表明,有利于保持种子生活力的贮存方式为：4 ℃贮存>常温贮存>－10 ℃贮存;种子发芽试验中,采用不同浓度赤霉素(GA₃)、吲哚丁酸(IBA)和不同温度温水处理,种子发芽率均不高,最高为40%;不同因素对种子发芽的影响不同,种子发芽最佳处理为800 mg·L^-1GA₃浸泡6 h;种皮解剖结构观察到红皮糙果茶种皮坚硬,由栓化壁和骨状石细胞组成,内、外部石细胞垂直交错排列,这可能是造成种子萌发困难的机械阻碍原因。     

Seed preferences by rodents in the agri‐environment and implications for biological weed control

Post‐dispersal seed predation and endozoochorous seed dispersal are two antagonistic processes in relation to plant recruitment, but rely on similar preconditions such as feeding behavior of seed consumers and seed traits. In agricultural landscapes, rodents are considered important seed predators, thereby potentially providing regulating ecosystem services in terms of biological weed control. However, their potential to disperse seeds endozoochorously is largely unknown. We exposed seeds of arable plant species with different seed traits (seed weight, nutrient content) and different Red List status in an experimental rye field and assessed seed removal by rodents. In a complementary laboratory experiment, consumption rates, feeding preferences, and potential endozoochory by two vole species (Microtus arvalis and Myodes glareolus) were tested. Seed consumption by rodents after 24 h was 35% in the field and 90% in the laboratory. Both vole species preferred nutrient‐rich over nutrient‐poor seeds and M. glareolus further preferred light over heavy seeds and seeds of common over those of endangered plants. Endozoochory by voles could be neglected for all tested plant species as no seeds germinated, and only few intact seeds could be retrieved from feces. Synthesis and applications. Our results suggest that voles can provide regulating services in agricultural landscapes by depleting the seed shadow of weeds, rather than facilitating plant recruitment by endozoochory. In the laboratory, endangered arable plants were less preferred by voles than noxious weeds, and thus, our results provide implications for seed choice in restoration approaches. However, other factors such as seed and predator densities need to be taken into account to reliably predict the impact of rodents on the seed fate of arable plants.     

Use of biotechnologies for the conservation of plant biodiversity

In vitro techniques are very useful for conserving plant biodiversity, including (a) genetic resources of recalcitrant seed and vegetatively propagated species, (b) rare and endangered plant species and (c) biotechnology products such as elite genotypes and genetically engineered material. Explants from recalcitrant seed and vegetatively propagated species can be efficiently collected under field conditions using in vitro techniques. In vitro culture techniques ensure the production and rapid multiplication of disease-free material. Medium-term conservation is achieved by reducing growth of plant material, thus increasing intervals between subcultures. For long-term conservation, cryopreservation (liquid nitrogen, −196°C) allows storing plant material without modification or alteration for extended periods, protected from contaminations and with limited maintenance. Slow growth storage protocols are routinely employed for a large number of species, including numerous endangered plants, from temperate and tropical origin. Cryopreservation is well advanced for vegetatively propagated species, and techniques are ready for large-scale experimentation in an increasing number of cases. Research is much less advanced for recalcitrant species due to their seed characteristics, viz., very high sensitivity to desiccation, structural complexity and heterogeneity in terms of developmental stage and water content at maturity. However, various technical approaches should be explored to develop cryopreservation techniques for a larger number of recalcitrant seed species. A range of analytical techniques are available, which allow understanding physical and biological processes taking place in explants during cryopreservation. These techniques are extremely useful to assist in the development of cryopreservation protocols. In comparison with crop species, only limited research has been performed on cryopreservation of rare and endangered species. Even though routine use of cryopreservation is still limited, an increasing number of examples where cryopreservation is used on a large scale can be found both in genebanks for crops and in botanical gardens for endangered species.     

Genetic differentiation of three endangered wild roses in northeastern Germany: Rosa inodora Fries, Rosa sherardii Davies and Rosa subcollina (H. Christ) Keller

Because of increased interest in the use of local provenances for restoration or landscaping projects, information about the genetic differentiation of plant species is required to delineate provenances for seed collection. To obtain information about population distinctiveness of endangered Rosa species occurring in Brandenburg (northeast Germany), we investigated the genetic differentiation of Rosa inodora, R. sherardii and R. subcollina using RAPD markers. All three species were uncommon in our study region. Φ-statistics, estimated by amova, revealed a low interpopulation differentiation for R. inodora (Φ(PT) = 0.19, P < 0.0001) and higher values for R. sherardii and R. subcollina (Φ(PT) = 0.29 and 0.30, P < 0.0001). UPGMA dendrograms and NMDS showed clear spatial differentiation for all species and a correlation between geographic and genetic distances. Due to predominantly high values of genetic differentiation and spatial patterns of ordination, we suggest small provenance regions for endangered Rosa species for seed collection.     

Towards integrated conservation of Australian endangered plants—the Western Australian model

Four percent of the Australian flora is rare and endangered with over 100 taxa presumed extinct. Western Australia contains a large proportion of the endangered flora of Australia with 238 taxa in a critical state of conservation and 70 species presumed extinct. Kings Park and Botanic Garden in south-west Australia is responsible for developing specialized collections of rare and endangered indigenous flora. Macro-and micropropagation procedures are used including conventional cutting and seed propagation, grafting and in thein vitro programme whole seeds (asymbiotic and symbiotic germination), excised seed embryos, shoot apices and inflorescence sections. Wherever possible explants are collected from major provenances of the species and a wide cross section of a species population. Although many of the rare flora of Western Australia are now in theex situ collection maintained by Kings Park and Botanic Garden attempts are being made to develop slow growth storage forin vitro cultures and cryostorage. Trial recovery programmes have commenced with a number of species including the rare and endangered Purdie's donkey orchid (Diuris purdiei). Results of these recovery programmes will guide future efforts in conserving and recovering rare Australian species.     

环境因素对伞形科两种植物种子萌发的影响

种子萌发模式是植物生活史策略中的一个主要特征。研究了环境因素对伞形科濒危植物明党参 (Changium smyrnioidesWolff)和非濒危植物峨参 (Anthriscussylvestris Hoffm.)种子萌发特性的影响。结果表明 ,温度是影响明党参和峨参这类冬性植物种子萌发的主要因素。两物种的种子萌发温度范围是 5～ 15℃ ,明党参种子的最适萌发温度是 10℃ ,峨参是 5℃ ,两物种在15℃时萌发率均已受抑制 ,到 18℃时几乎不萌发。两种植物种子的萌发率与温度显著负相关。两种植物种子在光照和黑暗条件下萌发率差异很小 ,均是中性种子。明党参种子在干燥条件下比峨参种子更容易失去活力 ,其种子的适宜含水量 (5 .9%～6 .4 % )比峨参 (<3.7% )高。种子质量好、萌发率高但种子产量低也是濒危植物种群更新的一个薄弱环节。     

Scanning Electron Microscopic Studies on Seed Coat Patterns of Five Endangered Himalayan Species of Meconopsis (Papaveraceae)

Scanning electron microscopic studies of seed coat patternswere carried out on 16 populations of the endangered genus Meconopsis,the Himalayan poppy. Two different types of testa can be distinguishedin the five species of Meconopsis (M. horridula, M. paniculata,M. simplicifolia, M. sinuata, M. villosa ) investigated: (a)rugose, and (b) reticulate. The results indicate the absenceof intra- and inter-population variation in all five speciesof Meconopsis. However, seed coat patterns show a marked inter-specificdifference suggesting that they are species-specific.Copyright1995, 1999 Academic Press Himalayan poppy, Meconopsis horridula, Meconopsis paniculata, Meconopsis simplicifolia, Meconopsis sinuata, Meconopsis villosa, endangered species, seed coat patterns, scanning electron microscopy     

Assessing soil seed bank persistence in flood‐meadows: The search for reliable traits

Abstract. To assess seed bank persistence of target species in endangered flood‐meadows (alliances Cnidion and Molinion), we investigated established vegetation and soil seed bank of 46 plots for 3 yr and 2 yr, respectively. As traits of seed persistence we calculated various continuous indices that refer to the frequency and abundance of species in above‐ground vegetation and at different soil depths. Furthermore, we tested the significance and soundness of easily observed traits such as maximum seed density per plot and seed attributes (mass, size and shape) as predictors of soil seed bank features. In linear regression, SAI, the seed accumulation index, showed the best agreement (R²= 0.64) with the seed longevity index that was derived from the database by Thompson et al. (1997) for a set of 115 species. The second best predictor (R²= 0.39) of the seed longevity index was maximum seed density per plot in the lower soil layer (5–10 cm). Depth distribution indices and seed attributes showed weaker but still significant relations. The dynamic character of flood‐meadows was reflected by a large proportion of species with a strong tendency to accumulate seeds in the soil relative to their importance in above‐ground vegetation. Most of these species have a ruderal strategy, exploiting gaps after flood disturbances, while the dominants of flood‐meadows tended to have short‐lived seed banks. Compared to other grassland types, a relatively large proportion of rare and endangered target species can be expected to form long‐term persistent seed banks. However, only under marginal conditions that facilitate seed survival in the soil (e.g. fallow) are these persistent seed banks likely to contribute to restoration. We conclude that easily observed traits of persistence such as seed weight, size and shape do not meet the accuracy needed in scientific and practical applications. Thus, there is a crucial demand for further seed bank studies in poorly investigated habitats and of rare species.