【作者】 徐诗涛；

【导师】 陈秋波；

【作者基本信息】 海南大学 ， 作物栽培学与耕作学， 2013， 博士

【摘要】 海南岛地处热带北缘,物种分化明显,保存有丰富的热带雨林物种,对我国乃至整个东南亚植物区系研究具有重要意义。热带森林具有丰富的物种和复杂的生态系统,而热带雨林沟谷是热带山地雨林中河流水系长期冲刷形成的一个自然生态系统,属于典型特殊生境区域,有着独特多样且非地带性植物区系,是组成该区植物区系的关键地带,成为研究植物物种分化和多样性形成机制最理想的区域。多年来人们对其系统内乔灌木系统比较关注,而忽视了系统中丰富的附生植物系统。鸟巢蕨Aspleniaceae (Bird’s nest fern)是热带雨林大型附生植物,具有重要的生态功能。随着市场对鸟巢蕨的药用价值、食用价值和观赏价值的认知与需求,人们对野生鸟巢蕨资源的采集已经严重威胁到鸟巢蕨的生存。因此,需要对鸟巢蕨及其相关的热带雨林加大保护与保育,为此必须加强相关的研究。本研究通过对霸王岭和黎母山两个自然保护区内的热带沟谷雨林设立样地,以鸟巢蕨为研究对象,拟探明鸟巢蕨在海南热带沟谷雨林中附生特性,包括生态环境特点、生态位及与宿主乔木的关系；在此基础上分析鸟巢蕨在雨林生态系统中的价值,并进一步探索人工栽培鸟巢蕨的基质适应性。研究结果不仅有助于较为全面了解鸟巢蕨在热带雨林群落中的生态功能、生长特点,而且可为鸟巢蕨资源的合理开发与保护提供科学基础资料。研究结果和结论如下：(1)霸王岭与黎母山附生鸟巢蕨样地地形、地貌、植被、物种等具有较高的相似性,包括鸟巢蕨等附生物种比较丰富的原因是由于特殊沟谷环境造成了特殊生境,存在比较独立的,不受人为干扰的光、热、水、温、湿、土等高异质生境条件相互作用于中低海拔这一区域共同形成的丰富多样的沟谷雨林生态系统。鸟巢蕨偏好在沟谷雨林中600-750m海拔区域的大树上附生。(2)以两个样地物种调查数据为基础,对霸王岭和黎母山两个附生鸟巢蕨较丰富的沟谷雨林物种进行了生态位重叠和生态位宽度计测,采用TWINSPAN和DCA对两个样地的物种进行分析,划分为14个类型。结果表明,鸟巢蕨具有较宽的生态位,其附生特性使其与宿主形成偏利共生并庇护其它生物的作用,有利于丰富与维护雨林生态系统的物种多样性。(3)以海南霸王岭和黎母山保护区热带山地森林为对象,采用样地调查方法,对两地森林附生鸟巢蕨的数量、分布与宿主种类、胸径及树皮特性进行调查研究。结果表明：霸王岭地区鸟巢蕨与宿主树之间关系稳定,生存条件一般,而黎母山鸟巢蕨受干扰较少,生存状态较好,处于扩张生长状态；鸟巢蕨规格随着着生点的增高以及宿主树胸径的增大而增加；鸟巢蕨的数量和宿主树的高度和冠幅都存在着显著的中度相关性；附生鸟巢蕨与宿主有一定的选择性,与宿主大小和树皮特性的相关性不显著。(4)霸王岭沟谷雨林附生鸟巢蕨高位土研究结果表明：其根部高位土壤及林下0-10cm、1-20cm地表不同深度和位于沟谷坡顶,斜坡和谷底的不同坡度的土壤差异显著。高位土有机质达66.84%,是林地地表土壤含有的有机质的17-22倍；高位土含水量高达305%,是林地土壤的8-21倍。高位土全N、速效P、速效K均高于地表土壤,尤其是速效P是地表土壤的17-22倍,速效K是地表土壤的9-15倍,且此差异随土层深度增加而明显加大。各部分土壤pH值均较低,呈酸性,依次是坡顶>斜坡>坡底>高位土,高位土pH值最低,差异极显著。脲酶、纤维素酶和过氧化氢酶的活性均高于林中地表腐殖质,表明高位土是一种具有较高生物活性的有机土。(5)海南地区常用的栽培基质对鸟巢蕨生长的适应性研究结果表明：鸟巢蕨适宜在泥炭、火山石、椰糠和河沙混合的基质中生长。本研究的结果表明,海南岛热带沟谷雨林高温、高湿、多雨、荫蔽的环境条件是阴性鸟巢蕨生态特点中的环境特点,在同一地理单元内,决定鸟巢蕨分布格局的最重要环境因子是水分或者湿度；鸟巢蕨对附生宿主树种没有专一性,但对附生树种的高度、粗度和冠幅有偏好,对树皮没有严格要求；鸟巢蕨具有较宽的生态位；其高位土无机、有机养分丰富,能为其它生物提供栖息庇护；鸟巢蕨适宜的人工栽培基质是椰糠、火山石、河沙和泥炭土适当搭配。偏利共生并庇护其它生物是附生鸟巢蕨在热带雨林群落中与其它种间的关系特征,附生鸟巢蕨离不开结构复杂的雨林生态系统,要保育和丰富雨林生物多样性,雨林生态系统也不能没有附生鸟巢蕨这一类型的林冠附生植物,因此必须保护好鸟巢蕨及其相关的热带雨林。本研究的结果丰富了林冠植物生态学与森林群落生态学、保育生物学理论,为合理保护海南的热带雨林、合理开发利用与保护鸟巢蕨资源提供了有益的意见与参考。更多还原

【Abstract】 Located in the tropical northern rim of species differentiation, preserving the rich tropical rainforest species, Hainan Island is of great significance to China and the whole Southeast Asian flora. Tropical forests have rich species and complex ecological systems. The ravine system in the rainforest is formed to be a natural ecological system with unique diversity and azonality flora by long term erosion by rivers and waters, which is a typical special microhabitat and ideal place to study the species differentiation and diversity formation mechanism. Over the years, much attention has been paid to the shrubs and woods with ignorance to the epiphytes inside the forests.As the biggest epiphytic fern in the tropical rainforest, the bird’s nest fern(Asplenium nidus L.) Aspleniaceae plays important role in biodiverstity maintaining mechanism and attracted more attention around. With understanding and market demand for value of the bird’s nest fern as medicinal, vegetable and ornamental use, the collecting for wild ferns by people has threatened the survival of the forest as well as the fern. It is highly urgent to strengthen some study to enhance the preservation and conservation to the forest as well as the ferns. We took bird’s nest fern as the study object to emulate its habitat characteristics in the rainforest ravines, including the characteristics of the ecological environment, niche and host trees. Then we made analysis of the nutritious value as well as the value as vegetable. We further explore the suitable growing conditions by cultivation. These provided a more comprehensive understanding of the bird’s nest fern in the tropical rain forest in the position, function, growth characteristics, which also provided new theory and knowledge for tropical rainforest community ecology, canopy epiphyte ecology, ecology and resource of bird’s nest fern. We set up two plots in Bawangling Nature Reserve and Limushan Nature Reserve separately to make survey to the habitat at site, to make the nutritional ananlysis of the young leaves in the lab and to make experiments in the field and greehouse to find favorable growing conditions for extensive field plantation. Main results and conclusions are as follows.(1) The relationship between plants and conditions is one of the most essential characters of plant communities. The land form of a hilly area usually consists of various micro-landform units. The heterogeneous habitats created by spatial arrangement of those units may support richer species and more communities. Landforms are assumed to be one of the most principal and determinant factors affecting the vegetation pattern within a climatic region. In humid hilly regions, the habitats are influenced by water erosion, which varies in frequency and extent. We took Limushan and Bawangling natural reserves to set up two plots which were rich in epiphytic bird’s nest fern. According to the micro-landform theory, we classified the plots according to seven types of micro-landform units:(i) crest slope (CS);(ii) upper sideslope (US); (iii) head hollow(HH);(iv) lower sideslope (LS);(v) foot slope (FS);(vi) flood terrace(FT); and (vii) river bed (RB).Then we made analysis of survey data of epiphytic bird’s nest fern ravines in the rainforest by floristic geography, comparing the two plots of species similarity, as well as slope species characteristics in up and down slopes, and correlation of species richness with micro-landforms, the two plots distinction with contact. The results show that, the Bawangling and Limushan epiphytic bird’s nest fern-as the terrain, landforms, vegetation, species with higher similarities, including the relatively rich because of the epiphytic species of bird’s nest fern and other special valley environment special habitats independent from human disturbance, light, heat, water, temperature, humidity, soil contour heterogeneous habitat conditions interactions together form the variety in this region of the mid-to-low elevation valley rainforest ecosystem, formed a strange rainforest epiphytic bird’s nest fern main distribution is more concentrated. The characteristics of the terrain is the ups and downs of the terrain, larger changes, mainly the river, it was decided the bird’s nest fern reproductive manner closely related to water. Investigation of the distribution of the two through the bird’s nest fern valley rain forest, we can see the bird’s nest fern preferences600-750m altitude area of large trees in the ravine rain epiphytic species-rich, perennial high temperature and humidity’habitat generally similar.(2) Plant communities are classified and ordinated based on community characteristics. The amount of niche breadth and niche overlap can be good indicators of the structure and stability of the community. To understand the function and characteristics of the epiphytic bird’s nest fern in tropical rainforests, we surveyed communities with bird’s next ferns at two sites within Hainan Province in2011. Two-Way Indicator Species Analysis (TWINSPAN) and Detrended Correspondence Analysis (DCA) revealed14distinct plant communities in one hundred10m×10m quadrats, indicating that the communities were highly diverse. Bird’s nest fern has the greatest niche breadth, followed by Ervatamia officinalis Tsiang, Bischofia polycarpa and Wrightia pubescens, indicating that these species are important generalists in these communities The niche overlap of the bird’s nest fern community was found to be relatively small, indicating that the community is stable.(3) To make a survey to host trees of the bird’s nest fern in the Bawangling and Limushan ravine with rich valley rainforest species, we investigated the Bird’s Nest of fern epiphytes host tree species, height, diameter at breast height, number, combined with the growth characteristics of the bird’s nest fern, epiphytic height, leaf number, length, etc. and epiphytic index measured. The results showed that the bird’s nest fern has a certain degree of host specificity as for host tree species, diameter at breast height and height requirements. The bird’s nest fern like high temperature, high humidity, low light habitats, also like to grow at an altitude of600-750m ravine, in particular, tend to grow in the valley side of the ravine. Bird’s nest fern is not very specific to selection of the host tree, the valley humid habitats outside depends largely on a combination of factors of the host species, including the diameter at breast height, tree height, crown, bark texture, and so on. It can be said that the bird’s nest fern like tall trees, crown.smooth bark and tree fissures or wrinkles. The bird’s nest fern mainly distribute in trunk area of the tree which is in the central position of the canopy in the community, within5-10m range of hight showing aggregation distribution preference.(4) Conventional soil analysis method was adopted and quantitative and qualitative analysis were made to suspended soil from bird’s nest fern. The results showed that organic matter content is about66.84%, pH4.4, similar or above to the other indicators of the forest floor soil. Some of the indicators were even superior to the soils on the ground. Suspended soils is formed by bird’s nest fern absorbing litters from tropical rainforest specialization to soils rich in organic matter, and promoting the role of the maintenance and evolution of tropical rain forest biodiversity the rainforest matter and energy cycle.(5) In order to find the suitable media formula for the domesticated bird’s nest fern better growth in fields, some mix of media were tried to see the adapatability from epiphytic to field. The results showed that the bird’s nest fern prefers growing in the combination of cultivations as that mix of peatcoco coils,volcanic rock and sand. This could make a healthy and rapid growth of the bird’s nest fern with a favorable leaf quality.The results of present study indicated that, the tropical ravine of Hainan Island with the high temperature, high humidity, rain, shaded environment is the habitat characteristics of the bird’s nest fern. In the same geographical unit, the most important environmental factor which determines the distribution pattern of bird’s nest fern is water or moisture. The bird’s nest fern has no strict specificity to the species of epiphytic host tree, while it has preferences to the height, thickness and width of the hosts with no specificity to the barks of the hosts. The bird’s nest fern has a broad niche which indicates it employs a favorable living condition within the population of the sampled forest. The suspended soil in its roots is rich in organic and inorganic nutrient which can provide not only habitat asylum for other organisms but also nutrients for itself. One of the favorable artificial cultivation substrate for bird’s nest fern is the mixture of coco coils, volcanic rock, river sand and peat soil. Commensalism and asylum other biological is the characteristic of epiphytic bird’s nest fern in the tropical rain forest communities and other species. The epiphytic fern depends on such a rain forest ecosystem with complex structure. So it is of great need to conserve and enrich the biological diversity of the rainforest. The forest ecosystem also relies on the epiphytes of this type, therefore we must protect the nest fern as well as the tropical rainforest related. The results of this study enriches the theory of plant ecology, forest canopy community ecology, conservation biology, providing advice and reference for rational protection of the tropical forests, utilization and protection of bird’s best fern resources in Hainan island.更多还原