Roadside verges and cemeteries: Comparative analysis of anthropogenic orchid habitats in the Eastern Mediterranean

Several important habitats have become threatened in the last few centuries in the Mediterranean Basin due to major changes adopted in land‐use practices. The consequent loss of natural and seminatural orchid habitats leads to the appreciation of small anthropogenic habitats, such as cemeteries and roadside verges. Colonization of cemeteries and roadside verges by orchids has long been known, but no study to date compared the suitability of these two anthropogenic habitats for orchids. Therefore, in this paper our aim was to survey cemeteries and roadside verges and to compare these two habitats regarding their role in conserving Mediterranean terrestrial orchids. We conducted field surveys in three Mediterranean islands, Cyprus, Crete, and Lesbos, where both cemeteries and roadside verges were sampled on a geographically representative scale. We found a total of almost 7,000 orchid individuals, belonging to 77 species in the two anthropogenic habitat types. Roadside verges hosted significantly more individuals than cemeteries in Crete and Lesbos, and significantly more species across all three islands. Our results suggest that although cemeteries have a great potential conservation value in other parts of the world, intensive maintenance practices that characterized cemeteries in these three islands renders them unable to sustain valuable plant communities. On the other hand, roadside verges play a prominent role in the conservation of Mediterranean orchids in Cyprus and Greece. The pioneer status of roadside verges facilitates their fast colonization, while roads serve as ecological corridors in fragmented landscapes.     

Host tree utilization by epiphytic orchids in different land-use intensities in Kathmandu Valley, Nepal

We studied the influence of site conditions on epiphytic orchids under a subtropical climate in the Kathmandu Valley, Nepal. We analysed 96 systematically distributed grid points situated in Kathmandu Valley across a land-use intensity gradient (national park to urbanised city area). Geographical Information System (GIS) and remote sensing were used for classification of land-use types. We identified 23 species of epiphytic orchids, within 13 genera, from 42 different host tree species. Host preference is obvious for some orchid species (e.g., Dendrobium nobile), with certain tree species (e.g., Schima wallichii, Ficus religiosa) hosting more orchid species than others. The orchid Rhynchostylis retusa was the most common species found on many different host tree species across the land-use intensity gradient. Host species and host bark characteristics (e.g., rugosity, pH and exposure to wind) played a vital role for orchid distribution, with lower abundance in areas of higher impact. Under strong human impact (urban city area), F. religiosa was the dominant host tree, with large individual trees (mean diameter in breast height, dbh?=?1.3?m) providing the habitat for considerable populations of R. retusa individuals. In general, epiphytic orchids were found on larger host trees in urban areas than in areas of lower human impact. We found that some hosts are more likely to harbour orchid species, especially native host species. Older larger trees with rougher bark, low pH, exposed to wind and reduced human impact provided better habitats for orchids. We suggest these characteristics should be considered in urban planning to reduce human impact on the associated orchid epiphytic community.     

中国1,334种兰科植物就地保护状况评价

作者通过对中国543个自然保护区内兰科植物数据的分析,对我国1,334种兰科植物的就地保护状况进行了逐一评价。我们根据有记录分布保护区的数量,通过专家咨询的方式,将兰科植物就地保护水平划分为"有效保护"、"较好保护"、"一般保护"、"较少保护"、"保护状况不明"和"未予评价"6个等级。结果发现:有676种兰科植物在自然保护区内得到了不同程度的就地保护,占所评价兰科植物总数的51.9%;但有626种兰科植物保护状况不明,尚未受到就地保护,占总数的46.9%。另外有32种仅分布在香港、澳门和台湾地区,本研究中未予评价,约占总数的2.4%。根据评价结果,就兰科植物就地保护中存在的基础调查不足、受关注程度低、受保护率低等问题进行了深入的讨论,提出5条有针对性的建议对策:(1)加强兰科植物的调查监测;(2)提高兰科植物的保护级别与受关注程度;(3)进一步完善兰科自然保护区建设;(4)规范自然保护区综合科学考察;(5)定期评价我国兰科植物保护成效。     

A narrowly endemic photosynthetic orchid is non‐specific in its mycorrhizal associations

Mycorrhizal association is a common characteristic in a majority of land plants, and the survival and distribution of a species can depend on the distribution of suitable fungi in its habitat. Orchidaceae is one of the most species‐rich angiosperm families, and all orchids are fully dependent on fungi for their seed germination and some also for subsequent growth and survival. Given this obligate dependence, at least in the early growth stages, elucidating the patterns of orchid–mycorrhizal relationships is critical to orchid biology, ecology and conservation. To assess whether rarity of an orchid is determined by its specificity towards its fungal hosts, we studied the spatial and temporal variability in the host fungi associated with one of the rarest North American terrestrial orchids, Piperia yadonii. The fungal internal transcribed spacer region was amplified and sequenced by sampling roots from eight populations of P. yadonii distributed across two habitats, Pinus radiata forest and maritime chaparral, in California. Across populations and sampling years, 26 operational taxonomic units representing three fungal families, the Ceratobasidiaceae, Sebacinaceae and Tulasnellaceae, were identified. Fungi belonging to the Sebacinaceae were documented in orchid roots only at P. radiata forest sites, while those from the Ceratobasidiaceae and Tulasnellaceae occurred in both habitats. Our results indicate that orchid rarity can be unrelated to the breadth of mycorrhizal associations. Our data also show that the dominance of various fungal families in mycorrhizal plants can be influenced by habitat preferences of mycorrhizal partners.     

西双版纳片段化石灰岩森林附生兰科植物多样性研究

西双版纳石灰岩地区拥有丰富的兰科植物资源,但近年来随着橡胶树的大面积种植,使得该地区很多石灰岩森林呈片段化。为了解片段化石灰岩森林中附生兰科植物多样性状况以及片段化对附生兰科植物的影响,该研究选取了生境片段化的青岩寨和曼纳览,以及连续生境的绿石林和巴卡新寨等4个样地的29个样方进行多样性调查和对比研究。结果表明:4个石灰岩森林样共记录到附生兰科植物34属76种1 528株(丛)。通过对坡向、坡度、海拔、地形、郁闭度和森林类型等6个环境因子与附生兰科植物丰富度进行CCA分析,发现石灰岩地区附生兰科植物的分布主要受海拔和森林类型2个因素的影响,在海拔较高的青岩寨和巴卡新寨附生兰科植物物种丰富度高于低海拔的绿石林和曼纳览,而片段化对附生兰科植物的物种多样性和多度均无显著影响,这可能与片段化的历史较短有关。虽然目前来看生境片段化对石灰岩地区的附生兰科植物多样性无显著影响,但生境脆弱的石灰岩森林植被的保护对于兰科植物多样性保护则更具重要性。     

广西雅长林区野生兰科植物资源现状与保护策略

广西雅长林区野生兰科植物资源丰富,约有52属156种,其中雅长保护区几乎每座山头都有兰科植物的分布,但其种类与居群基株数量等分布不均匀,且不连续,呈现出破碎化现象,其中面积较大的局部密集分布区有16处.文中根据野生兰科植物的资源现状及生物生态学特性,针对目前兰科植物保育存在的问题,分析人畜干扰及自然条件变化等不利因素,从兰科植物维持机制角度出发,提出雅长野生兰科植物的保护应以就地保护为主、迁地保育为辅的保育措施与策略:保护区应加快建设的步伐,构建野生兰科植物种质资源基因库,同时对密集分布区在人畜干扰大的区域,优先拉设铁丝网围护,并派专人巡护,重点保护,确保野生兰科植物及基因库安全.     

European trade in Turkish Salep with special reference to Germany

The use of salep (ground orchid bulbs) has a long history in Turkey. The analysis of its trade revealed that it is still used there as medicine, drink and as binder in so- called Mara? Ice cream. Substitutes, however, increasingly enter the market. Export figures unfortunately do not distinguish between true salep and substitutes. The officially recorded Turkish export of 75 100 kg salep in 1993 almost certainly refers more to substitutes than to true salep. Major countries of destination are Germany, the Netherlands, and northern Cyprus. Drug importers in Germany have imported true salep for medicinal purposes for years, CITES documents were not applied for and not issued. Five medicines containing true salep could be identified on the German market for medicinal products. It is estimated that about 10–20 million orchid bulbs are collected annually in Turkey. Information to the impact of such a harvest on the population status on the species concerned are somehow contradictory. Recommendations are made for a better control of salep trade, for reducing the use of genuine salep and for better protection of orchid populations in Turkey.     

Wild orchid tuber collection in Iran: a wake-up call for conservation

Wild orchids are traditionally harvested as Salep and used in traditional medicine and ice-cream production in Iran. Recently however, illegal harvest of wild orchids for export appears to have grown. This study aimed to: (1) determine the diversity of harvested wild orchid species and their collection sites in Iran; and (2) study the current harvest status and trade chain and volume to estimate the total orchid plant extraction from natural populations. Field surveys of collectors and market surveys of traders were conducted to establish the diversity of collected species, to identify harvest hotspots, and to document harvesting and trade volumes. Sixteen species and subspecies from 7 genera of Orchidaceae are collected for their tubers. Based on estimates from the 2013 April to June harvest season more than 24.5 tons of fresh tubers were collected from three districts in Golestan province alone. It is estimated that this amount of tuber requires the lethal destructive harvesting of 5.5 –6.1 million orchids, with a market value of 320,000 USD. In the Tehran Bazar Salep trade during May–July 2013 was 1.9 tons of dried tubers, with estimated retail value of 310,000 USD. Current orchid collection practices in Iran, which have soared in recent years due to international demand, do not seem sustainable as all tubers are collected destructively. To preserve orchid populations, in the longterm, establishment of specific Orchid Conservation Areas and introduction of sustainable production practices, could alleviate harvesting pressure. In the midterm, development of a DNA barcoding-based molecular identification system could help to monitor and control illegal trade. In the near term, effective implementation of collection bans in excessively harvested areas and strengthening of current regulations are necessary to avoid the catastrophic effects of harvesting on orchid populations, as has been observed in Turkey.     

Genetic inference of epiphytic orchid colonization; it may only take one

Colonization of vacant habitat is a fundamental ecological process that affects the ability of species to persist and undergo range modifications in continually shifting landscapes. Thus, understanding factors that affect and limit colonization has important ecological and conservation implications. Epiphytic orchids are increasingly threatened by various factors, including anthropogenic habitat disturbance. As cleared areas (e.g. pastures) are recolonized by suitable host trees, the establishment and genetic composition of epiphytic orchid populations are likely a function of their colonization patterns. We used genetic analyses to infer the prevailing colonization pattern of the epiphytic orchid, Brassavola nodosa. Samples from three populations (i.e. individuals within a tree) from each of five pastures in the dry forest of Costa Rica were genotyped with neutral nuclear and chloroplast markers. Spatial autocorrelation and hierarchical genetic structure analyses were used to assess the relatedness of individuals within populations, among populations within pastures and among populations in different pastures. The results showed significant relatedness within populations (mean r = 0.166) and significant but lower relatedness among populations within a pasture (mean r = 0.058). Our data suggest that colonization of available habitats is by few individuals with subsequent population expansion resulting from in situ reproduction, and that individuals within a tree are not a random sample of the regional seed pool. Furthermore, populations within a pasture were likely colonized by seeds produced by founders of a neighbouring population within that pasture. These results have important ramifications for understanding conservation measures needed for this species and other epiphytic orchids.     

Distribution,habitat disturbance and pollination of the endangered orchid Broughtonia cubensis (Epidendrae: Laeliinae)

The geographical distribution, population structure and pollination ecology are key aspects in the conservation and management of rare orchids. Here, we address these aspects and the main threats affecting the endangered Cuban orchid Broughtonia cubensis. This rewardless orchid is self‐compatible, but pollinator dependent. However, seed production can be negatively affected by insect‐mediated selfing. Three species of small bee (genera Ceratina and Lasioglossum) act as pollinators. As in the case of other nectarless orchids, we detected two species of plant producing large amounts of nectar in the area, the floral morphology of which closely resembles that of B. cubensis. The simultaneous flowering of these species could positively affect the reproductive success of B. cubensis. Nonetheless, the fitness of this orchid in natural conditions is low, possibly related to strong pollen limitation. To the problems arising from reduced fitness is added the fact that its historical distribution range has been greatly reduced in recent years. Throughout this study, we have detected dramatic reductions in the population sizes, in some cases as a result of human plundering, but also as a consequence of hurricanes. Based on the results of this study, we propose some guidelines to manage and conserve this orchid. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 345–357.     

Studies of Mycorrhizal Fungi of Chinese Orchids and Their Role in Orchid Conservation in China—A Review

China has over 1,200 species of native orchids in nearly 173 genera. About one fourth of native species are of horticultural merit. Some species are of Chinese medicinal value. In fact, the demand on orchid species with high Chinese medicinal values such as Gastrodia elata, Dendrobium offcinale, along with demands on species of cultural importance, such as those in the genus of Cymbidium, is a major factor causing wild populations to diminish and in some cases, drive wild populations to the brink of extinction. These market demands have also driven studies on the role of mycorrhizal fungi in orchid seed germination, seedling and adult growth, and reproduction. Most of these mycorrhizal studies of Chinese orchids, however, are published in Chinese, some in medical journals, and thus overlooked by the mainstream orchid mycorrhizal publications. Yet some of these studies contained interesting discoveries on the nature of the mycorrhizal relationships between orchids and fungi. We present a review of some of these neglected publications. The most important discovery comes from the mycorrhizal studies on G. elata, in which the researchers concluded that those fungi species required to stimulate seed germination are different from those that facilitate the growth of G. elata beyond seedling stages. In addition, presence of the mycorrhizal fungi associated with vegetative growth of post-seedling G. elata hindered the germination of seeds. These phenomena were unreported prior to these studies. Furthermore, orchid mycorrhizal studies in China differ from the mainstream orchid studies in that many epiphytic species (in the genus of Dendrobium, as medicinal herbs) were investigated as well as terrestrial orchids (mostly in the genus Cymbidium, as traditional horticultural species). The different responses between epiphytic and terrestrial orchid seeds to fungi derived from roots suggest that epiphytic orchids may have a more general mycorrhizal relationship with fungi than do terrestrial orchid species during the seed germination stage. To date, orchid mycorrhizal research in China has had a strongly commercial purpose. We suggest that this continuing research on orchid mycorrhizal relationships are a solid foundation for further research that includes more rare and endangered taxa, and more in-situ studies to assist conservation and restoration of the endangered orchids. Knowledge on the identities and roles of mycorrhizal fungi of orchids holds one of the keys to successful restoration and sustainable use of Chinese orchids.     

Generalism in the interaction of Tulasnellaceae mycobionts with orchids characterizes a biodiversity hotspot in the tropical Andes of Southern Ecuador

Biotic interactions play an important role in the assembly and stability of communities. All orchids depend on mycobionts for early establishment, but whether individual orchid species depend on a specific or broad spectrum of mycobionts is still a matter of debate. Tulasnellaceae (Basidiomycota) is the richest and most widespread mycobiont worldwide. We assessed Tulasnellaceae richness in epiphytic and terrestrial orchids in different habitats, and evaluated the degree of generalism in orchid-Tulasnellaceae interactions and the robustness of this mutualistic system to the extinction of mycobiont partners. We sampled 114 orchid individuals including all common and rare species in 56 plots of 1 m² in 3 habitats: pristine forest, regenerating forest and a landslide site in a tropical montane rainforest in Southern Ecuador. We found 52 orchid and 29 Tulasnellaceae species. The composition of Tulasnellaceae OTUs was moderately to highly similar across habitats and between orchid growth forms. A significantly nested network architecture indicated the existence of a core of generalist Tulasnellaceae OTUs interacting with both rare and common orchids. Terrestrial and epiphytic orchids showed significant differences in robustness to the extinction of their Tulasnellaceae mycobionts. Thus, generalist mycobionts may be relevant for the preservation of hyperdiverse orchid communities in the tropics.     

广东兰科植物多样性保育现状

为了使广东省的兰科植物及其遗传多样性得到有效的保育, 保存我国重要野生植物资源, 在2017-2019年间, 采用样线和样地相结合的调查手段、专家快速评估和野外调查相结合的评估技术以及Wilcoxon符号秩检验和Friedman检验的统计方法, 对广东省自然分布的兰科植物进行了全面的调查和濒危等级评估, 并对其在广东省自然保护区中的就地保育情况和全国植物园中的迁地保育情况进行了综合分析。结果表明, 广东省分布有兰科植物80属235种, 其中广东特有种20种; 广东兰科植物受威胁物种有186种, 其中极危11种、濒危114种、易危61种; 就地保育的兰科植物有111种, 迁地保育的兰科植物有156种, 就地和迁地共同保育的兰科植物有96种, 保育的有效程度较低; 另外, 就地、迁地、就地和迁地共同保育的兰科植物之间没有体现出明显的差异, 保育工作缺乏选择性和针对性。基于此, 我们建议广东兰科植物的保育工作应重视基础数据的收集和持续的野外监测、提高保育物种的数量、优化迁地保育物种的选择性和针对性、完善迁地保育和就地保育之间的协同性, 同时也应重视立法和公众教育, 并构建广东兰科植物保育的网络系统。     

Eat your orchid and have it too: a potentially new conservation formula for Chinese epiphytic medicinal orchids

About a quarter of Chinese wild orchid species are used in traditional medicine or as health food supplements. The market demand for some species, such as those in the epiphytic genus Dendrobium, has diminished many wild populations to local extinction or dangerously small numbers. Conservation of these heavily exploited orchids currently relies on a two-pronged approach: establishing nature reserves and encouraging massive commercial cultivation in artificial settings. We argue that these measures are not sufficient to restore or maintain healthy wild populations, and augmentation and reintroduction of these species in natural forests are needed. We argue for an unconventional reintroduction approach, in which populations planted in natural forests are allowed to be sustainably harvested (restoration-friendly cultivation). Because Dendrobium orchids are epiphytic, restoration-friendly cultivation of these species will not be at the expenses of other native plants. In addition, market premiums on wild-collected medicinal plants will generate incentives for farmers who participate in restoration-friendly cultivation to preserve natural forests. With proper policy and oversight, the restoration-friendly cultivation of medicinal Dendrobium orchids will facilitate the conservation of these threatened species, encourage protection of natural forests, and benefit marginalized rural communities. Adding this restoration-friendly cultivation into the current mix of conservation approaches has the potential to turn deeply-entrenched traditional uses of orchids from a conservation challenge to a conservation success.     

Roadsides provide refuge for orchids: characteristic of the surrounding landscape

Seminatural habitats are declining throughout the world; thus, the role of small anthropogenic habitats in the preservation of plants is becoming increasingly appreciated. Here, we surveyed the orchid flora of roadside verges in five Central European countries (Austria, Hungary, Romania, Slovakia, and Slovenia) and tested how the surrounding landscape matrix affects the overall number of species and individuals, and also different functional groups of orchids. We found more than 2,000 individuals of 27 orchid species during our surveys. According to our results, the increasing coverage of agricultural and urban areas negatively affects both the number of orchid species and individuals on roadsides. Our study further suggests that differences in the surrounding habitats affect which species are found on roadsides, since the increasing coverage of grasslands or forested areas around orchid occurrences had a significant positive effect on the number of grassland or forest‐dwelling species and individuals, respectively. Most variance in orchid numerosity and diversity was explained by the cover of the suitable habitat types of the respective taxa in the surrounding landscape of the sampling points. This highlights the importance of roadsides acting as refugia for numerous species and valuable plant communities as well as in supporting biodiversity in general.     

Effects of urbanization on ground beetle assemblages (Coleoptera, Carabidae) of grassland habitats in western Canada

We pitfall-trapped carabid beetles across an urban-rural gradient in central Alberta, Canada to assess the relative contributions of landscape structure and habitat quality in explaining variation in composition of assemblages. The gradient ranged from the "urban" zone in the city of Edmonton, through a "suburban" zone just outside the city, into a "rural" zone 25–60 km east of the city. We trapped beetles at three replicated sites for each of two habitats (unmanaged grasslands and highly managed graveyards) in each of the three zones. Most of the 24 species (3162 individuals) captured were commonly associated with open habitats. Pterostichus melanarius , an introduced species, made up 80% of the total catch. Carabid assemblages of grasslands and graveyards were distinct, with lower species richness and lower catch rates of native, introduced and brachypterous carabids in graveyards. Graveyard assemblages also had proportionally fewer brachypterous carabid individuals (32 vs 52%) and species (20 vs 36%), suggesting that populations recruit locally from elsewhere after disturbances. Native carabids were least abundant in the urban areas. Brachypterous carabids were similarly abundant across the gradient, but more occurred in the urban zone than elsewhere (32 vs 5–10%). Samples from graveyards were characterized by lower beta diversity (variation among samples) than those from grasslands, but beta diversity was more-or-less equally variable across the gradient within habitats. The amount of unmanaged grassland habitat and the degree of urbanization significantly influence carabid assemblages, and therefore are relevant to management and conservation of urban grassland areas.     

Deceptive pollination of Dactylorhiza incarnata: an experimental test of the magnet species hypothesis

Floral deception, which mainly appears in highly evolved families such as Orchidaceae, was studied in Central Finland. In nectarless Dactylorhiza incarnata, the deceptive pollination system has been considered to function best in remote habitats such as marshes, where flowering plants attractive to pollinators are rare (remote habitats hypothesis). In contrast, the magnet-species theory predicts that a nectarless plant benefits from growing in the vicinity of nectarcontaining species. We tested these hypotheses by adding attractive, nectar-containg violets (Viola x wittrockiana) to orchid populations. The percentage of fruit set in D. incarnata was adversely affected by the violets, probably because interspecific exploitation competition for pollinators took place in favour of the violas at the expense of the orchids. This result gave no support for the magnet-species theory and supported the remote habitats hypothesis.     

Differentiation in a tropical deceptive orchid: colour polymorphism and beyond

Colour polymorphism has often been described among individuals of deceptive orchid species, and several studies have investigated reproductive success variations among colour morphs. However, whether colour morphs differed in other traits has received little attention in previous studies. Here, we report the case of a tropical deceptive orchid in Reunion Island that exhibits three different colour varieties. We investigated patterns of trait variation among colour varieties and found significant differences in floral and inflorescence morphology. Interestingly, we found that most populations included only individuals of a single variety, and that strong differences exist among varieties in spatial distribution and flowering phenology. This situation differs from previously reported cases of floral polymorphism in deceptive orchids where colour morphs co-occur and flower in the same populations. The spatio-temporal variation in flowering suggests that colour varieties have independent reproductive ecologies and are adapted to local conditions. We propose that potential variations in pollinator species abundance or diversity and the co-occurrence of nectar-producing species in the community may have driven the adaptation of each variety to its current pollination niche.     

Terrestrial orchid conservation in the age of extinction

Background

Conservation through reserves alone is now considered unlikely to achieve protection of plant species necessary to mitigate direct losses of habitat and the pervasive impact of global climate change. Assisted translocation/migration represent new challenges in the face of climate change; species, particularly orchids, will need artificial assistance to migrate from hostile environments, across ecological barriers (alienated lands such as farmlands and built infrastructure) to new climatically buffered sites. The technology and science to underpin assisted migration concepts are in their infancy for plants in general, and orchids, with their high degree of rarity, represent a particularly challenging group for which these principles need to be developed. It is likely that orchids, more than any other plant family, will be in the front-line of species to suffer large-scale extinction events as a result of climate change.

Scope

The South West Australian Floristic Region (SWAFR) is the only global biodiversity hotspot in Australia and represents an ideal test-bed for development of orchid conservation principles. Orchids comprise 6 % of all threatened vascular plants in the SWAFR, with 76 out of the 407 species known for the region having a high level of conservation risk. The situation in the SWAFR is a portent of the global crisis in terrestrial orchid conservation, and it is a region where innovative conservation solutions will be required if the impending wave of extinction is to be averted. Major threatening processes are varied, and include land clearance, salinity, burning, weed encroachment, disease and pests. This is compounded by highly specialized pollinators (locally endemic native invertebrates) and, in the most threatened groups such as hammer orchids (Drakaea) and spider orchids (Caladenia), high levels of mycorrhizal specialization. Management and development of effective conservation strategies for SWAFR orchids require a wide range of integrated scientific approaches to mitigate impacts that directly influence ecological traits critical for survival.

Conclusions

In response to threats to orchid species, integrated conservation approaches have been adopted (including ex situ and translocation principles) in the SWAFR with the result that a significant, multidisciplinary approach is under development to facilitate conservation of some of the most threatened taxa and build expertise to carry out assisted migration to new sites. Here the past two decades of orchid conservation research in the SWAFR and the role of research-based approaches for managing effective orchid conservation in a global biodiversity hotspot are reviewed.Key words: Orchids, pollination, mycorrhiza, integrated conservation, terrestrial, threats, ex situ conservation, in situ conservation