Kadoorie Farm and Botanic Garden Corporation

Hong Kong, China

Kadoorie Farm and Botanic Garden Corporation

Hong Kong, China
SEARCH FILTERS
Time filter
Source Type

Hareesh V.S.,University of Calicut | Kumar P.,Kadoorie Farm and Botanic Garden Corporation | Sabu M.,University of Calicut
Phytotaxa | Year: 2017

Pleione arunachalensis, a new species is described from Lower Dibang Valley district of Arunachal Pradesh, North-East India. Detailed descriptions, distribution, ecology, colour photographs and key to identification for Indian Pleione is provided. © 2017 Magnolia Press.


Li J.-W.,CAS Xishuangbanna Tropical Botanical Garden | Hu A.-Q.,University of Hong Kong | Hu A.-Q.,Kadoorie Farm and Botanic Garden Corporation | Gale S.W.,Kadoorie Farm and Botanic Garden Corporation | And 2 more authors.
Phytotaxa | Year: 2017

Bulbophyllum jingdongense, a new species from South China and Laos belonging to the Cirrhopetalum alliance (Orchidaceae), is described and illustrated. It is morphologically distinct from all other known species in the alliance on account of the following diagnostic characters: pseudobulbs compressed subglobose; sepals and petals with dense, reddish-purple papillae on abaxial surfaces; lateral sepals basally connivent along their lower edges, the upper edges strongly incurved and connivent at the middle and then becoming separate again towards their incurved, horn-shaped, obtuse apex; column with a single orange-yellow gland below the stigma; and stelidia well-developed, 2.5–3 mm long, truncate at base, acuminate, merging with the column wings on each side of the column. The conservation status of B. jingdongense is assessed and taxonomic notes are provided. © 2017 Magnolia Press.


Nichol J.E.,Hong Kong Polytechnic University | Abbas S.,Hong Kong Polytechnic University | Fischer G.A.,Kadoorie Farm and Botanic Garden Corporation
Global Ecology and Conservation | Year: 2017

Landscape metrics have often been used to analyse the spatial dynamics of habitat fragmentation accompanying forest loss. However, there are few studies of the spatial dynamics of natural forest succession, especially over periods longer than the operational period of imaging satellites. This study applies spatial metrics to understand the spatial processes of a 70-year tropical secondary forest succession in Hong Kong, since World War 2. The highest rate of forest regeneration at 11% a year from 1989 to 2001 occurred when the landscape achieved greatest habitat diversity and juxtapositioning of habitat patches. This rapid regeneration occurred by infilling from remnant forest in adjacent valleys rather than by an advance along a broad forest front, and led to simplification of the landscape and declining habitat diversity. It was also accompanied by declines in species richness and abundance in regenerated forest patches. Thus both habitat and woody plant species diversity show a humped trend over the successional period as disconnected forest patches amalgamate, and shade-intolerant pioneers are shaded out by taller pioneers. From this point onwards, the birds of mixed habitats including bulbuls and hwamei known to disperse seed in the study area, may become less effective as forest patches consolidate, and only a few forest mammals remain. The observed improved connectivity within forest patches and reduced edge disturbances accompanying landscape simplification provide better conditions for dispersion within forest of light-intolerant climax species from the oldest, species-rich valley sites to the newly regenerated areas. However, in addition to the loss of forest dispersal agents, other natural dispersal agents such as gravity, flash floods and slope wash involving downward processes may be ineffective, as forest has regenerated upwards to higher elevations. Progression to a mature, biodiverse and stable forest ecosystem may depend on introduction of dispersal agents other than those which have operated over recent decades. Forest patches with high internal connectivity, indicated by high Mean radius of Gyration (MRG) and low Mean Perimeter-to-Area Ratio (MPAR) would appear to offer the best movement opportunities and least disturbance to such introductions. © 2017 The Authors


Devan-Song A.,University of Hong Kong | Martelli P.,Ocean Park Corporation | Dudgeon D.,University of Hong Kong | Crow P.,Kadoorie Farm and Botanic Garden Corporation | And 2 more authors.
Biological Conservation | Year: 2016

Translocation of ‘nuisance’ snakes is frequently employed on a large scale in densely populated areas in order to mitigate human-wildlife conflict. However, the methods used are often applied haphazardly and are rarely evaluated, especially in tropical Asia. The objective of this study was to assess the effects of long-distance translocation on the white-lipped pit viper (Trimeresurus albolabris) in South China, where they are routinely removed from urban areas or homes and translocated into national parks. Using radio telemetry, we compared the ecology and biology of ‘resident’ and ‘translocated’ snakes to determine if long-distance translocation (> 3 km) is a viable conservation option. Translocation extended the period over which predation occurred and significantly decreased survival. Translocated snakes made unidirectional movements away from points of release, yet these movements were not oriented towards points of origin and there was no evidence for homing behavior. Translocation significantly increased frequency of movements and distances moved by female snakes, but no such differences were observed for male snakes. In contrast with resident snakes, translocated snakes did not show synchrony in the onset of brumation, and translocation appeared to negatively affect reproduction in both males and females. Our results suggest that long-distance translocation is not the best management approach to handle nuisance individuals of this species. Findings of this study can be used to prescribe improvements for current strategies to deal with nuisance snakes in Hong Kong and in the region. © 2016 Elsevier Ltd


Gamisch A.,University of Salzburg | Staedler Y.M.,University of Vienna | Schonenberger J.,University of Vienna | Fischer G.A.,Kadoorie Farm and Botanic Garden Corporation | Comes H.P.,University of Salzburg
PLoS ONE | Year: 2013

Background:The rostellum, a projecting part of the gynostemium in orchid flowers, separates the anther(s) from the stigma and thus commonly prevents auto-pollination. Nonetheless, as a modified (usually distal) portion of the median stigma lobe, the rostellum has been frequently invoked of having re-gained a stigmatic function in rare cases of orchid auto-pollination. Here it is shown that a newly discovered selfing variant of Madagascan Bulbophyllum bicoloratum has evolved a modified rostellum allowing the penetration of pollen tubes from in situ pollinia.Methods:Gynostemium micro-morphology and anatomy of selfing and outcrossing variants of B. bicoloratum was studied by using light and scanning electron microscopy and histological sections. Pollen tube growth in the selfing variant was further observed via X-ray computed microtomography (micro-CT), providing 3D reconstructions of floral tissues at a micron scale.Findings:Selfing variants possess a suberect ('displaced') rostellum rather than the conventional, erect type. Very early in anthesis, the pollinia of selfers are released from the anther and slide down onto the suberect rostellum, where pollen tube growth preferentially occurs through the non-vascularized, i.e. rear (adaxial) and (semi-) lateral parts. This penetrated tissue is comprised of a thin layer of elongate and loosely arranged cells, embedded in stigmatic exudates, as also observed in the stigmatic cavity of both selfing and outcrossing variants.Conclusions:Our results provide the first solid evidence of a stigmatic function for the rostellum in orchid flowers, thereby demonstrating for the first time the feasibility of the micro-CT technique for accurately visualizing pollen tube growth in flowering plants. Rostellum receptivity in B. bicoloratum probably uniquely evolved as an adaptation for reproductive assurance from an outcrossing ancestor possessing an erect (non-receptive) rostellum. These findings open up new avenues in the investigation of an organ that apparently re-gained its 'primordial function' of being penetrated by pollen tubes. © 2013 Gamisch et al.


PubMed | University of Reunion Island, Kadoorie Farm and Botanic Garden Corporation and University of Salzburg
Type: Journal Article | Journal: Heredity | Year: 2016

Bulbophyllum occultum, an epiphytic orchid mainly distributed in the rainforests of (north)eastern Madagascar and La Runion, represents an interesting model case for testing the effects of anthropogenic vs historical (e.g., climate induced) habitat isolation and long-distance colonization on the genetic structure of plant species with disjunct distributions in the Madagascan region. To this aim, we surveyed amplified fragment length polymorphisms (AFLPs) across 13 populations in Madagascar and nine in La Runion (206 individuals in total). We found overall high levels of population subdivision ((PT)=0.387) and low within-population diversity (H(E), range: 0.026-0.124), indicating non-equilibrium conditions in a mainly selfing species. There was no impact of recent deforestation (Madagascar) or habitat disturbance (La Runion) detectable on AFLP diversity. K-means clustering and BARRIER analyses identified multiple gene pools and several genetic breaks, both within and among islands. Inter-island levels of population genetic diversity and subdivision were similar, whereby inter-individual divergence in flower colour explained a significant part of gene pool divergence in La Runion. Our results suggest that (i) B. occultum persisted across multiple isolated (refugial) regions along the eastern rainforest corridor of Madagascar over recent climatic cycles and (ii) populations in La Runion arose from either single or few independent introductions from Madagascar. High selfing rates and sufficient time for genetic drift likely promoted unexpectedly high population genetic and phenotypic (flower colour) differentiation in La Runion. Overall, this study highlights a strong imprint of history on the genetic structure of a low-gene-dispersing epiphytic orchid from the Madagascan region.


Gamisch A.,University of Salzburg | Fischer G.A.,Kadoorie Farm and Botanic Garden Corporation | Comes H.P.,University of Salzburg
BMC Evolutionary Biology | Year: 2015

Background: The transition from outcrossing to selfing has long been portrayed as an 'evolutionary dead end' because, first, reversals are unlikely and, second, selfing lineages suffer from higher rates of extinction owing to a reduced potential for adaptation and the accumulation of deleterious mutations. We tested these two predictions in a clade of Madagascan Bulbophyllum orchids (30 spp.), including eight species where auto-pollinating morphs (i.e., selfers, without a 'rostellum') co-exist with their pollinator-dependent conspecifics (i.e., outcrossers, possessing a rostellum). Specifically, we addressed this issue on the basis of a time-calibrated phylogeny by means of ancestral character reconstructions and within the state-dependent evolution framework of BiSSE (Binary State Speciation and Extinction), which allowed jointly estimating rates of transition, speciation, and extinction between outcrossing and selfing. Results: The eight species capable of selfing occurred in scattered positions across the phylogeny, with two likely originating in the Pliocene (ca. 4.4-3.1 Ma), one in the Early Pleistocene (ca. 2.4 Ma), and five since the mid-Pleistocene (ca. ≤ 1.3 Ma). We infer that this scattered phylogenetic distribution of selfing is best described by models including up to eight independent outcrossing-to-selfing transitions and very low rates of speciation (and either moderate or zero rates of extinction) associated with selfing. Conclusions: The frequent and irreversible outcrossing-to-selfing transitions in Madagascan Bulbophyllum are clearly congruent with the first prediction of the dead end hypothesis. The inability of our study to conclusively reject or support the likewise predicted higher extinction rate in selfing lineages might be explained by a combination of methodological limitations (low statistical power of our BiSSE approach to reliably estimate extinction in small-sized trees) and evolutionary processes (insufficient time elapsed for selfers to go extinct). We suggest that, in these tropical orchids, a simple genetic basis of selfing (via loss of the 'rostellum') is needed to explain the strikingly recurrent transitions to selfing, perhaps reflecting rapid response to parallel and novel selective environments over Late Quaternary (≤ 1.3 Ma) time scales. © 2015 Gamisch et al.


Gamisch A.,University of Salzburg | Fischer G.A.,Kadoorie Farm and Botanic Garden Corporation | Comes H.P.,University of Salzburg
BMC Evolutionary Biology | Year: 2016

Background: Species or clades may retain or shift their environmental niche space over evolutionary time. Understanding these processes offers insights into the environmental processes fuelling lineage diversification and might also provide information on past range dynamics of ecosystems. However, little is known about the relative contributions of niche conservatism versus niche divergence to species diversification in the tropics. Here, we examined broad-scale patterns of niche evolution within a Pliocene-Pleistocene clade of epiphytic Bulbophyllum orchids (30 spp.) whose collective distribution covers the northwest and eastern forest ecosystems of Madagascar. Results: Using species occurrence data, ecological niche models, and multivariate analyses of contributing variables, we identified a three-state niche distribution character for the entire clade, coinciding with three major forest biomes viz. phytogeographical provinces in Madagascar: A, Northwest 'Sambirano'; B, 'Eastern Lowlands'; and C, 'Central Highlands'. A time-calibrated phylogeny and Bayesian models of niche evolution were then used to detect general trends in the direction of niche change over the clade's history (≤5.3 Ma). We found highest transitions rates between lowlands (A and B) and (mostly from B) into the highland (C), with extremely low rates out of the latter. Lowland-to-highland transitions occurred frequently during the Quaternary, suggesting that climate-induced vegetational shifts promoted niche transitions and ecological speciation at this time. Conclusions: Our results reveal that niche transitions occurred frequently and asymmetrically within this Madagascan orchid clade, and in particular over Quaternary time scales. Intrinsic features germane to Bulbophyllum (e.g., high dispersal ability, drought tolerance, multiple photosynthetic pathways) as well as extrinsic factors (ecological, historical) likely interacted to generate the niche transition patterns observed. In sum, our results support the emerging idea of dramatic environmental and climatic fluctuations in Madagascar during the recent geological past, which overturns the long-held paradigm of long-term stability in tropical forest settings. The generality of the patterns and timings reported here awaits the availability of additional comparative studies in other Madagascan endemics. © 2016 Gamisch et al.


PubMed | Kadoorie Farm and Botanic Garden Corporation and University of Salzburg
Type: | Journal: BMC evolutionary biology | Year: 2015

The transition from outcrossing to selfing has long been portrayed as an evolutionary dead end because, first, reversals are unlikely and, second, selfing lineages suffer from higher rates of extinction owing to a reduced potential for adaptation and the accumulation of deleterious mutations. We tested these two predictions in a clade of Madagascan Bulbophyllum orchids (30 spp.), including eight species where auto-pollinating morphs (i.e., selfers, without a rostellum) co-exist with their pollinator-dependent conspecifics (i.e., outcrossers, possessing a rostellum). Specifically, we addressed this issue on the basis of a time-calibrated phylogeny by means of ancestral character reconstructions and within the state-dependent evolution framework of BiSSE (Binary State Speciation and Extinction), which allowed jointly estimating rates of transition, speciation, and extinction between outcrossing and selfing.The eight species capable of selfing occurred in scattered positions across the phylogeny, with two likely originating in the Pliocene (ca. 4.4-3.1 Ma), one in the Early Pleistocene (ca. 2.4 Ma), and five since the mid-Pleistocene (ca. 1.3 Ma). We infer that this scattered phylogenetic distribution of selfing is best described by models including up to eight independent outcrossing-to-selfing transitions and very low rates of speciation (and either moderate or zero rates of extinction) associated with selfing.The frequent and irreversible outcrossing-to-selfing transitions in Madagascan Bulbophyllum are clearly congruent with the first prediction of the dead end hypothesis. The inability of our study to conclusively reject or support the likewise predicted higher extinction rate in selfing lineages might be explained by a combination of methodological limitations (low statistical power of our BiSSE approach to reliably estimate extinction in small-sized trees) and evolutionary processes (insufficient time elapsed for selfers to go extinct). We suggest that, in these tropical orchids, a simple genetic basis of selfing (via loss of the rostellum) is needed to explain the strikingly recurrent transitions to selfing, perhaps reflecting rapid response to parallel and novel selective environments over Late Quaternary ( 1.3 Ma) time scales.


Abbas S.,Hong Kong Polytechnic University | Nichol J.E.,Hong Kong Polytechnic University | Fischer G.A.,Kadoorie Farm and Botanic Garden Corporation
Science of the Total Environment | Year: 2016

Forested areas of the world decreased by 129 million hectare during the past quarter-century, and only 35 % of remainder is primary forest. Secondary forests are therefore relatively more important for biodiversity conservation, catchment protection, climate control, and the ecological services they provide. Many governments expend large resources on afforestation projects, which may not be supported by objective data on rates and pathways of natural succession in secondary forest. This paper describes a 70-year succession of tropical forest in Hong Kong under different management regimes including afforestation programs, frequent fire, and fire protection. From complete destruction of its forest during the Second World War, forest has established rapidly in areas where a shrub cover was able to colonize. The practice of afforestation as a nursery stage on degraded hillsides, for establishment of forest seedlings by natural invasion is not supported by the evidence, as when the native Pinus massoniana plantations were eliminated by disease during the 1970s, no forest or woody species were seen in the areas affected. In fact there was a reversion to grassland, which persisted there for almost three decades, until recent shrub invasion. The fastest period of forest regeneration, at 10.9% annually between 1989 and 2001, occurred when shrubland edge was greatest and forest was able to colonize across interfluves between linear-shaped riparian shrublands in valley bottoms. After 2001, succession to forest was slower, at 7.8% annually, as forest patches consolidated and edge habitats reduced. Effective forest management policies could include seeding of native shrubs extending linearly from established forest, to maximize edge length between woody species and grasslands, and planting of late successional species in areas where forest pioneers are in decline. © 2015 Elsevier B.V.

Loading Kadoorie Farm and Botanic Garden Corporation collaborators
Loading Kadoorie Farm and Botanic Garden Corporation collaborators