Papers by Richard T Corlett
BMC Evolutionary Biology, 2019
Background The genus Ilex (Aquifoliaceae) has a near-cosmopolitan distribution in mesic habitats ... more Background The genus Ilex (Aquifoliaceae) has a near-cosmopolitan distribution in mesic habitats from tropical to temperate lowlands and in alpine forests. It has a high rate of hybridization and plastid capture, and comprises four geographically structured plastid groups. A previous study showed that the plastid rbcL gene, coding for the large subunit of Rubisco, has a particularly high rate of non-synonymous substitutions in Ilex, when compared with other plant lineages. This suggests a strong positive selection on rbcL, involved in yet unknown adaptations. We therefore investigated positive selection on rbcL in 240 Ilex sequences from across the global range. Results The rbcL gene shows a much higher rate of positive selection in Ilex than in any other plant lineage studied so far (> 3000 species) by tests in both PAML and SLR. Most positively selected residues are on the surface of the folded large subunit, suggesting interaction with other subunits and associated chaperones,...
Scientific reports, Jan 12, 2018
The interaction between pollinating wasps and figs is an obligate plant-insect mutualism, and the... more The interaction between pollinating wasps and figs is an obligate plant-insect mutualism, and the ca. 750 Ficus species are mainly tropical. Climatic constraints may limit species distributions through their phenology and this seems particularly likely for figs, where phenological mismatches can cause local extinction of the short-lived pollinators. We therefore compared the phenologies of Ficus altissima, F. racemosa and F. semicordata in tropical Xishuangbanna (21°55'N) and subtropical Liuku (25°50'N), SW China, to understand what factors limit fig distributions near their northern limits. All species produced synchronous crops of syconia in Xishuangbanna but production in Liuku was continuous, which may help maintain pollinator populations. However, in general, we found decreased fitness at the northern site: slower syconium development, so fewer crops each year; fewer seeds per syconium (two species); and fewer pollinators and more non-pollinators per syconium, so less p...
Tropical Conservation Science, 2015
Asian tropical forests are under extreme stress from clearance, fragmentation, and logging. Becau... more Asian tropical forests are under extreme stress from clearance, fragmentation, and logging. Because Singapore suffered these same impacts in the 19th century, it can act as an early warning system for the region. We identified invasive exotic tree species from a comprehensive survey, assessed their survival and growth in the open and under a forest canopy, and compared their traits with native pioneers and widely planted exotic species that have failed to naturalize. Nine species were invasive: Acacia auriculiformis (ear-leaf acacia), Cecropia pachystachya (trumpet tree), Falcataria moluccana (Moluccan albizia), Leucaena leucocephala (leucaena), Manihot carthaginensis subp. glaziovii (Ceara rubber tree), Muntingia calabura (Jamaican cherry tree), Piper aduncum (spiked pepper), Pipturus argenteus (white mulberry), and Spathodea campanulata (African tulip tree). Under the forest canopy, all grew little and suffered high (75–100%) mortality, with Spathodea surviving best. At the open s...
Scientific reports, Jan 12, 2015
The many species of figs (Ficus, Moraceae) have evolved a variety of reproductive phenologies tha... more The many species of figs (Ficus, Moraceae) have evolved a variety of reproductive phenologies that ensure the survival of both the fig plants and their short-lived, species-specific, pollinating wasps. A phenological study of 28 male and 23 female plants of a dioecious hemiepiphytic fig, Ficus tinctoria, was conducted in Xishuangbanna, SW China at the northern margin of tropical SE Asia. In contrast to other figs of seasonal climates, which have a winter low in fig production, both sexes produced their major fig crops at the coldest time of the year. Male plants released pollinators during the period when most female trees were receptive and male syconia had a long wasp-producing (D) phase, which ensured high levels of pollination. Female crops ripened at the end of the dry season, when they attracted numerous frugivorous birds and dispersed seeds can germinate with the first reliable rains. Few syconia were produced by either sex during the rest of the year, but these were sufficie...
Regional Environmental Change, 2019
Scientific Reports, 2022
Although 23% of Thailand’s land is in protected areas, these are vulnerable to climate change. We... more Although 23% of Thailand’s land is in protected areas, these are vulnerable to climate change. We used spatial distribution modelling for 866 vertebrate and 591 plant species to understand potential climate change impacts on species in protected areas. Most mammals, birds, and plants were projected to decline by 2070, but most amphibians and reptiles were projected to increase. By 2070 under RCP8.5, 54% of modeled species will be threatened and 11 nationally extinct. However, SDMs are sensitive to truncation of the climate space currently occupied by habitat loss and hunting, and apparent truncation by data limitations. In Thailand, lowland forest clearance has biased records for forest-dependent species to cooler uplands (> 250 m a.s.l.) and hunting has confined larger vertebrates to well-protected areas. In contrast, available data is biased towards lowland non-forest taxa for amphibians and reptiles. Niche truncation may therefore have resulted in overestimation of vulnerabili...
Forests, 2020
Research Highlights: The reasons for persistence of forest fragments in human-dominated landscape... more Research Highlights: The reasons for persistence of forest fragments in human-dominated landscapes have rarely been examined, despite their importance in biodiversity and ecosystem services. We determined these reasons for forest fragments on collective land in Xishuangbanna prefecture, southwest China. Background and Objectives: Reconciling economic development with biodiversity conservation has been a major challenge in China’s small tropical land area, where local realities have often been in conflict with national policies. In Xishuangbanna, much of China’s most biodiverse forest area has been replaced by cash crops in recent decades, but numerous small forest fragments remain on collective land. Our objective was to find out why these fragments have not been cleared. Methods: We used a combination of semi-structured interviews with 600 households in 69 villages representing nine ethnic groups and information from key informants. Results: Overall, 64% of individual households re...
Global Ecology and Conservation, 2021
China is home to a small but expanding population of wild Asian elephants (Elephas maximus). Both... more China is home to a small but expanding population of wild Asian elephants (Elephas maximus). Both research interest and conservation efforts have increased in recent years, but these have been fragmented. Here we present the results from a collaborative, multi- sectorial, multi-stakeholder exercise to identify priorities for Chinese elephant research and conservation. We first compiled a comprehensive list of issues, categorized under nine research and nine conservation themes, through an on-line survey of stakeholders. These issues were subsequently consolidated, timelined (as short-, mid-, or long-term issues), and ranked by their perceived priority in a two-day workshop attended by 44 people representing 28 organizations. The initial list of 656 issues (337 research and 319 conservation) was consolidated into a list of 251 (121 research and 130 conservation) issues. After priority ranking, we retained the top-three issues within each theme (making a total of 55 priority issues, due to a tie), which are then discussed in detail in this paper. Most (87%, n = 55) priority issues were classified as short-term, suggesting that the exercise might have succeeded in identifying the current priorities, but not emerging issues that might require attention in future. Some issues appeared in various forms in different themes. Among research questions, participants highlighted the importance of understanding the carrying capacity of the current elephant range habitats, elephant movement patterns and expected range changes, the drivers of human-elephant conflict (HEC), improvements to the current HEC financial compensation mechanism, and ways of engaging local communities in HEC mitigation. Regarding elephant conservation, recurrent issues included effectively engaging communities, improving HEC early-warning systems and financial compensation mechanisms, establishing a new national park within elephant range, and creating mechanisms for communication and collaboration among elephant research and conservation stakeholders in China. Our exercise was effective in engaging experts from a diversity of different sectors and organizations in discussions about Asian elephants in China, and generated a list of priorities that can help guide elephant research and conservation efforts.
Sustainability, 2021
Protected areas are the backbone of biodiversity conservation but vulnerable to climate change. T... more Protected areas are the backbone of biodiversity conservation but vulnerable to climate change. Thailand has a large and well-planned protected area system, covering most remaining natural vegetation. A statistically derived global environmental stratification (GEnS) was used to predict changes in bioclimatic conditions across the protected area system for 2050 and 2070, based on projections from three CMIP5 earth system models and two representative concentration pathways (RCPs). Five bioclimatic zones were identified composed of 28 strata. Substantial spatial reorganization of bioclimates is projected in the next 50 years, even under RCP2.6, while under RCP8.5 the average upward shift for all zones by 2070 is 328–483 m and the coolest zone disappears with two models. Overall, 7.9–31.0% of Thailand’s land area will change zone by 2070, and 31.7–90.2% will change stratum. The consequences for biodiversity are less clear, particularly in the lowlands
where the existing vegetation mosaic is determined largely by factors other than climate. Increasing connectivity of protected areas along temperature and rainfall gradients would allow species to migrate in response to climate change, but this will be difficult in much of Thailand. For isolated protected areas and species that cannot move fast enough, more active, species-specific interventions may be necessary. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Climate, 2020
Protected areas are the backbone of biodiversity conservation but are fixed in space and vulnerab... more Protected areas are the backbone of biodiversity conservation but are fixed in space and vulnerable to anthropogenic climate change. Myanmar is exceptionally rich in biodiversity but has a small protected area system. This study aimed to assess the potential vulnerability of this system to climate change. In the absence of good biodiversity data, we used a spatial modeling approach based on a statistically derived bioclimatic stratification (the Global Environmental Stratification, GEnS) to understand the spatial implications of projected climate change for Myanmar's protected area system by 2050 and 2070. Nine bioclimatic zones and 41 strata were recognized in Myanmar, but their representation in the protected area system varied greatly, with the driest zones especially underrepresented. Under climate change, most zones will shift upslope, with some protected areas projected to change entirely to a new bioclimate. Potential impacts on biodiversity include mountaintop extinctions of species endemic to isolated peaks, loss of climate specialists from small protected areas and those with little elevational range, and woody encroachment into savannas and open forests as a result of both climate change and rising atmospheric CO 2. Myanmar needs larger, better connected, and more representative protected areas, but political, social, and economic problems make this difficult.
Plant Diversity, 2020
Myanmar is botanically rich and floristically diverse: one of the world's biodiversity hotspots. ... more Myanmar is botanically rich and floristically diverse: one of the world's biodiversity hotspots. However, Myanmar is still very unevenly explored, and until a plant checklist was published in 2003, relatively little work was done on its flora. This checklist included 11,800 species of spermatophytes in 273 families. Since this checklist was published, the botanical exploration of Myanmar has accelerated and there have been many additional publications. We therefore surveyed the literature of taxonomic contributions to Myanmar's vascular flora over the last 20 years (2000e2019) and compiled a list of new and newly described taxa. Our list includes 13 genera, 193 species, 7 subspecies, 19 varieties, and 2 forms new to science; and 3 families, 34 genera, 347 species, 4 subspecies, 7 varieties, and 1 form newly recorded in Myanmar. Altogether, they represent 91 families and 320 genera. Most of the new discoveries belong to 15 families, with more than 25% (146 taxa) belonging to Orchidaceae. These new discoveries are unevenly distributed in the country, with about 41% of the newly discovered species described from Kachin State in northeast Myanmar. This reflects the incompleteness of our current knowledge of the flora of Myanmar and the urgent need for a greatly expanded effort. The completion of the flora of Myanmar requires more fieldwork from north to south, taxonomic studies on new and existing collections, and some mechanism that both coordinates the efforts of various international institutions and initiatives and encourages continued international cooperation. In addition, producing modern taxonomic treatments of the flora of Myanmar requires the participation of experts on all vascular plant families and genera. There is also an urgent need to attract young scientists to plant taxonomy, to work on inventories, identification, nomenclature, herbarium work, and comparative studies.
Plant Diversity, 2020
The Anthropocene is marked by twin crises: climate change and biodiversity loss. Climate change h... more The Anthropocene is marked by twin crises: climate change and biodiversity loss. Climate change has tended to dominate the headlines, reflecting, in part, the greater complexity of the biodiversity crisis. Biodiversity itself is a difficult concept. Land plants dominate the global biomass and terrestrial ar-thropods probably dominate in terms of numbers of species, but most of the Tree of Life consists of single-celled eukaryotes, bacteria, and archaea. Wild plants provide a huge variety of products and services to people, ranging from those that are species-specific, such as food, medicine, and genetic resources, to many which are partly interchangeable, such as timber and forage for domestic animals, and others which depend on the whole community, but not on individual species, such as regulation of water supply and carbon sequestration. The use of information from remote sensing has encouraged a simplified view of the values of nature's contributions to people, but this does not match the way most people value nature. We can currently estimate the proportion of species threatened by human impacts only for a few well-assessed groups, for which it ranges from 14% (birds) to 63% (cycads). Less than 8% of land plants have been assessed, but it has been estimated that 30e44% are threatened, although there are still few (0.2%) well-documented extinctions. Priorities for improving protection of biodiversity include: improving the inventory, with surveys focused on geographical areas and taxonomic groups which are under-collected; expanding the protected area system and its representativeness; controlling overexploitation; managing invasive species; conserving threatened species ex situ; restoring degraded ecosystems; and controlling climate change. The Convention on Biological Diversity (CBD) COP15 and the United Nations Framework Convention on Climate Change (UNFCCC) COP26 meetings, both postponed to 2021, will provide an opportunity to address both crises, but success will require high ambition from all participants.
Forests, 2020
Research Highlights: The reasons for persistence of forest fragments in human-dominated landscape... more Research Highlights: The reasons for persistence of forest fragments in human-dominated landscapes have rarely been examined, despite their importance in biodiversity and ecosystem services. We determined these reasons for forest fragments on collective land in Xishuangbanna prefecture, southwest China. Background and Objectives: Reconciling economic development with biodiversity conservation has been a major challenge in China's small tropical land area, where local realities have often been in conflict with national policies. In Xishuangbanna, much of China's most biodiverse forest area has been replaced by cash crops in recent decades, but numerous small forest fragments remain on collective land. Our objective was to find out why these fragments have not been cleared. Methods: We used a combination of semi-structured interviews with 600 households in 69 villages representing nine ethnic groups and information from key informants. Results: Overall, 64% of individual households retained forest fragments on the land allocated to them, and 93% of villages retained larger areas managed as a collective forest. Most (71%) interviewees said that fragments on their own land were on sites of low agricultural value and were retained as fuelwood sources. They were also often (33%) underplanted with crops and supplied other forest products. All interviewees attributed the retention of collective forests to policy restrictions on clearance, with most (96%) mentioning cultural and religious uses and many recognizing environmental benefits. Most were also used as sources of wild edible plants (61%) and other forest products. Many said these collective forests had shrunk over time, particularly in areas suitable for profitable cultivation. Conclusions: China's new ecological redline policy will protect most larger patches of forest in Xishuangbanna, but the smaller fragments on land allocated to individual households are also of conservation value, particularly in areas with no other forest. Some form of compensation scheme is needed to encourage their continued retention.
Zoological Research, 2020
The outbreak of COVID-19 started in mid-December 2019 in Wuhan, China. Up to 29 February ... more The outbreak of COVID-19 started in mid-December 2019 in Wuhan, China. Up to 29 February 2020, SARS-CoV-2 (HCoV-19 / 2019-nCoV) had infected more than 85 000 people in the world. In this study, we used 93 complete genomes of SARS-CoV-2 from the GISAID EpiFluTM database to investigate the evolution and human-to-human transmissions of SARS-CoV-2 in the first two months of the outbreak. We constructed haplotypes of the SARS-CoV-2 genomes, performed phylogenomic analyses and estimated the potential population size changes of the virus. The date of population expansion was calculated based on the expansion parameter tau (τ) using the formula t=τ/2u. A total of 120 substitution sites with 119 codons, including 79 non-synonymous and 40 synonymous substitutions, were found in eight coding-regions in the SARS-CoV-2 genomes. Forty non-synonymous substitutions are potentially associated with virus adaptation. No combinations were detected. The 58 haplotypes (31 found in samples from China and 31 from outside China) were identified in 93 viral genomes under study and could be classified into five groups. By applying the reported bat coronavirus genome (bat-RaTG13-CoV) as the outgroup, we found that haplotypes H13 and H38 might be considered as ancestral haplotypes, and later H1 was derived from the intermediate haplotype H3. The population size of the SARS-CoV2 was estimated to have undergone a recent expansion on 06 January 2020, and an early expansion on 08 December 2019. Furthermore, phyloepidemiologic approaches have recovered specific directions of human-to-human transmissions and the potential sources for international infected cases.
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Papers by Richard T Corlett
where the existing vegetation mosaic is determined largely by factors other than climate. Increasing connectivity of protected areas along temperature and rainfall gradients would allow species to migrate in response to climate change, but this will be difficult in much of Thailand. For isolated protected areas and species that cannot move fast enough, more active, species-specific interventions may be necessary. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
where the existing vegetation mosaic is determined largely by factors other than climate. Increasing connectivity of protected areas along temperature and rainfall gradients would allow species to migrate in response to climate change, but this will be difficult in much of Thailand. For isolated protected areas and species that cannot move fast enough, more active, species-specific interventions may be necessary. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY