Stephan W. Gale’s research while affiliated with Kadoorie Farm and Botanic Garden and other places

Both abiotic conditions and management influence the success of forest restoration. Despite growing interest and practical effort in restoring degraded forest landscapes, understanding of how disparate factors, such as terrain, soil conditions, climate and silvicultural treatments, directly or collectively control species performance and shape community recovery remains limited. In this study, we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration. To do so, we established seven experimental plots, each measuring 20 m × 20 m (400 m ² ) subdivided into 48 subplots, in coarse, anthropogenic grassland on a mid-elevation mountain slope in Hong Kong, and planted a total of 3975 native tree seedlings belonging to 12 tree species within them. To characterise topography, we modelled the elevation, slope, convexity and aspect of each subplot. Two types of tree guard (enclosed blue plastic sleeve and open yellow mesh), two types of fertiliser (organic and inorganic) and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings. Survivorship, height and basal diameter were measured at 1, 2 and 4 years after planting. We used generalised linear models to examine the effect of these factors and their interactions on seedling survival, and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate (RGR) of each species. The most parsimonious models were selected using the Akaike Information Criterion. Survivorship was 98.1%, 95.2% and 86.4% across all plots in the first, second and fourth year, respectively. On average, topographic and management variables explained 1.48–3.34% of total variation in RGR, respectively, for all species. The models revealed that type of tree guard, aspect and elevation were the most important factors explaining RGR and survival. Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment, emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests. Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species. All potential limiting factors pertaining to both site factors and management, as well as their interactions, should be considered in restoration planning to maximise restoration success.

Introduction The terrestrial orchid genus Nervilia is diagnosed by its hysteranthous pattern of emergence but is nested among leafless myco-heterotrophic lineages in the lower Epidendroideae. Comprising ca. 80 species distributed across Africa, Asia and Oceania, the genus remains poorly known and plagued by vague and overlapping species circumscriptions, especially within each of a series of taxonomically intractable species complexes. Prior small-scale, exploratory molecular phylogenetic analyses have revealed the existence of cryptic species, but little is otherwise understood of origin, the scale and timing of its biogeographic spread, or the palaeoclimatic factors that have shaped its ecology and given rise to contemporary patterns of occurrence. Methods Here, we sample widely throughout the generic range, including 45 named taxa and multiple accessions referable to several widespread ‘macrospecies’, as well as material of equivocal identity and probable undescribed status, for the first time enabling an evaluation of taxonomic boundaries at both species and sectional level. Using nuclear (ITS) and plastid (matK, trnL-F) sequence data, we conduct phylogenetic (maximum parsimony and Bayesian inference) and ancestral area analysis to infer relationships and resolve probable origin and colonisation routes. Results The genus is strongly supported as monophyletic, as are each of its three sections. However, the number of flowers in the inflorescence and other floral characters are poor indicators of sectional affinity. Dated ancestral area analysis supports an origin in Africa in the Early Oligocene, with spread eastwards to Asia occurring in the Late Miocene, plausibly via the Gomphotherium land bridge at a time when it supported woodland and savanna ecosystems. Discussion Taxonomic radiation in Asia within the last 8 million years ties in with dramatic Himalayan-Tibetan Plateau uplift and associated intensification of the Asia monsoon. Multiple long-range migrations appear to have occurred thereafter, as the genus colonised Malesia and Oceania from the Pliocene onwards. The bulk of contemporary species diversity is relatively recent, potentially explaining the ubiquity of cryptic speciation, which leaves numerous species overlooked and unnamed. Widespread disjunct species pairs hint at high mobility across continents, extinction and a history of climate-induced vicariance. Persistent taxonomic challenges are highlighted.

Viola tenuis Benth. was first described by George Bentham in 1842, without any type specimen designated, but with a collection record by Richard Brinsley Hinds in 1841. Currently, Viola tenuis is considered a synonym of another species according to Plants of the World Online (POWO). However, based on a combination of morphological and molecular evidence, we propose reinstating Viola tenuis as a distinct species. Our analysis places it within Viola sect. Plagiostigma subsect. Diffusae, where it shows morphological similarities to five other species endemic to Guangdong Province, China. We designated the type of V. tenuis here and assigned additional KFBG specimens to the species.

Many shark species have been overexploited for international markets, including fins for shark fin soup in Southeast Asia. Previous studies highlighted the value of large, threatened shark species, regulated under CITES Appendix II. However, sampling biases may have overlooked small shark species. Here, we address this by identifying species from ~4000 small shark fins in Hong Kong. These fins included species not recorded in previous surveys, raising the market’s species diversity to 106. Nearly 75% of the small fins came from small shark species and 58.1% of small species were threatened with extinction. We identified an important CITES listing gap: Trade in 19 small, threatened species, especially from the family Triakidae, is unregulated. In addition, a quarter of small fins come from large sharks, indicating that substantial exploitation of juveniles is occurring and may be affecting fisheries sustainability. Enhanced surveillance of small shark fin trade is essential to ensure effective conservation under emerging trade regulations.

Begonia hongkongensis F.W.Xing is described and illustrated. Begonia section Platycentrum series Aequilateralibus , to which it belongs, is likely to be an artificial group defined by its symmetrical leaf base, a feature that is atypical for the genus as a whole, but which may have evolved as an adaptation to flash floods since it is associated with rheophytic and streamside species of tropical areas with very high annual rainfall. Variation within the species and relationships with morphologically similar species are discussed.

The Tai Po Kau Forest Dynamics Plot was established in 2015 following standard ForestGEO protocols. It is located within the core area of Tai Po Kau Nature Reserve in the New Territories of Hong Kong S.A.R., China. The plot measures 500 m by 400 m (i.e. 20 hectares, ha) and, in the first census completed in 2015, it contained 81,019 individuals of 172 woody species, amounting to 117,203 stems, each equal to or greater than 1 cm diameter at breast height. These species belong to 111 genera in 53 families. This handbook presents a map indicating the occurrence of each of these species within the plot, as well as notes on their ecology, phenology and key identification characteristics, including photos. The Tai Po Kau Forest Dynamics Plot is the first in the ForestGEO worldwide network to be established in secondary forest. As such, it offers a unique opportunity for integrated research into the impacts of disturbance on tropical biodiversity. This book is therefore intended as a foundation for deepening understanding of the ecology, conservation and restoration of degraded tropical landscapes.