Floral traits of woody plants and their habitat differentiations in a northern tropical karst forest

Abstract

The diversification of floral traits is the outcome of evolution by natural selection, and the variation in floral traits between species has a certain correlation with the plant habitats. The northern tropical karst seasonal rain forests have a great habitat heterogeneity, a complex structure of plant community, and abundant endemic components. Analyzing the relationship between the variation of plant traits and their habitats in those forests is helpful to understand species coexistence, coevolution and their adaptations to habitats, and to provide clues for revealing the ecological adaptability of plants and the maintenance mechanisms of biodiversity in karst forests. We conducted a preliminary study at a 15 ha plot of the northern tropical karst seasonal rain forest in Nonggang to examine the differences in floral traits among species and how these traits varied with habitats, when a relatively large number of woody plants bloomed synchronously, with a total of 21 species being found flowering. We divided the 21 species into three preferred habitat types (peak, slope and valley) according to the spatial distribution of species and their habitat associations, and analysed

Leaf Traits and Water-Use Characteristics of Impatiens hainanensis, a Limestone-Endemic Plant under Different Altitudes in Dry and Foggy Seasons

“…As the altitude rises, the degree in drought gradually increases, bare leakage increases, soil water content decreases, and plant habitat become more hostile. The smaller the specific leaf area of I. hainanensis, the greater the water-use efficiency and osmoregulation capacity, and the greater the dry matter content of the leaves, presenting a higher resource-use efficiency and thus more biomass to resist the drought habitat [51,52]. The higher leaf area, leaf thickness, and specific leaf area and the relatively low leaf dry matter content of I. hainanensis from low and mid altitude populations may result from competition for more light and water in the tropical rainforest, where I. hainanensis increases leaf area carbon investment by increasing leaf area and by reducing leaf thickness carbon build-up.…”

Seasonal Differences in Water-Use Sources of Impatiens hainanensis (Balsaminaceae), a Limestone-Endemic Plant Based on “Fissure-Soil” Habitat Function

“…This difference in water use reflects the functional characteristics of the soil type and the community structure of I. hainanensis in shallow karst rift habitats, as well as the adaptation of I. hainanensis to different water conditions between the dry and wet seasons. The temporal and spatial dynamics of soil water δD are influenced by differences in precipitation δD and precipitation magnitudes, which are dependent on the intensity of precipitation and evaporation of soil water δD values and infiltration [42][43][44][45]. In the wet season, soil water δD values were in between precipitation values and epikarst water values.…”