Investigation and research are extremely challenging in tropical rainforests, which possess powerful ecological functions. One reason is the diversity of tree species, particularly the canopy trees, which have unstable flowering periods, blooming twice in one year or not at all for several years, making surveys exceedingly difficult.

Another reason is the complex vertical structure of the communities, where the trees layer can be divided into four or five strata, with overlapping canopies and high tree trunks, along with liana crowns and epiphytes (especially in karst forests), making observations highly prone to misinterpretation, necessitating reliance on labor-intensive and delicate observation of bark characteristics as well as drone technology for accurate identification.

To date, there has been no report on an "infographic" with complete on-site morphological characteristics for the typical large dynamic plots (25-50 ha) in tropical rainforests (https://forestgeo.si.edu/ and http://www.cncdiversitas.cn/zyxm/cforbio/js/  ).

After three years of arduous work (2022-2024), the Research Group of Speciation and Evolution of Karst Plants (SEKP) at the Kunming Institute of Botany, Chinese Academy of Sciences (KIB/CAS) constructed an "infographic" of a typical tropical rainforest dynamic plot (Fig. 1).

The 25-ha karst tropical rainforest dynamic plot in Gulingqing, southeastern Yunnan, was established in strict accordance with the CTFS-ForestGEO standards (https://forestgeo.si.edu/) and has been incorporated into the Chinese Forest Biodiversity Monitoring Network (CForBio), following the standards of the dynamic plot (selecting relatively flat areas to establish plot according to topographic features).

KIB, and the Management Bureau of Maguan Gulingqing Provincial Nature Reserve are the co-constructing institutions. For standardized management, entry into the plot requires reporting and wearing safety helmets, among other requirements (Fig. 2).

The plot is a karst depression with an altitude range of 530-613 meters, a vertical height difference of 83 meters, relatively gentle terrain, and rock outcrops accounting for 44.7%. It is shrouded in fog throughout the year. Established in 2021, relying on the renovation project of the "Southeastern Yunnan Tropical Mountain Forest Ecosystem Research Station" of the CAS, tree individual measurement work was completed in 2022.

From 2023 to 2024, the names of some trees were revised with several observations, and the observed data were improved and standardized. Finally, the composition of 381 tree species (DBH ≥ 1cm) in the plot was determined, including 81 large tree species (DBH ≥ 60cm).

Fig. 1 Infographic of the 25-ha karst tropical rainforest dynamic plot in Gulingqing, Yunnan, China 

(Image by KIB)

Fig. 2 Assoc Prof Wenhong Chen checked the quality of census data at the Gulinqing Dynamic plot in 2022 

(Image by KIB)

A monograph titled "Gulinqing Karst Tropical Rain Forest Dynamic Plot: Biodiversity and Tree Distribution Patterns" has recently been published by Yunnan Science and Technology Press (Fig. 3).

The highlights of this book are as follows:

Frist, it provides a preliminary definition of various types of rocks (Fig. 4), helping for the subsequent delineation of species' ecological niches;

Second, it details several unique and common ecological phenomena in the tropical rainforest within the plot, such as buttress roots, drip tips, cauliflory, and nodding foliage leaves;

Third, it figured out the diversity of various plant organs in the plot, including the morphological diversity of roots (octopus roots, which are defined and introduced for the first time in this book; aerial roots or pneumatophores, etc.), stems (mainly introducing the morphological characteristics of barks and classifying them), leaves (compound leaves, simple leaves, leaf area size, swollen petioles, etc.), flowers and inflorescences (types of flowers, covering almost all inflorescence types), fruits (aggregate fruits, multiple fruits, drupes, berries, capsules, etc.), and seeds;

Fourthly, most species are accompanied by pictures of trunk surfaces, and a preliminary classification of barks is conducted;

Fifth, it analyzes the species composition in the plot, and the dominant species based on important values are Pometia pinnata, Diospyros sumatrana, Mitrephora calcarea, Brassaiopsis grushvitzkyi, Parashorea chinensis, and Garcinia fagraeoides, which exactly belong to two series of rock and soil ecological niches;

Sixth, it briefly introduces some common or conspicuous species of animals (including Insecta, Amphibia, Reptilia, and Aves) and macrofungi in and around the plot;

Seventh, there are 77 species with compound leaves in the plot, most of which are pinnately compound leaves, which requires further research.

Fig. 3 “Gulinqing Karst Tropical Rain Forest Dynamic Plot: Biodiversity and Tree Distribution Patterns”

 (Image by KIB)

Fig. 4 Shapes of various surface rocks in Gulinqing plot (partial) (Image by KIB) 

In addition, the key part of the book is that, in addition to information such as diameter classes and distribution patterns, all 381 tree species are accompanied by exquisite morphological characteristic diagrams, especially close-up photos of trunks (or stems); it also includes a new large arbor species, Diospyros crystallina (tree height 30-35 meters, dioecious, flowering once every 3 years) (Fig. 1).

The literature is cited as follows: Chen WH, Shui YM, Shi TF, Lyu L, Huang Q. 2025. Gulinqing Karst Tropical Rain Forest Dynamic Plot: Biodiversity and Tree Distribution Patterns. Kunming: Yunnan Science & Technology Press.

Contact:

YANG Mei
General Office
Kunming Institute of Botany, CAS

email: yangmei@mail.kib.ac.cn

(Editor: YANG Mei)