Partitioning the functional variation of tree seedlings during secondary succession in a tropical lowland rainforest

Abstract

The seedling stage is a key phase in the regeneration dynamics of forest communities. The functional diversity of tree seedlings is closely related to the structuring and functioning of forest ecosystems. Here, we examined and partitioned variations of tree seedlings in functional diversity over a chronosequence (younger secondary forest, 18–30 yr; older secondary forest, 60 yr; and old growth forest) after shifting cultivation in a tropical lowland rainforest area on Hainan Island, China. Results showed that the variations of seedling functional diversities revealed a unimodal pattern during the secondary succession. The functional diversities of seedlings were overall lower in the secondary than in old growth forests. The relative role of edaphic factors and tree community factors changed with the successional process. The variations in functional diversity explained by edaphic factors were higher than those by tree community factors in the younger secondary forest. However, with the procession of secondary succession, variations in functional diversities of seedlings explained by tree community factors were increasing. The determinants for functional diversities of seedlings varied with successional stages. Seedling functional diversities were affected by edaphic factors in the younger secondary growth forest. Meanwhile, in the older secondary forest, seedling functional diversities were affected mostly by soil nutrients and tree community factors. In the old growth forest, seedling functional diversities were affected by available nitrogen and tree community factors. Our results suggest that edaphic factors play an important role in the younger secondary forest, while tree community factors in the older secondary forest and unexplained factors in the old growth forest.

Plant Diversity and Soil Nutrients in a Tropical Coastal Secondary Forest: Association Ordination and Sampling Year Differences

“…The decline in the dominant species in the two different years changed; the species with greater decline ratios may be removed in the future for forest restoration. Moreover, it is reported that the species with lower decline ratios possibly conserve for longer periods of time [57]. Nonetheless, these species possibly create enough space for dominant species during their maturity.…”

Intra- and inter-specific responses of plant functional traits to environmental variables: implications for community ecology in the tropical monsoonal dwarf forest on Hainan Island

“…The decline in the dominant species altered and species with higher decline ratios were possibly removed for forest conservation in the following years. Furthermore, species with lower decline ratios have been suggested to conserve for longer periods (Lu et al, 2018). However, at the secondary stage of succession, these species may be creating enough space for the most prevalent species.…”

Sorption mechanisms of lead on soil-derived black carbon formed under varying cultivation systems

“…Unraveling the sorption characteristics and mechanisms of PTEs on SBC from agricultural and forestry soils can help exploring the potential of BC or biochar in influencing the immobilization of PTEs in agricultural and forestry lands. The natural tropical rainforest in the Bawangling Forest Region (108.88°-109.33°E, 18.86°-19.20°N) of Hainan island in China (Lu et al, 2018) was rarely disturbed for replacing its plantations, and has therefore existed for several thousand years without any cultivation (Zhang et al, 2010;Wang et al, 2017a), except a serious damage caused by people for creating more farmland or for obtaining more forest resources about 600 years ago in the Ming Dynasty (Dodson et al, 2019). The lands nearby the Bawangling Forest Region have been cultivated for about years (Lu et al, 2018).…”

“…The natural tropical rainforest in the Bawangling Forest Region (108.88°-109.33°E, 18.86°-19.20°N) of Hainan island in China (Lu et al, 2018) was rarely disturbed for replacing its plantations, and has therefore existed for several thousand years without any cultivation (Zhang et al, 2010;Wang et al, 2017a), except a serious damage caused by people for creating more farmland or for obtaining more forest resources about 600 years ago in the Ming Dynasty (Dodson et al, 2019). The lands nearby the Bawangling Forest Region have been cultivated for about years (Lu et al, 2018). Rubber trees near the Bawangling Forest Region was adopted as the secondary plantation under less intensive cultivation (cultivated about 20 years ago) system, while vegetables were grown twice a year in some lands under highly intensive cultivation system.…”