Abstract
Understanding the effects of above- and below-ground interactions on seedling growth is pivotal for identifying the key drivers of secondary forest succession. However, it is still unclear whether the effects of above- and below-ground interactions of plants are consistent for seedling growth of deciduous and evergreen species. There are two types of broadleaved forests (i.e., tropical lowland rainforest and tropical deciduous monsoon rainforest) in the low-elevation (<800 m) areas of Hainan Island in China. Here, 32 seedling transplanting plots (1 × 1 m2) were established in the tropical lowland rainforest and the tropical deciduous monsoon rainforest, respectively. Four treatments (each with 16 replicates) were carried out to reduce above- and below-ground interactions of plants in the low-elevation forests: removal of vegetation (R), root trenching (T), removal of vegetation and root trenching (R + T), and no vegetation removal or trenching (as the control) (C). Seedlings of four deciduous species and four evergreen species were planted to observe their performance in the experiments. The relative growth rates (RGR) of the seedlings were measured to distinguish the relative effects of above- and below-ground interactions. The photosynthetically active radiation (PAR) was measured as a proxy for above-ground interaction and the root biomass was used as a proxy for below-ground interaction. The relationships between seedling RGR and PAR/root biomass were examined. Results showed that: (1) R and R+T treatments significantly increased the seedlings RGR, but T treatment had no effect on the RGR; (2) the growth rates of deciduous species were greater than those of the evergreen species; and (3) seedling growth rates were increased with more PAR. Our study suggests that above-ground vegetation removal had a stronger effect than trenching on the growth and assembly of tree seedlings in the low-elevation tropical rainforests.
Highlights
Interaction between seedlings is nearly universal in forests
We found that the species are characterized by deciduous species in tropical deciduous monsoon rainforest and by evergreen in the tropical lowland rainforest [16,17,18]
The photosynthetically active radiation (PAR) serves as a proxy for above-ground interactions of plants and the root dry matter mass serves as proxy for below-ground interactions of plants
Summary
Interaction between seedlings is nearly universal in forests. Interactions of plants, can be a critical factor in secondary succession by affecting the speed of forest regeneration [1]. It is true that light is usually the most important factor limiting tree seedling growth in tropical forests [3,4]; below-ground resources are important [5]. The result of both the two types of competition between seedlings and adult trees determines the composition of the advanced renewal and relative growth of the seedlings [6]. Identifying the influences of above- and below-ground interactions of plants on the relative growth of deciduous and evergreen species is necessary to improve our understanding of forest succession
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
