Study on the life historical strategy of an early successional species (Penthorum chinense) for restoration

Abstract

Translocation into new habitats is an essential way to conserve rare plant species. The common failure of this effort stems predominantly from unsuitable new habitats. I performed a field survey and mesocosm experiments in order to understand the realized niche, fundamental niche, and tolerance to environmental conditions of Penthorum chinense for the successful translocation of the sandy riparian rare plant, P. chinense. Environmental range for the distribution of P. chinense is characterized by a relatively low degree of succession (9.02~1031), high percent photosynthetically active radiation (11.94~100 %), low contents of soil organic matter (0.89~4.38 %), NO3-N (0.04~12.61 mg kg−1), and PO4-P (0.75~28.42 mg kg−1), much sand (13.85~94.98 %) among the soil texture classes, and low water depth or watersides (-9~7 cm) with a wide range of water content from waterlogged soils to dry soils of the water-level-fluctuation zone. All the individual plants survived, grew, and reproduced both asexually and sexually under all treatments except extreme low light (ELL) group. In addition, the seed number and final germination percentage of P. chinense did not drastically decrease, even during severe stress except low light (LL) group in our experiment. The result indicated that P. chinense has a narrow realized niche which requires oligotrophy and disturbance, even though the fundamental niche of the soil nutrient and water content appears to be large. Also, P. chinense showed a variety of traits tolerant to nutrient deficit, drought, waterlogging, and submergence of 15 days. The restricted distribution of P. chinense to low-productive peripheral habitats might be a strategy to reduce competition for light, which occurs frequently with other rare plant species as well, and P. chinense has the strategies to increase survival in habitats that have alternate occurrences of flooding and drought. Here, I suggest that P. chinense be translocated to sandy soils that include gravel in waterside environments or shallow waters with periodic flooding, where low nutrients and water holding capacity cause reduction in the competitors performance

on the other hand, P. chinense has the ability to tolerate these conditions. I believe that my research could be a good starting point for study of the translocation of rare plants to suitable sites.