Assessment of regeneration potential in the clonal macrophyte Miscanthus sacchariflorus (Poaceae) after burial disturbance based on bud bank size and sprouting capacity.

Xinsheng Chen,Yonghong Xie,Zhengmiao Deng,Xu Li,Chenshu Cao,Feng Li,Zhiyong Hou,Kurt O Reinhart

doi:10.1371/journal.pone.0120846

Xinsheng Chen, Yonghong Xie + Show 6 more

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https://doi.org/10.1371/journal.pone.0120846

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Abstract

The demography of the bud bank and its sprouting capacity are important for understanding the population dynamics of clonal plants and their potential responses to disturbances. To this end, we investigated the size and composition of the bud bank of Miscanthus sacchariflorus (Maxim.) Hack. immediately after flooding (November), in winter (January), in spring (March), and before flooding (May) in the wetlands of Dongting Lake. We then examined the sprouting capacity of axillary buds after sediment burial at 0, 5, 10, 15, and 20 cm. Total bud density of M. sacchariflorus ranged from 2524 buds m-2 in November to 4293 buds m-2 in March. Rhizome segments with inactive axillary buds, which represented the majority of the bud population (88.7% in November, 93.3% in May), did not sprout during the 140 days of the experiment (n = 250). The sprouting ratio was the highest for active axillary buds buried at 0 cm (64%) and decreased when buried at 10–20 cm (34%–40%). Due to the large number of active axillary buds in the bud bank (211–277 buds m-2 from November to the following March), M. sacchariflorus could completely replace its aboveground shoot population, except in May (142 buds m-2). Increasing burial depth delayed bud emergence and reduced the growth period of shoots; however, burial depth did not affect the resulting plant height and only reduced the accumulated biomass at 20 cm. Therefore, the belowground bud bank and its strong sprouting capacity are important factors in the maintenance of local populations and colonization of new habitats for M. sacchariflorus after burial disturbances. The present methodology, which combined measurements of bud bank demography and sprouting capacity, may reflect the regeneration potential of clonal plants after burial disturbances.

Highlights

Clonal plants are widespread across all biomes and biogeographical regions, in cold, wet, shaded, and nutrient-poor environments [1]
We investigated the size, composition, and seasonal dynamics of the bud bank of M. sacchariflorus in the wetlands of Dongting Lake, where this species usually forms tall, monospecific stands that cover 751 km2 of the wetland area [18]
The density of apical buds collected in January (75 ± 13 buds m-2) was significantly higher than that of apical buds collected in March (25 ± 5 buds m-2) (Fig. 1A)

Summary

Introduction

Clonal plants are widespread across all biomes and biogeographical regions, in cold, wet, shaded, and nutrient-poor environments [1]. Most perennial clonal plants possess the capacity of both sexual reproduction through seeds and vegetative propagation through bud banks [1, 2]. Bud number fluctuates over the course of a year due to the developmental stages of the parent plants and environmental factors limiting plant growth [5,6,7, 9]. These seasonal changes in the bud bank make vegetative regeneration sensitive to the timing of disturbance [10, 12]. It is important to determine the size of the bud bank at different times for understanding the population dynamics of clonal species and their potential responses to disturbance [12]

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Conclusion