Delayed Flowering in Bamboo: Evidence from Fargesia qinlingensis in the Qinling Mountains of China.

Wei Wang,Brian J Rude,Scott B Franklin,Zhijun Lu

doi:10.3389/fpls.2016.00151

Abstract

Gregarious flowering of bamboo species impacts ecosystem properties and conservation, but documentation of these periodic events is difficult. Here, we compare the characteristics of flowering sites and un-flowered patches of an arrow bamboo (Fargesia qinlingensis) in the Qinling Mountains, China, over a 5-year period (2003–2007) after a mast flowering event (2003). We examined flowering culm and seedling characteristics in relation to questions regarding the evolution of delayed flowering. Density of live culms decreased over the 5 years in both flowering sites and un-flowered patches. New shoots regenerated only in un-flowered patches. Chemical constituent allocation varied among culm parts (stems, branches, and leaves). Crude protein and extract ether in branches and leaves were less in flowering culms than in un-flowered culms. Seedling density was lower than expected based on floret counts, suggesting predation of seeds. Seedling density was significantly greater in flowering sites than in un-flowered patches and decreased over time. Seedlings performed better in flowering sites than in un-flowered patches based on their height, leaf number per seedling, and average leaf length, while fertilization on flowering sites had no significant effect on seedling growth, suggesting a saturation of resources. This study suggested that the characteristics of bamboos and bamboo stands were dramatically altered during this flowering event, enhancing seedling establishment and growth, and supporting mostly the habitat modification hypothesis of delayed reproduction.

Highlights

Many bamboo species are semelparous, having an unusual life history including a long clonal growth phase, followed by mass synchronous flowering and subsequent death (Janzen, 1976; Tian, 1987; Qin et al, 1989; Taylor et al, 1991)
We examined changes of stand structure, seed bank dynamics and seedling regeneration, and culm characteristics/energy allocation during a flowering event of Fargesia qinlingensis T.P
Dynamics of Density and Characteristics of Culms No new shoots regenerated from rhizomes in the flowering sites during the five studied years

Summary

Introduction

Many bamboo species are semelparous, having an unusual life history including a long clonal growth phase (sometimes over 100 years), followed by mass synchronous flowering and subsequent death (Janzen, 1976; Tian, 1987; Qin et al, 1989; Taylor et al, 1991). Delayed Flowering in Bamboo (Franklin, 2004; Nath and Das, 2010), but sporadic die-off events result in the loss of habitat and diversity (Sertse et al, 2011) for several years threatening endangered species like the giant panda (Tian, 1987). Bamboo flowering events are linked to heterospecific tree species and forest regeneration patterns (Kitzberger et al, 2007; Caccia et al, 2009; Montti et al, 2014; Caccia et al, 2015). X. Shao in order to better understand the biology of gregarious-flowering, semelparous long-lived bamboos, and subsequently manage for habitats of endangered species following die-offs (Nath and Das, 2010)

Objectives

Methods

Results

Discussion

Conclusion