Precipitation is the most crucial factor determining the distribution of moso bamboo in Mainland China

Peijian Shi,Haiganoush K Preisler,Brady K Quinn,Jie Zhao,Weiwei Huang,Alexander Röll,Xiaofei Cheng,Huarong Li,Dirk Hölscher

doi:10.1016/j.gecco.2020.e00924

Abstract

Moso bamboo is widespread in natural forests and is cultivated over large areas in China. This study investigated how climate controls its distribution, about which little is known. We collected moso bamboo presence-absence data from 674 sites with long-term climate data in Mainland China. Generalized additive models that included location and climate variables were used to test the effects of these predictors on the species’ occurrence. We identified the best model as the one with the lowest Akaike’s Information Criterion value that contained only statistically significant predictors. We found precipitation, especially the mean (APRE) and interannual standard deviation (SDPRE) of the annual precipitation at each site, rather than temperature, to be the main factors determining the distribution of moso bamboo in Mainland China. In addition, we found that there was a significant power law relationship between the mean and interannual variance of precipitation, which made it possible to make long-term predictions. The SDPRE in climate scenarios of changes in the APRE could then be calculated using the fitted power law relationship. We simulated six climate scenarios, in which the APRE increased/decreased by 25, 50, and 75%. We used the 0.5 and 0.9 probability contour lines of model predictions to represent the suitable and core distributions, respectively, of moso bamboo under each scenario. The current core distribution of moso bamboo in Mainland China predicted by our model agreed with actual observations. Our model suggested that the middle and lower reaches of the Huaihe River Plain in eastern China should be climatically suitable for the growth of moso bamboo; it seems likely that its current absence there has resulted from intensive land use. Our model predicted that changes in APRE can strongly alter the distribution of moso bamboo. Increased APRE would expand the core distribution of moso bamboo into southern Shandong Province and over all of Chongqing and most of Guizhou Provinces, which are areas not currently in the species’ core distribution. Conversely, decreased APRE would shrink the core distribution of moso bamboo to the junction of Anhui, Fujian, Jiangxi, and Zhejiang Provinces. We showed that the current distribution of moso bamboo is mainly determined by annual precipitation rather than temperature. The deviations between the moso distributions predicted by the climate model and the current distribution in some plain areas might have resulted from human activities. Future changes in annual precipitation will probably change the distribution of moso bamboo considerably.

Highlights

We found that the minimum annual temperature and annual precipitation data of 72.1 and 76.3% of sites, respectively, passed the normality test
The odds of moso bamboo occurrence rapidly increased with increasing SDPRE from 0 to 120 mm, and the effect of increasing SDPRE on moso bamboo occurrence tended to be constant above 120 mm (Fig. 2E)
Location variables, including longitude, latitude, and altitude, significantly affected the distribution of moso bamboo and accounted for a further half of the explained deviance in these data, it is not necessary to consider their influence under climate change scenarios due to the fact that climate change does not lead to large changes in terrain on a centenary scale

Summary

Introduction

Moso bamboo grows and produces biomass quickly, and it can exclude most tree species to form forests dominated by this single species (Fukushima et al, 2015). In southern China, the establishment of plantations of pure moso bamboo forests (i.e., single species-dominated forests or monocultures) was advocated by local governments in the 1980s to increase the incomes of farmers in mountainous areas (Cheng et al, 2015). The original trees growing in such areas were cut down to promote the propagation of moso bamboo. This plant quickly dominates vacant patches resulting from human disturbance because of its efficient and complex underground rhizome system, which can efficiently prevent other woody plants from regenerating. In a bamboo forest without human disturbance the bamboo population density will increase, but mean individual biomass will decrease through self-thinning (Liu et al, 2016)

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Discussion

Conclusion