Estimating Crown Structure Parameters of Moso Bamboo: Leaf Area and Leaf Angle Distribution

Xuhan Wu,Xiaojun Xu,Weiliang Fan,Feilong Huang,Hongli Ge,Huaqiang Du

doi:10.3390/f10080686

Abstract

Both leaf area (LA) and leaf angle distribution are the most important eco-physiological measures of tree crowns. However, there are limited published investigations on the two parameters of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz., abbreviated as MB). The aim of this study was to develop allometric equations for predicting crown LA of MB by taking the diameter at breast height (DBH) and tree height (H) as predictors and to investigate the leaf angle distribution of a MB crown based on direct leaf angle measurements. Data were destructively sampled from 29 MB crowns including DBH, H, biomass and the area of sampled leaves, biomass of total crown leaves, and leaf angles. The results indicate that (1) the specific leaf area (SLA) of a MB crown decreases from the bottom to the top; (2) the vertical LA distribution of MB crowns follow a “Muffin top” shape; (3) the LA of MB crowns show large variations, from 7.42 to 74.38 m2; (4) both DBH and H are good predictors in allometry-based LA estimations for a MB crown; (5) linear, exponential, and logarithmic regressions show similar capabilities for the LA estimations; (6) leaf angle distributions from the top to the bottom of a MB crown can be considered as invariant; and (7) the leaf angle distribution of a MB crown is close to the planophile case. The results provide an important tool to estimate the LA of MB on the standing scale based on DBH or H measurements, provide useful prior knowledge for extracting leaf area indexes of MB canopies from remote sensing-based observations, and, therefore, will potentially serve as a crucial reference for calculating carbon balances and other ecological studies of MB forests.

Highlights

As “the major non-wood forest product and wood substitute”, bamboo is widely distributed in tropical, subtropical, and warm, temperate regions between 46◦ N and 47◦ S, which covers a total area of 31.47 million hectares, accounting for 0.78% of the global forest area [1]
The results indicate that (1) the specific leaf area (SLA) of a MB crown decreases from the bottom to the top; (2) the vertical LA distribution of MB crowns follow a “Muffin top” shape; (3) the LA of MB crowns show large variations, from 7.42 to 74.38 m2 ; (4) both diameter at breast height (DBH) and H are good predictors in allometry-based LA estimations for a MB crown; (5) linear, exponential, and logarithmic regressions show similar capabilities for the LA estimations; (6) leaf angle distributions from the top to the bottom of a MB crown can be considered as invariant; and (7) the leaf angle distribution of a MB crown is close to the planophile case
The results provide an important tool to estimate the LA of MB on the standing scale based on DBH or H measurements, provide useful prior knowledge for extracting leaf area indexes of MB canopies from remote sensing-based observations, and, will potentially serve as a crucial reference for calculating carbon balances and other ecological studies of MB forests

Summary

Introduction

As “the major non-wood forest product and wood substitute”, bamboo is widely distributed in tropical, subtropical, and warm, temperate regions between 46◦ N and 47◦ S, which covers a total area of 31.47 million hectares, accounting for 0.78% of the global forest area [1]. In Asian countries, bamboo forests have been expanding rapidly for the past 50 years [2]. China possesses the largest bamboo forest with an area of more than 6.01 million hectares, which accounts for approximately 2.97% of the total forested area nationally [3]. The area of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz., abbreviated as MB) has reached 4.43 million hectares, which is 73.71% of the bamboo forested area in. Characterized by fast growth and strong carbon sequestration abilities, MB forests show great potential to be a substantial carbon sink and, play a significant role in addressing global climate change [4,7,8,9,10,11]

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