Tensile fracture properties of seven tropical grasses at different phenological stages
Tensile fracture properties of seven tropical grasses at different phenological stages
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DOI：
10.1111/j.1365-2494.2011.00812.x
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发表时间：
2011-12
影响因子：
2.4
通讯作者：
A. Jacobs;J. Scheper;M. Benvenutti;I. Gordon;D. Poppi;A. Elgersma
中科院分区：
文献类型：
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作者：
A. Jacobs;J. Scheper;M. Benvenutti;I. Gordon;D. Poppi;A. Elgersma
放牧反刍动物对牧草的采食量与牧草的力学断裂特性密切相关。在由茎和叶组成的热带生殖草中，草的拉伸断裂特性与觅食行为之间的关系尤为重要。本研究(1)量化并比较了7种热带禾本科植物茎秆和叶片的拉伸断裂特性；(2)深入了解了解释不同物种间断裂特性差异的潜在植物性状。对5种引进的热带禾草（Cenchrus ciliaris、Chloris gayana、Digitaria milanjiana、Megathyrsus maximus （syn. Panicum maximum）、Setaria sphacelata）和2种本地热带禾草（Setaria surgens和Dichanthium sericeum）的茎（在不同物候阶段）和叶片的断裂力、拉伸强度、断裂能和韧性进行了测定和比较。不同物种在断裂力和断裂能方面存在显著差异，其中，毛菖蒲和刺菖蒲的茎叶断裂所需的力和能量较小，而刺菖蒲和棘菖蒲的茎叶断裂所需的力和能量较大。拉伸强度和韧性的差异不太明显。不同树种间断裂力和断裂能的差异主要是由于植物部位截面积的差异，而非抗拉强度和韧性的差异。
The intake of forage grasses by grazing ruminants is closely related to the mechanical fracture properties of grasses. The relationship between the tensile fracture properties of grasses and foraging behaviour is of particular importance in tropical reproductive swards composed of both stems and leaves. This study (i) quantified and compared the tensile fracture properties of stems and leaves of seven tropical grass species and (ii) provided insight into the underlying plant traits that explain differences in fracture properties between species. Fracture force, tensile strength, fracture energy and toughness of stems (in various phenological stages) and leaves were measured and compared among five introduced tropical grasses (Cenchrus ciliaris, Chloris gayana, Digitaria milanjiana, Megathyrsus maximus (syn. Panicum maximum), Setaria sphacelata) and two native tropical grasses (Setaria surgens and Dichanthium sericeum). Species differed significantly in fracture force and fracture energy, with stems and leaves of C. ciliaris and S. surgens requiring less force and energy to fracture and stems and leaves of M. maximus and S. sphacelata requiring more force and energy to fracture in comparison with the other species. Differences in tensile strength and toughness were less pronounced. The differences among species in fracture force and energy mainly resulted from differences in cross-sectional area of plant parts rather than from differences in tensile strength and toughness.