ISWC OpenIR  > 水保所知识产出(1956---)
黄土丘陵沟壑区优势植物对不同侵蚀环境的 适应 研究 —— 从群落、个体、组织到生理
杜 华 栋
Subtype博士
Thesis Advisor焦菊英
2013-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword群落组成 叶片解剖 枝系构型 繁殖策略 抗逆生理 黄土高原
Abstract

黄土高原严重的土壤侵蚀,造成了该区梁峁起伏、地形破碎、立地环境复杂多变,
使得水、热等生态因子的空间分布存在异质性,形成了多样的侵蚀环境。植物随着生长
环境的改变,在群落组成、生殖策略、形态结构、生理特性上不断的调整来适应相应的
环境。本文通过陕北黄土丘陵沟壑区 3 个植被带(森林带、森林草原带、草原带)坡沟
系统中 5 种不同侵蚀环境下(阳沟坡、阳峁坡、峁顶、阴峁坡、阴沟坡)植物群落组成
的调查,分析群落中各物种的生态位宽度和重要值,据此筛选出不同侵蚀环境下的优势
物种。研究了九种优势植物(猪毛蒿、铁杆蒿、茭蒿、白羊草、长芒草、芦苇、达乌里
胡枝子、杠柳、狼牙刺)在不同侵蚀环境下的繁殖、形态、解剖和生理响应特征,并从
中选取了 4 种枝系构型植物(聚丛型铁杆蒿、疏丛型茭蒿、簇丛型白羊草、主杆型狼牙
刺),研究了其对坡面微环境的影响。主要研究结果如下:
(1)由森林带向草原带过渡,植物群落结构变的简单,物种多样性减小,但物种个
数反而有增加趋势;中生植物、高位芽植物减少,旱生植物、隐芽植物增加。坡沟系统
不同侵蚀环境下物种均匀度差异不显著,但阴坡群落物种多样性和丰富度较阳坡提高;
阳沟坡旱生植物和隐芽植物比例大;而峁顶一年生植物比例增大。从阳沟坡至阴沟坡随
着侵蚀程度的减小,物种数量和密度增加,但各物种生态位宽度和重要值减小。旱生和
旱中生植物在黄土丘陵沟壑区有着广泛的分布。
(2)同种植物单个花序(花)重、单个种子重量表现出一定的遗传稳定性,在坡沟
系统不同侵蚀环境下差异不明显。阳沟坡和阴沟坡植物有性生殖投入低,但该侵蚀环境
下隐芽植物比例大,使得其上物种主要以芽库完成地上植被更新。峁顶和阳峁坡植物有
性生殖投入量大,产生大量的种子有利于植物种群的扩大。相对其他供试物种,达乌里
胡枝子有性繁殖分配比例大,而两种灌木狼牙刺与杠柳则相反。在芽库季节动态上,植
物返青期较大的永久性芽库存量保证了植物迅速更新,开花结实期大量季节性芽库确保
了植物光合产物积累。
(3)同种植物叶片形态解剖结构在 3 个植被带相同坡沟侵蚀环境下变化差异性不显
著,但坡沟系统不同的侵蚀环境下植物叶片形态和解剖结构变化差异明显。随着侵蚀程
度的增加,叶片叶片厚度、干物质量积累、角质层厚度、栅栏组织厚度、木质部韧皮部面积比增加,叶面积、表皮细胞大小、海绵组织厚、细胞间隙减小。输送水分的木质部
与植物适应环境能力关系密切。不同植物适应黄土高原半干旱的气候也有不同的策略:
猪毛蒿叶具有发达贮水组织,铁杆蒿全栅型叶片,茭蒿和狼牙刺具有双栅型叶片和大的
维管束鞘细胞,达乌里胡枝子叶具有发达的粘液细胞,白羊草和芦苇叶上表皮具有发达
的泡状细胞,长芒草叶上表皮下多层厚壁组织,杠柳厚的角质层。综合隶属函数分析表
明,叶片保护组织发达的长芒草从叶片形态与解剖角度分析对环境适应能力最强。
(4)三个植被带相同坡沟侵蚀环境下植物叶片生理特性变化未达到显著性,但坡
沟系统不同侵蚀环境下植物叶片生理特性差异明显。从阴沟坡至阳沟坡随着侵蚀程度增
加,细胞受伤害和叶绿素受破坏程度增加,但植物通过叶片保水力、渗透调节物质、抗
逆酶活性、非酶抗氧化物质的加强来应对环境胁迫,同时减小叶片相对含水量、自由束
缚水比值,以牺牲植物生长速率的代价来应对胁迫环境。所测生理指标中,与植物环境
适应相关性最大的是抗坏血酸氧化酶。隶属函数综合分析表明两种灌木杠柳和狼牙刺从
生理角度分析对环境适应性较强。
(5)不同构型植物拦截坡面径流沉积物和保护植冠下土体而形成不同形态的土堆。
随着坡度的增加,土堆由对称堆型圆帽结构转变为不对称的台阶型结构,主杆型狼牙刺
转折点在 15-25°的陡坡,聚丛型铁杆蒿和簇丛型白羊草在 26-35°的极陡坡,疏丛型茭
蒿在≥36°的险坡。坡度和植丛顺坡基部直径影响着土堆的高度;而植丛垂直坡面的基
部直径、植丛分枝数量及整个植丛的冠幅影响着土堆的面积。随着坡度的增加土堆高度
总体上呈增加趋势而土堆面积趋势相反。植物拦截形成的土堆成为坡面的“营养岛”,
相对于植被间表现出良好的土壤理化特性及较高的物种多样性。茭蒿以其发达且扩张的
枝系、狼牙刺以其较大的植冠在形成土堆和对坡面微环境的改善方面能力较强。
(6)在繁殖策略方面,供试物种猪毛蒿、铁杆蒿、茭蒿、白羊草、杠柳趋向于 r-
生殖策略,长芒草、达乌里胡枝子、狼牙刺更趋向于 K-生殖策略。依据植物适应环境
时的形态解剖与生理特点,供试植物可分为Ⅰ:御逆型,猪毛蒿、芦苇、长芒草;Ⅱ:
胁变修复型,茭蒿、白羊草、达乌里胡枝子;Ⅲ:御胁变型,铁杆蒿、狼牙刺、杠柳。
综合植物繁殖、形态、解剖和生理特征,供试物种综合隶属函数值与物种重要值呈正相
关关系,供试植物的侵蚀环境适应能力表现为:两种灌木狼牙刺和杠柳较强,在黄土丘
陵沟壑区不同侵蚀环境有着广泛分布的铁杆蒿、达乌里胡枝子、长芒草次之,而对侵蚀
环境具有选择性的白羊草、茭蒿、芦苇和猪毛蒿相对较小。
关键词:群落组成;叶片解剖;枝系构型;繁殖策略;抗逆生理;黄土高原

Other Abstract

The serious soil erosion on the Loess Plateau cause the deep cut gullies, fragmentation of
landform and form a complicated landform, thus result in spatial heterogeneity of water and
heat. Then, there are series of adjustments occur on plant community structure, reproductive
strategies, leaf morphological and physiological characteristics to adapt different soil
environments. In this study, the community structures in five soil erosion environments on
slope-gully system (sunny gully slope, sunny hilly slope, hilltop, shady hilly slope, and shady
gully slope) on three vegetation zones (forest zone, forest-steppezone, and steppe zone) on the
hilly-gully region of the Loess Plateau were examined. The species niche breadth and
important value in community were analysed to identify dominant species at different soil
erosion environments. The reprodution, morphology, anatomy, and physiology of seclected
nine dominant species (Artemisia scoparia, Artemisia gmelinii, Artemisia giraldii,
Bothriochloa ischcemum, Stipa bungeana, Phragmites australis, Lespedeza davurica,
Periploca sepium and Sophora davidii) were studied. And, four typical shoot architecture
species (A. gmelinii, with dense shoot architecture; A. giraldii, with expanding shoot
architecture; B. ischaemum, with a tussock-formingshoot architecture; and S. viciifolia, with a
main-stem shoot architecture) was selected to analysis the shape of phytogenic mounds and
its influence of mirco-environmnent on slope. The main results are as follows:
(1) Fom forest to steppe zone, plant community structures become simple, species
diversity decreased, and the number of species showed a slight increased with mesophytes
and phanerophytes decreased, while xerophytes and cryptophytes increased. At different soil
erosion environments on slope-gully system, the variation of species evenness was not
significant. On shady slope, the species diversity and richness were relative larger than sunny
slope. The xerophyte and cryptophytes increased at sunny gully slope. Hilltop had a higher  therophyte proportion than the other erosion environments. From sunny to shady gully slope,
the species niche and important value in community decreased with the decreasing of erosion
degree. Xerophyte and xero-mesophytes have a wide range of distribution on the hilly-gully
region of the Loess Plateau.
(2) For same species, single dry weight of inflorescence (flower) and seed mass showed
certain genetic stability, and no significant difference existed in different soil erosion
environments on slope-gully system. At the sunny gully slope and shady gully slope, plant
reproductive investment was low, but the high proportion of cryptophytes on these
environments made vegetation regeneration relying mainly on bud bank. The reproductive
investment of species on hilltop and sunny hilly slope were larger than the other three erosion
environments which result in a large number of seeds and thus was beneficial to the expansion
of seed dispersal plants. L. davurica had a larger reproductive allocation, while two shrubs (P.
sepium and S. davidii) were relatively less. In vegetation turning-green season, the larger
perennial bud bank ensure a rapid vegetation renewal. The larger seasonal bud bank on
fruit-setting season ensure the accumulation of photosynthate.
(3) The leaf morphological and anatomical characteristics at same slope-gully erosion
environment on the three vegetation zones had a slight changes, but these characteristics
showed significant changes at different erosion environments on slope-gully system. With the
increasing of soil erosion degree, leaf thickness, dry matter content, cuticle thickness, palisade
tissue thickness, xylem area/phloem area increased, while leaf area, epidermal cell size,
spongy tissue thickness, intercellular space decreased. In those leaf morphological and
anatomical indices, xylem area, which mediate plant water transportation, had the closest
relationship with plant environmental adaptability. Different plants have its special structure
to adapt the semi-arid climate on the Loess Plateau: water storage parenchyma of A. scoparia,
total-palisade tissue of A. gmelinii, bi-palisade tissue and big bundle sheath cells of A. giraldii
and S. davidii, mucilage cell of L. daurica; special bulliform cells of B. ischcemum and P.
australis; multilayer sclerenchyma of S. bungeana; thick cuticle of P. sepium. From leaf
morphological and anatomical characteristics, comprehensive analysis of the subordinate
function showed that S. bungeana, which has a well developed protective tissues, had the
strongest environmental adaptability.
(4) Similar to plant morphological characteristics, plant physiological indices at same
slope-gully erosion environment on the three vegetation zones showed a slight changes, but
those characteristics presented significant changes at different erosion environments on slope-gully system. From sunny to shady gully slope,with the increasing of soil erosion
degree, the degree of cell damage and amount of chlorophyll destruction increased. But plant
resistance to environmental stress by increasing leaf water-holding ability, osmotic adjustment
substances, stress-resistance enzymes, non-enzymatic antioxidants, meanwhile by decreasing
leaf relative water content and free water/bound water. This processes are at the expense of
plant growth rate to deal with the environmental stress. Among the 21 measured physiological
indices, ascorbic acid oxidase (APX) had the closest relationship with plant environmental
adaptability. From plant physiological indices, comprehensive analysis of the subordinate
function showed that two testing shrubs, S. davidii and P. sepium, had a strong environmental
adaptability.
(5) Different shoot architecture species have different ability of preventing soil erosion
and retaining sediment, thus the shape of phytogenic mound changes with slope gradient
increasing. Mound shapes changed from symmetrical mound-type structures into
asymmetrical terrace-type structures as slope gradient increased, but the change at 0-15°for
S. viciifolia, at 26-35°for A. gmelinii and B. ischaemum, at >35°for A. giraldii. Among the
plant shoot architecture parameters, plant basal diameter along the slope was significantly
correlated with mound height, while the plant basal diameter perpendicular to the slope and
total cross-sectional area of the stem at the plant base were associated with mound area.
Mound height increased with slope for all species, while mound area showed opposite
tendency. The phytogenic mounds can act as ‘resource islands’, thus improved species
richness and stress resistance of plant community on slope. A. giraldii with expanding shoot
architecture and S. viciifolia with its large canopy can create relatively large mounds.
(6) In reproductive strategy, K-reproductive strategyare adopted by A. scoparia, A.
gmelinii, A.giraldii, B. ischcemum and P. sepium; and r-reproductive strategy by S. bungeana,
L. davurica and S. davidii. According to the palnt anatomical and physiological characteristics
of environmental adaptation, the testing plants were divided into three types: I, stress
avoidance, including A. scoparia, S. bungeana and P. australis; II, strain repair, including A.
giraldii, B. ischcemum and L. davurica; III, strain avoidance, A. gmelinii, P. sepium and S.
davidii. Integrative subordinative value was calculated based on reproductive, morphological,
anatomical and physiological characteristics of plant. The integrative subordinative values of
testing plants on different soil erosion environments of slope-gully system were positively
correlated with the species important value in community. From the results of comprehensive
analysis of the subordinate function, two shrubs, S. davidii and P. sepium, showed higher  environmental adaptability than another testing plants, followed by widespread plants (A.
gmelinii, L. davurica, S. bungeana), the environmental adaptability of B. ischcemum, A.
giraldii, P. australis, A. scoparia which only distributed on certain erosion environments,
were relatively weak among testing plants.
Key words: community composition; leaf anatomy; plant shoot architecture; reproductive
strategy; stress-resistance physiology; Loess Plateau

Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8976
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
杜 华 栋. 黄土丘陵沟壑区优势植物对不同侵蚀环境的 适应 研究 —— 从群落、个体、组织到生理[D]. 北京. 中国科学院研究生院,2013.
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