水保所知识产出(1956---)知识库

黄土高原地区退耕还林还草工程实施后，以藻类、苔藓及地衣等先锋物种为主的生
物结皮广泛发育，有关其中物种组成及多样性鲜见报道。本文通过野外考察、采样、室
内培养和种类鉴定， 研究了黄土高原不同环境下生物结皮中蓝藻门植物的
Shannon-Weiner 多样性指数、物种丰富度、优势种及生物量，对比了不同环境下蓝藻门
植物多样性特征，以及水分、温度的变化对蓝藻物种组成及多样性特征的影响，探索了
蓝藻在不同环境下时空分布差异的内在原因，旨在进一步理解黄土高原不同侵蚀区藻类
的固土效应、藻结皮形成演替机制以及藻类在该区生态恢复中的作用，为生物结皮在水
土流失及荒漠化防治中的应用提供科学依据。本文首次分析了黄土高原生物结皮中蓝藻
的种类组成、多样性、时空分布特征以及时空分布的影响因素。取得如下主要结论：
1）黄土高原地区生物结皮中共发现蓝藻门植物5 目5 科13 属76 种，存在明显的
科属现象，优势科为颤藻科，优势属为颤藻属，其中丝状种类约占87%，占绝对优势。
研究区蓝藻植物隶属科属有：色球藻科(Chroococcaceae)、伪枝藻科(Scytonemataceae)、
胶须藻科(Rivulariaceae)、颤藻科(Oscillatoriaceae)和念珠藻科(Nostocaceae)，色球藻属
(Chroococcus)、集胞藻属(Synechocystis)、单歧藻属(Tolypothrix)、伪枝藻属(Scytonema)、
尖头藻属(Raphidiopsis)、束藻属(Symploca)、鞘丝藻属(Lyngbya)、颤藻属(Oscillatoria)、
席藻属(Phormidium)、微鞘藻属(Microcolus)、念珠藻属(Nostoc)、鱼腥藻属(Anabaena)。
2）研究区蓝藻植物多样性指数水蚀风蚀交错区 > 水蚀区 > 风蚀区，生物量水蚀
风蚀交错区 > 水蚀区 > 风蚀区。蓝藻多样性指数在同一侵蚀区阴坡大于阳坡，同一坡
向随坡位降低逐渐升高。剖面上，蓝藻多样性随土层深度锐减，蓝藻主要分布在0-2cm
土层，0-0.5cm土层的蓝藻种类占全部土层蓝藻种类的85%，0-2cm土层占总蓝藻种类的
98%；2cm以下土壤中蓝藻种类很少。不同侵蚀区蓝藻Shannon-Weiner多样性指数表现
为：水蚀风蚀交错区 > 水蚀区 > 风蚀区，依次为2.22 bit，2.20 bit和2.14 bit，水蚀风
蚀交错区和水蚀区蓝藻多样性指数差异不显著（P>0.05），但均与风蚀区差异显著
（P<0.05）。蓝藻丰富度及优势种在不同侵蚀区也各不相同，水蚀风蚀交错区蓝藻丰富
度最高（39种），以阿氏鞘丝藻(Lyngbya allorgei)为优势种；水蚀区次之（26种），以含钙席藻(Phormidium calciola)为优势种；风蚀区最低（20种），以颗粒颤藻(Oscillatoria
granulata)为优势种。与蓝藻多样性指数的变化趋势一致，藻类的生物量在不同侵蚀区表
现为：水蚀风蚀交错区>水蚀区>风蚀区。在同一侵蚀区，阴坡蓝藻多样性指数大于阳坡；
同一坡向随坡位的降低表现出逐渐升高的趋势，其中，阴坡的蓝藻多样性指数随坡位的
降低表现为坡上2.57 bit < 坡中2.67 bit< 坡下2.69 bit。阳坡的多样性指数与阴坡略有不
同，随坡位的降低表现为坡中2.46 bit < 坡上2.54 bit < 坡下2.65 bit；阳坡和阴坡的蓝藻
优势种分别为狭细席藻(Phormidium angustissimum)和阿氏鞘丝藻(Lyngbya allorgei)。剖
面上，蓝藻主要分布在0-2 cm土层，0-0.5 cm土层的蓝藻种类占全部土层蓝藻种类的85%，
0-2 cm土层占总蓝藻种类的98%；蓝藻多样性随土层深度锐减，2 cm以下土壤中蓝藻种
类很少。其中，0-0.5 cm土层的蓝藻多样性均极显著高于其下层（P<0.01），0.5-1 cm 土
层与下层1-2 cm、2-5 cm之间的差异均达显著水平（P<0.05），其余土层之间的差异均不
显著（P>0.05）。
3）蓝藻植物多样性随着发育年限及季节变化，表现出明显的年际和年内动态特征。
随着退耕年限的增长，多样性指数呈上升的趋势，至发育8a以上的，其多样性逐渐稳定；
年内蓝藻多样性指数雨季中>雨季前>雨季末。
研究区蓝藻多样性指数农地(CK)最低2.08 bit，退耕20a以上最高2.65 bit，其多样性
指数与农地之间的差异均达显著水平（P<0.05），退耕8a以上与退耕0.5a的其蓝藻多样性
指数之间均差异显著（P<0.05）。不同发育年限的生物结皮中蓝藻的丰富度中，农地最
低（21种），退耕8a最高（32种）。退耕0.5a这段时期是蓝藻的快速增长期，退耕8a的生
物结皮中蓝藻丰富度达到最高。不同季节的蓝藻Shannon-Weiner物种多样性指数表现为：
雨季中>雨季前>雨季末，依次为2.96 bit，2.85 bit和2.66 bit。雨季中与雨季末多样性指
数差异显著（P<0.05），其余差异不显著（P>0.05）；蓝藻的丰富度与多样性指数的变化
趋势一致，雨季中最高（35种），雨季前（32种）次之，雨季末（26种）最少。雨季前
和雨季中的生物结皮中蓝藻的优势种分别为狭细席藻和阿氏鞘丝藻，雨季末的优势种与
雨季前相同。然而，藻类的生物量的季节变化为雨季前>雨季中>雨季末。
4）蓝藻植物多样性与环境水分、温度变化有关。降水量与蓝藻多样性指数及丰富
度之间呈正相关关系，是影响蓝藻多样性的首要环境因子。温度对蓝藻多样性影响次之。
与蓝藻多样性相关的土壤理化属性有土壤全氮，土壤全磷和土壤速效磷。其中，土壤全
氮与蓝藻多样性之间呈极显著负相关关系。土壤全磷和速效磷与蓝藻多样性均呈显著负
相关关系。不同的蓝藻对环境因子的响应不同，具有不同的生态适应性。
关键词：蓝藻；多样性；时空分布；环境因子；影响因素

Biological soil crust (biocrusts) that constituted by pioneer organismes such as algae,
cyanobacteria, mosses and lichens extensively developed in the Loess Plateau region after the
“Grain for Green” eco-project was implementated in the region. So far, studies on species
composition and distribution of cyanobacteria in the biocrusts in the Loess Plateau region were
fresh. In the paper, diversity charecteristic of cyanophytes was studied in biocrusts under different
environment conditions on the Loess Plateau region. Cyanobacteria in the biocrusts from the
Loess Plateau region was cultured, observed and identified. In addition, we analyzed
Shannon-Weiner diversity index, species richness, dominant species and biomass in the biocrusts
under field and laboratory conditions so as to determine the influencing factors of the
temporal-spatial distribution characteristics of cyanophytes. The paper was aimed at
understanding ecological restoration effects of cyanophytes further, including soil fixation and
succession mechanism in this region, also providing the scientific evidence for soil and water
erosion as well as desertification control. As far as our knowledge, the paper was the one of the
earliest studies on diversity characteristic of cyanophytes in the Loess Plateau region. The main results
are as follows.
(1) We found 76 species of cyanophytes in the biocrusts of the Loess Plateau region,
which belongs to 13 genera and 5 families. In the study area, dominant familiy and genus
were evident which were Oscillatoriaceae and Oscillatoria, respectively. Filamentous
cyanobacteria were the dominant species in cyanophytes which accounted for 87%. Families
and genera were Chroococcaceae, Scytonemataceae, Rivulariaceae, Oscillatoriaceae, Nostocaceae
and Chroococcus, Synechocystis, Tolypothrix, Scytonema, Raphidiopsis, Symploca, Lyngbya,
Oscillatoria, Phormidium, Microcolus, Nostoc, Anabaena.  (2) In the study area, Shannon-Weiner diversity index of cyanobacteria and algae
biomass were ranged in the order of water-wind erosion crisscross region > water erosion
region > wind erosion region. In same erosion region, Shannon-Weiner diversity index of
cyanobacteria on the shady slopes were greater than that on the sunny slopes, while
Shannon-Weiner diversity index gradually ascended from higher to lower positions on the
same aspect. In the soil profiles, Shannon-Weiner diversity index of cyanobacteria were
decresing against the increase of soil depth, dominanted cyanobacteria species were mainly
in the 0-2 cm layers and seldom exist in the lower layers. Futhermore, cyanobacteria species
in the 0-0.5 cm layer accounts for 85% of that in all layers. In different erosion regions,
Shannon-Weiner diversity index of cyanobacteria presented as that: water-wind erosion crisscross
region > water erosion region > wind erosion region, they were 2.22 bit, 2.20bit and 2.14bit
separately. No significant difference was found between the cyanobacteria diversity of
water-wind erosion crisscross region and water erosion regions, while diversity in the wind
erosion region was significantly lower than that in the water erosion region or that in the
wind-water crisscross erosion region. In addition, richness and the dominant species were
different in the three erosion regions. Cyanobacteria richness was greatest (39) in the water-wind
erosion crisscross region, followed by the water erosion region (26) and the wind erosion region
(20). The dominant cyanobacteria species in the water-wind erosion crisscross region, water
erosion and wind erosion region were Lyngbya allorgei, Phormidium calciola and Oscillatoria
granulate, respectively. Variation trend of algal biomass were the same as that of Shannon-Weiner
diversity index in the three erosion regions. Dominant cyanobacteria species on the shady slpoes
and the sunny slopes were Phormidium angustissimum and Lyngbya allorgei, respectively. In soil
profiles, Cyanobacteria diversity showed descending trend with the increase of soil depth,
dominant cyanobacteria species are mainly in the 0-2 cm layers and seldom exist in lower layers,
among them, cyanobacteria species in the 0-0.5 cm layer accounts for 85% of that in all layers.
(3) Cyanophyte diversity was influenced by the age of development and the seasons.
Shannon-Weiner diversity index were increasing before stabilizing with years of biocrusts
development, when the age of development was over 8 years, Shannon-Weiner diversity
index were gradually stable. Shannon-Weiner diversity index of cyanobacteria should be
ranged in the order of rain season > before rain season > after rain season. In the area,
significant differences were found in Shannon-Weiner diversity index between other years of  development and farmland. Among richness of cyanobacteria in different years of biocrusts,
cyanobacteria richness in 8 years of biocrusts was the highest, and that in farmland was lowest.
The first half year of development was the fastest growth stage of cyanobacteria. Shannon-Weiner
diversity index in different seasons were showed as rainy season > before rainy season > after
rainy season, they were 2.96 bit, 2.85 bit and 2.66 bit, separately; Shannon-Weiner diversity index
of cyanobacteria at rainy reason was significantly higher than those after rainy season. The
variation trend of cyanobacteria richness at different seasons was in accordance with that of
Shannon-Weiner diversity index, they were 35, 32 and 26. Dominant cyanobacteria species before
rainy season was Phormidium angustissimum, which was the same with that after rainy season,
Lyngbya allorgei was the dominant species in the rainy season. Algae biomass was showed in the
ranged of before rainy season > rainy season > after rainy season.
(4) Cyanophyte diversity was related to moisture and tempreture of the environment.
The result showed that precipitation was the prime and vital influencing factor on the
diversity of Cyanophyte. There was a negative correlation between precipitation and
Shannon-Weiner diversity index and richeness of Cyanophyte. Tempreture was the second
most important factor. The correlation analysis indicated that soil total nitrogen and phosphorus
and available phosphorus were relevant to diversity of cyanobacteria, among them, diversity of
cyanobacteria has a significantly negative correlation with soil total nitrogen, but a significantly
negative correlation with soil total phosphorus and available phosphorus. Different cyanobacteria
species influenced by different environment facters have different ecological suitability.
Keywords: Diversity, cyanophyte, temporal-spatial distribution, environment factors, influencing
factors