中国科学院水利部水土保持研究所机构知识库

生物土壤结皮（生物结皮）与维管束植物之间的关系一直是生物结皮生态功
能研究的热点问题。目前，国内外相关研究主要明确了不同类型生物结皮对维管
束植物种子萌发、幼苗存活、光合生理、养分运输及群落演替等方面的影响，鲜
有研究关注生物结皮对维管束植物根系的影响，是生物结皮与维管束植物之间关
系研究的空白环节。黄土丘陵区退耕还林（草）工程实施后，生物结皮大面积发
育，是该区退耕地植被恢复演替的关键影响因素。然而，迄今该区生物结皮与维
管束植物之间关系的研究鲜见报道。为此，本文以维管束植物根系为切入点，首
先通过室内试验，研究了黄土丘陵区不同类型及强度干扰的生物结皮对维管束植
物种子萌发、幼苗根系的影响；进而通过明确生物结皮对土壤理化属性的影响，
探究不同类型及强度干扰的生物结皮对维管束植物成株根系特征的影响；在此基
础上，基于冗余分析、逐步回归和通径分析等统计分析，研究了生物结皮对维管
束植物根系的影响方式及程度，以及干扰生物结皮对植物群落特征的影响，解析
了“生物结皮—土壤—根系—维管束植物群落”的联动机制，为该区生物结皮影响
下的草地植被恢复和群落演替提供科学依据。取得的主要结论如下：
（1）生物结皮是维管束植物种子萌发和幼苗存活的关键影响因子，影响方
式与程度与二者之间的相对位置、生物结皮类型、生物结皮的完整性以及维管
束植物种子形态有关。原状生物结皮显著抑制结皮上（种子位于结皮表面）种
子的萌发和幼苗存活，但促进了结皮下（种子位于结皮下层）种子的萌发和幼
苗存活。干扰破碎生物结皮较原状生物结皮促进结皮上和结皮下的种子萌发和
幼苗存活。
①相对位置：裸土上种子萌发率为28.75-70.63%，幼苗存活率为24.38-61.88%，
原状生物结皮上种子萌发率和存活率小于10.00%，显著低于裸土。②结皮类型：
藻结皮较裸土显著促进结皮下白羊草（Bothriochloa ischaemum (L.) Keng）和苜
蓿（Medicago sativa）种子的萌发，萌发率分别提高34.50%和62.33%。藻结皮
显著促进结皮下苜蓿幼苗存活，较裸土及其它结皮提高7.69-107.34%。不同类型
生物结皮均显著提高结皮下长芒草（Stipa bungeana Trin.）幼苗存活率，较裸土

The relationship between biologic soil crusts (biocrusts) and vascular plants has been
a hot topic in the study of the ecological function of biocrusts. At present, the main
research on the effect of biocrust type on the vascular plants was focused on, like
seeds germination, seedlings survival, photosynthetic physiology, nutrient transport
and plant community succession. Few studies were focused on the effect of biocrusts
on the vascular plant roots. There is an obvious knowledge gap in the relationship
between biocrusts and vascular plants. Biocrusts have extensively developed in the
Hilly Loess Plateau region since the implementation of “Grain for Green” ecological
project. Their coverage of biocrust could reach as high as 60~70%, which was the key
influencing factor of vegetation restoration succession in this area. However, there
were few researches on the relationship between biocrusts and vascular plants in this
area so far. To this end, in the view of root system of vascular plants, firstly, the paper
studied the effects of different types and disturbance intensity of biocrusts on seeds
germination and seedlings root system of vascular plants in loess hilly regions.
Secondly, by clarifying the effects of biocrusts on the soil physical and chemical
properties, the effects of different types and disturbance intensity of biocrusts on the
root characteristics of vascular plants were explored. The mode and degree of the
effects of biocrusts on vascular plants root were studied. And the internal mechanism
of "biocrusts—soil—root—plant community” was resolved. We also discussed the
influence of vascular plants root system on plant community by the disturbed
biocrusts. It will provide a scientific basis for vegetation restoration and plant
community succession in the Loess Plateau. The main conclusions are as follows.
(1) Biocrust was a key influencing factor for seeds germination and
seedlings survival of vascular plants, and the influence pattern and degree were
related to the relative position of biocrusts and plant seeds, biocrusts types,
integrity of biocrusts and morphological characteristics of vascular plant seeds.
The seeds germination and seedlings survival were significantly inhibited by the