Species and spatial differences of vegetation rainfall interception
capacity - a synthesis and meta-analysis in China
Abstract
China has carried out many ecological restoration projects in the past.
At present, there are large spatial differences in the hydrological
effects of forest ecosystems in different regions of the country under
heterogeneous conditions, which is not conducive to the macro guidance
of ecological restoration projects. Canopy interception is an important
link in the water cycle of the ecosystem. This paper attempts to use
this index as a bridge to connect the research literature of existing
ecological sites, so as to evaluate the differences in water resources
distribution in different regions and vegetation ecosystems and analyze
the main reasons for the differences. We combined canopy interception
rate (I0) and canopy water storage ability (I) to interpret canopy
interception, and collected site related geographic, meteorological and
ecosystem structure information simultaneously in the literature to
build up an original dataset. Analysis on the database showed that the
comprehensive interception capacity of vegetation in the south was
generally higher than that in the north, which was dominated by shrubs,
and that the tree species had interception advantages. Mixed forest
showed the best comprehensive interception capacity, while pure tree
forest had better interception potential than shrubbery due to its
biomass advantage. The actual interception capacity of shrubbery was
better than pure tree forest due to the advantages of stand density and
the dry climate. Results from the evaluation of canopy interception
ability using different indexes were not consistent, meaning that
evaluating canopy interception with multiple indexes may be more
objective. The study also highlights that the current structural
characteristics of shrubby forests in northern China may be
counterproductive to mitigating drought, reducing the structural density
of a given stand will increase the opportunity for precipitation to
reach the surface, thereby increasing the amount of water available to
ecosystems in arid areas. Maintaining the healthy growth of mixed
forests is still the right choice for humid areas in the south.