As an important part of the natural ecological asset in China, grasslands have been
severely destructed by the excessively irrational use along with the rapidly growing
economics. Today people have fully noticed the importance of grasslands, and a series of
projects have been constructed to do the protection and rational utilization of the grassland
Based on the emergy value that created by a famous ecologist named Odum , emergy
analysis theory could transform various energys of ecosystem or eco-economic system into
emergy values with a same standard by using the emergy transformity. And through this
mdthod, people can further measure a variety of ecological flows, includeing energy and
materials flow, monetary flow, population flow, information flow, and so on, and obtain a
series of comprehensive analysis indicators of the emergy value, and thus finally
quantitatively analyze the structure and function characteristics and ecological economic
benefits for the system evaluation .
This paper will focuse on the yearly valuation in a span of 31 years (1982-2013) of
typical steppe ecosystem in Yunwu Mountain National Nature Reserve by using the
emergy analysis theory after the enclosure management. And the framework of emergy
method was justified according to the actual situation to explore the feasibility of the
method in valuating natural resources. This paper aims to clarify the value and main
recycling mode in energy and material flowing of grassland ecosystem, and to further
enhance the construction and management of grassland ecosystem.
The main results were as follows:
There was a large rise in the value of typical steppe ecosystem in Yunwu Mountain
National Natural Reserve since the enclosure management had being taken in 1982. Total
ecosystem value was 3.61 billion dollars which included 0.38 billion dollars in ecosystem
service valuation and was far higher than the initial valuation of 0.33 billion dollars, indicating a significant improvement due to the enclosure management.
The value of inputs into grassland ecosystem fluctuated around a line with the
absence of inputs before 2011. Due to the social economic input, the input value had a
significant increase in grassland ecosystem. It reached at 1.70×10 19 sej in 2013, which was
far higher than 0.58×10 19 sej in 2010.
The enclosure managenment made the emergy value of output from the grassland
ecosystem increase yearly, peaking at 9.56×10 19 sej in 1996, and then declined with
different speeds until 2010. Up to now, social economic inputs beginning at 2011 have
made an apparent and significant increase with a value of 1.02×10 19 sej to the output value
of emergy and total value of the grassland ecosystem.
According to the results mentioned above, the enclosure management with a span of
more than thirty years has increased the value of grassland ecosystem significantly. With
the inputs of both natural resources and social economics, the typical steppe in Yunwu
Mountain has developed very well and is turning into a more energetic ecosystem.
Keywords: Emergy ；Value ；Typical steppe ；Ecosystem ；Yunwu Mountain