The fate and distribution pattern of atmospheric nitrogen deposition in legume-dominant forests revealed

The fate and distribution pattern of atmospheric nitrogen deposition in legume-dominant forests revealed

The fate and distribution pattern of atmospheric nitrogen deposition in leguminous-dominant forests are revealed

Under the support of the National Natural Science Foundation of China's key and general projects, the Chinese Academy of Sciences Youth Innovation Promotion Association and the Ecology Young Talents Support Project, Dr.
Mao Jinhua from the Ecological Center of the South China Botanical Garden of the Chinese Academy of Sciences, etc.
under the guidance of associate researcher Zheng Mianhai and researcher Mo Jiangming , Revealing the fate and distribution pattern of atmospheric nitrogen deposition in the legume dominant forest
.

Related research was recently published in "Global Change Biology"

Chinese Academy of Sciences

Human activities cause an increase in atmospheric nitrogen deposition, which in turn affects the structure and function of forest ecosystems
.

The impact of nitrogen deposition on the forest ecosystem depends on the whereabouts of the deposited nitrogen

At present, research on the characteristics of nitrogen cycle in legume forests focuses on the characteristics of nitrogen fixation and the rate of nitrogen fixation.
The retention capacity of legume forests for other external input nitrogen (such as atmospheric nitrogen deposition) is still unclear, which limits our effect on atmospheric nitrogen deposition.
And accurate assessment of the nitrogen budget of terrestrial ecosystems
.

In addition, leguminous nitrogen-fixing plants are widely distributed in "nitrogen-rich" tropical forests.

The researchers used the long-term (10-year) nitrogen deposition plot in Heshan, Guangdong Province as the experimental platform, and selected leguminous plantations ( Acacia auriculiformis ) and non- leguminous forests ( Eucalyptus urophylla ) as the experimental objects, and carried out the ecosystem-scale ¹⁵ N for the first time.
Mark the experiment
.

Through a one-year continuous spraying of ¹⁵ NH ₄ ¹⁵ NO ₃ , the retention and distribution patterns of external input nitrogen (atmospheric deposition nitrogen and nitrogen addition) in different components of the two forests were compared

Acacia auriculiformis Eucalyptus urophylla ^{15 15} ₄ ¹⁵ ₃

The study found that “nitrogen-rich” legume forests still have high retention potential for atmospheric nitrogen deposition, and the total ¹⁵ N recovery rate of legume forest ecosystems is significantly higher than that of non-legume forests
.

Mineral soil is the main sink of atmospheric nitrogen, but there is no significant difference in soil recovery rate between the two forests

^{15 15}

The results of the study show that “nitrogen-rich” legume forests have a high retention potential for atmospheric nitrogen deposition, and legume tree species play a major role in the ecosystem's interception of exogenous nitrogen
.

The study emphasized the necessity of including legume-dominant forests into the Earth system nitrogen cycle model to accurately assess the ecological effects of global nitrogen deposition on terrestrial ecosystems

Mao Jinhua, the first author of the paper, said that since most previous studies believed that nitrogen is an important element for the synthesis of phosphorus-acquisition enzymes (phosphatase, etc.
), the results of this study revealed that the higher nitrogen retention capacity of legume forests is helpful to understand "nitrogen-rich and lack of nitrogen".
The "paradox" phenomenon of the widespread distribution of leguminous tree species in the tropics of "phosphorus"
.

(Source: China Science News, Zhu Hanbin, Zhou Fei)

Related paper information: https://doi.

https://doi.
org/10.
1111/gcb.
16005