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Response of aboveground biomass and diversity to nitrogen addition along a degradation gradient in the Inner Mongolian steppe, China.

Xu X, Liu H, Song Z, Wang W, Hu G, Qi Z - Sci Rep (2015)

Bottom Line: Fields with a higher level of degradation tended to have a higher saturation value (20 g N m(-2) yr(-1)) than those with a lower degradation level ( < 10 g N m(-2) yr(-1)).After three years of experimentation, species richness showed little change across degradation levels.Among the four functional groups of grasses, sedges, forbs and legumes, grasses shared the most similar response patterns with those of the whole community, demonstrating the predominant role that they play in the restoration of grassland under a stimulus of nitrogen addition.

View Article: PubMed Central - PubMed

Affiliation: College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, 100871, China.

ABSTRACT
Although nitrogen addition and recovery from degradation can both promote production of grassland biomass, these two factors have rarely been investigated in combination. In this study, we established a field experiment with six N-treatment (CK, 10, 20, 30, 40, 50 g N m(-2) yr(-1)) on five fields with different degradation levels in the Inner Mongolian steppe of China from 2011-2013. Our observations showed that while the external nitrogen increased the aboveground biomass in all five grasslands, the magnitude of the effects differed with the severity of degradation. Fields with a higher level of degradation tended to have a higher saturation value (20 g N m(-2) yr(-1)) than those with a lower degradation level ( < 10 g N m(-2) yr(-1)). After three years of experimentation, species richness showed little change across degradation levels. Among the four functional groups of grasses, sedges, forbs and legumes, grasses shared the most similar response patterns with those of the whole community, demonstrating the predominant role that they play in the restoration of grassland under a stimulus of nitrogen addition.

No MeSH data available.


Response of species richness to the nitrogen addition. AF = abandoned farmland, ED = extremely degraded grassland, SD = severely degraded grassland, MD = moderately degraded grassland, MG = mature grassland. Bars with the same letter (e.g., a, b) were not significantly different in tests of S-N-K.
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f4: Response of species richness to the nitrogen addition. AF = abandoned farmland, ED = extremely degraded grassland, SD = severely degraded grassland, MD = moderately degraded grassland, MG = mature grassland. Bars with the same letter (e.g., a, b) were not significantly different in tests of S-N-K.

Mentions: The plant species richness among the five experimental fields was quite different, but did not differ significantly among N-treatment. After three years, different trends began to appear in the slopes, although these differences were quite small. Species richness increased in the ED and MD but decreased in the MG and SD with increasing N-treatment, though changes in species richness were not significant in any sites except MG (Fig. 4).


Response of aboveground biomass and diversity to nitrogen addition along a degradation gradient in the Inner Mongolian steppe, China.

Xu X, Liu H, Song Z, Wang W, Hu G, Qi Z - Sci Rep (2015)

Response of species richness to the nitrogen addition. AF = abandoned farmland, ED = extremely degraded grassland, SD = severely degraded grassland, MD = moderately degraded grassland, MG = mature grassland. Bars with the same letter (e.g., a, b) were not significantly different in tests of S-N-K.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4508527&req=5

f4: Response of species richness to the nitrogen addition. AF = abandoned farmland, ED = extremely degraded grassland, SD = severely degraded grassland, MD = moderately degraded grassland, MG = mature grassland. Bars with the same letter (e.g., a, b) were not significantly different in tests of S-N-K.
Mentions: The plant species richness among the five experimental fields was quite different, but did not differ significantly among N-treatment. After three years, different trends began to appear in the slopes, although these differences were quite small. Species richness increased in the ED and MD but decreased in the MG and SD with increasing N-treatment, though changes in species richness were not significant in any sites except MG (Fig. 4).

Bottom Line: Fields with a higher level of degradation tended to have a higher saturation value (20 g N m(-2) yr(-1)) than those with a lower degradation level ( < 10 g N m(-2) yr(-1)).After three years of experimentation, species richness showed little change across degradation levels.Among the four functional groups of grasses, sedges, forbs and legumes, grasses shared the most similar response patterns with those of the whole community, demonstrating the predominant role that they play in the restoration of grassland under a stimulus of nitrogen addition.

View Article: PubMed Central - PubMed

Affiliation: College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, 100871, China.

ABSTRACT
Although nitrogen addition and recovery from degradation can both promote production of grassland biomass, these two factors have rarely been investigated in combination. In this study, we established a field experiment with six N-treatment (CK, 10, 20, 30, 40, 50 g N m(-2) yr(-1)) on five fields with different degradation levels in the Inner Mongolian steppe of China from 2011-2013. Our observations showed that while the external nitrogen increased the aboveground biomass in all five grasslands, the magnitude of the effects differed with the severity of degradation. Fields with a higher level of degradation tended to have a higher saturation value (20 g N m(-2) yr(-1)) than those with a lower degradation level ( < 10 g N m(-2) yr(-1)). After three years of experimentation, species richness showed little change across degradation levels. Among the four functional groups of grasses, sedges, forbs and legumes, grasses shared the most similar response patterns with those of the whole community, demonstrating the predominant role that they play in the restoration of grassland under a stimulus of nitrogen addition.

No MeSH data available.