5. CONCLUSIONS
In summary, our findings indicate that inter-annual precipitation
fluctuation, rather than nutrient addition or AM fungal suppression,
determines ANPP and plant species composition in desert steppe in the
Northwest China. Furthermore, we also found that annual plant species in
plant communities are more sensitive to precipitation than are other
plant species, particularly in dry years. Therefore, we recommend that
interactions among annual precipitation, fertilisation and AM fungi be
incorporated into grassland management models when evaluating desert
steppe ecosystem responses. Finally, our study indicate that the
responses of plant communities in arid grassland to soil nutrient
enrichment and symbiotic fungi vary over time. Unfortunately, our study
was carried out across only two growing seasons with contrasting
precipitation patterns, which limits our ability to understand plant
community dynamics under various rainfall scenarios in the long term.
Therefore, further studies are obliged to examine whether the responses
of plant communities to nutrients input and AM fungi are consistent over
longer periods.