Understanding mechanisms of successful colonization by exotic plant species in non-native habitat is critical to meet long-term restoration aims. Previous studies demonstrated that overgrowing plants can alter resources, especially soil inorganic nitrogen availability and get benefits from positive feedback. However, comprehensive knowledge on particular mechanisms underlying their successful colonization remains unclear.
Soil ecology group researchers Dr. Haifeng Xiao and Prof. Xiaodong Yang combined field examinations and laboratory manipulations to investigate significant impact of overgrowing Ageratina adenophora on soil NO3–-N availability and nitrification. Interestingly, they found significant enhancement in soil total N, NO3–-N, pH, potential nitrification rates, and ammonia oxidizing bacteria (AOB), while reduced abundance of ammonia oxidizing archaea (AOA) under the influence of A. adenophora. Notably, AOB abundance was positively correlated with both pH and soil potential nitrification rates. AOA abundance was negatively correlated with pH and had no significant correlation with soil nitrification potential. Both AOA and AOB communities significantly differed between populated and non-populated soils. It is worth mentioning here that pH was the strongest factor contributing to this community difference. Results also showed that A. adenophora has strong long-term preference for nitrate which can further increase soil pH. Their data clearly helps to gain insight into a probable mechanism indicating that A. adenophora stimulates nitrification with the help of AOB rather than AOA under relatively higher soil pH condition.
This study, titled:pH drives ammonia oxidizing bacteria rather than archaea thereby stimulate nitrification under Ageratina adenophora colonization, was published in international journal “Soil Biology & Biochemistry”. This work was supported by the CAS 135 program (XTBG-T01), CAS “Light of West China” Program and the National Science Foundation of China (NSFC) grant (31200409).
Fig. 1. (a) A. adenophora populated area, (b) nonpopulated area nearby.
On June 1, 2017, Mr LIN Xiao-bing successfully finished his master thesis defense with title of The effect of different rubber plantation on termite community structure and diversity distribution in Xishuangbanna. His study explored the effects of rubber plantation on termite community structure and diversity. The results showed that after the natural forest changed to rubber plantation, the diversity and rare species composition of termites significantly decreased, and also termite feeding group changed greatly.
During 20th-26th, February, 2017, Professor Yang with Professor Peng Yan-qiong, Lin Lu-xiang and other collegues visited Forest College in Kasetart University, Suranaree university of science and technology, and Mo Singto 30-ha forest dynamic plot and discussed cooperation issue in 2017. And interviewed a student from Foresty college in Kasetsart University for Master Degree in Soil Ecology Group, XTBG, CAS.
During 21th-24th, December, 2016, Professor Yang and Doctor Xia visited Professor He xin-hua’s research group and Zhang zhi-shen’s research group in Southwest University. Discussed cooperation potential for mycorrhizal fungi study and soil animal study.
On November 30, 2016, Doctor Marc-André SELOSSE, work in Muséum national d’Histoire naturelle, visited Soil Ecology Group and have a short chat with all soil group collegues and students. Professor Yang given a presentation about SEG. SELOSSE was interested in soil biota study of longitude 101 climate gradient plots and discussed cooperation potential in future.
On afternoon of 14th November, Florian Maderspancher, Senior editor of Current Biology, visited Soil Ecology Group(SEG). Xiaodong Yang introduced recent works in SEG to Florian. Florian show interesting in spider and rubber plantation. And also impressed by diversity of colleagues in SEG.
Hope SEG have a chance to publish some work in Current Biology!
Xiaodong Yang introduce rently work of SEG
Part of SEG members photo with Florian Maderspacher
From 12th to 29th October, Soil Ecolog Group(SEG) successfully conducted field soil sampling at Liangjiang Forest Dynamic Plot. To systematically analysis soil food webs and above-below ground interactions, we systematically sampled 660 soils and corresponding litter(humus) samples in plot based on geostatistic principle. Then we clearly disposed samples for analysis of soil nutrient, soil animal, soil microbe and soil nametodes. This activity was coorperate with Lijiang Alpine Botanical Garden. Here we sincerely thanks Professor Kun Xu and Hua Huang and other colleagues in Lijiang Alpine Botanical Garden.
Glimpses of study plot
Equipment to grilled worms
Extract NH4N and NO3N in field
Extraction of nematodes
Professor Xin-Hua He visited Soil Ecology Group in 27th-30th July. Xin-Hua He is a professor in The University of Western Australia, and also Professor in College of Resources and Environment, Southwest University. He mainly focus on mycorrhizal network and proposed hypothesis and proven that plant can bi-directional transport nitrogen through mycorrhizal network.
During visiting, Professor Xin-Hua He introduced how to conduct experiments for mycorrhizal network nutrient transformation, Hai-Feng Xiao and Shang-Wen Xia also introduced our works conducted now in Soil Ecology Group. Professor Xiao-Dong Yang and Professor Xin-Hua He discussed the how to cooperate to conduct mycorrhizal study in Xishuangbanna in future.
During 8th-20th July, the 5th CTFS-CBio workshop successfully organized by Research Institute of Tropical Forestry, Chinese Academy of Forestry in Jianfengling, Hainan. Shangwen Xia attended the workshop. And given two oral presentations “Fine-scale spatial structure of nematodes and their relationship to trees in a tropical rainforest” and “Effect of biotic driven soil heterogeneity on seedling niche differentiation”.
Sincerely thanks Straut J Davies and other CTFS colleagues for helps, and also Luxiang Lin and Han Xu for helps.
Group photo
Photo with respectable Stephen P. Hubbell
