caa a22 4500 46316864X CHVBK 20180406164807.0 cr unu---uuuuu 170326e20070301xx s 000 0 eng 10.1007/s10530-006-0008-3 doi (NATIONALLICENCE)springer-10.1007/s10530-006-0008-3 Functional Group Identity Does not Predict Invader Impacts: Differential Effects of Nitrogen-fixing Exotic Plants on Ecosystem Function [Elektronische Daten] [Stephanie Yelenik, William Stock, David Richardson] The introduction of exotic plants can have large impacts on ecosystem functions such as soil nutrient cycling. Since these impacts result from differences in traits between the exotic and resident species, novel physiological traits such as N cycling may cause large alterations in ecosystem function. It is unclear, however, whether all members of a given functional group will have the same ecosystem effects. Here we look at a within functional group comparison to test whether an annual (Lupinus luteus) and a perennial (Acacia saligna) N-fixing exotic species cause the same effects on soil N cycling in the fynbos vegetation of South Africa. We measured litterfall quantity and quality, and soil total nitrogen and organic matter for each vegetation type as well. Available nitrogen was quantified using ion exchange resin bags monthly for 1year. We used microcosms to evaluate litter decomposition. Although both exotic species increased the available nitrogen in the soil, only Acacia increased the total soil N and organic matter. This could be explained by the slow decomposition of Acacia litter in the microcosm study, despite the fact that Acacia and Lupinus litter contained equivalent N concentrations. Presumably, low carbon quality of Acacia litter slows its decomposition in soil, resulting in retention of organic nitrogen in Acacia stands after clearing for restoration purposes. The differences in long term impacts of these annual and perennial species highlight the fact that not all N-fixing exotic species exert equivalent impacts. Ecologists should consider multiple traits rather than broadly defined functional groups alone when predicting invader impacts. Springer, 2006 Acacia saligna nationallicence available soil nitrogen nationallicence exotic plants nationallicence fynbos nationallicence litter decomposition nationallicence Lupinus luteus nationallicence organic soil nitrogen nationallicence South Africa nationallicence Yelenik Stephanie Institute for Plant Conservation, University of Cape Town, 7701, Rondebosch, South Africa aut Stock William Botany Department, University of Cape Town, 7701, Rondebosch, South Africa aut Richardson David Institute for Plant Conservation, University of Cape Town, 7701, Rondebosch, South Africa aut Biological Invasions Kluwer Academic Publishers 9/2(2007-03-01), 117-125 1387-3547 9:2<117 2007 9 10530 https://doi.org/10.1007/s10530-006-0008-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10530-006-0008-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yelenik Stephanie Institute for Plant Conservation, University of Cape Town, 7701, Rondebosch, South Africa aut NATIONALLICENCE 700 1- Stock William Botany Department, University of Cape Town, 7701, Rondebosch, South Africa aut NATIONALLICENCE 700 1- Richardson David Institute for Plant Conservation, University of Cape Town, 7701, Rondebosch, South Africa aut NATIONALLICENCE 773 0- Biological Invasions Kluwer Academic Publishers 9/2(2007-03-01), 117-125 1387-3547 9:2<117 2007 9 10530 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer