@article{Crous_Drake_Jacobsen_Pratt_Jacobs_Esler_2019, title={Foliar nitrogen dynamics of an invasive legume compared to native non-legumes in fynbos riparian zones varying in water availability}, volume={45}, url={https://watersa.net/article/view/6686}, DOI={10.4314/wsa.v45i1.12}, abstractNote={<p>The legume <em>Acacia mearnsii</em> invades South Africa’s fynbos riparian zones and may alter the nitrogen (N) dynamics and supply in these areas that typically support few native N fixers. Nitrogen uptake by <em>A. mearnsii</em> may also be influenced by water availability, potentially affecting riparian-specific performance and impact estimations. We expected to find functional differences between the invasive legume and the two co-occurring but non-leguminous native species <em>Brabejum stellatifolium</em> and <em>Metrosideros angustifolia</em>. We also wanted to examine whether in-situ water availability affected N source or uptake in<br>the invasive species. We found <em>A. mearnsii</em> was indeed functioning differently from non-N-fixing native species, and had considerably higher foliar %N. Interestingly,<sup> 15</sup>N abundance and uptake were associated with site hydrology, meaning water availability should be scrutinised when assuming N-fixing in <em>A. mearnsii</em> using δ<sup>15</sup>N. Nonetheless, higher water availability to<em> A. mearnsii</em> in fynbos riparian ecosystems did increase foliar N uptake. This has implications for prioritizing clearing of sites with increased nutrient deposition, such as dense stands in relatively moist riparian zones.</p>}, number={1 January}, journal={Water SA}, author={Crous, Casparus J and Drake, Deanne C and Jacobsen, Anna L and Pratt, R Brandon and Jacobs, Shayne M and Esler, Karen J}, year={2019}, month={Jan.} }