Effect of drought and nutrient availability on invaded plant communities in a semi‐arid ecosystem

• Published in: Ecology and evolution Vol. 12; no. 9; pp. e9296 - n/a
• Main Authors: Ali, Hamada E., Bucher, Solveig Franziska
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01-09-2022; John Wiley and Sons Inc
• Subjects: Arid environments; Aridity; Availability; Biomass; Competition; Diameters; Drought; Dry matter; Ecosystems; Environmental impact; Flowers & plants; Functionals; global change; Global Change Ecology; Grasslands; Hypotheses; Indigenous species; Introduced species; invasion success; invasive plant species; Invasive plants; Invasive species; Leaf area; Leaves; Morphology; Native species; Nitrogen; Nonnative species; Nutrient availability; Performance assessment; Plant communities; plant functional traits; Plant populations; Plant species; Plants; Plants (botany); Success; Egypt; invasion success; plant functional traits; global change; invasive plant species
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.9296

Ecosystem functions are heavily dependent on the functional composition of the plant community, i.e., the functional traits of plants forming the community. This, on the one hand, depends on plant occurrence, but on the other hand, depends on the intraspecific variability of functional traits of the species, which are influenced by climate and nutrient availability and affected by plant–plant interactions. To illustrate that, we studied the effects of drought and nitrogen addition (+ N), two important abiotic variables which are changing with ongoing global change, as well as their combined effect on the functional responses of grassland communities in semi‐arid environments of Northern Africa comprising of natural and invasive species. We conducted an experiment where we planted three native species and one invasive plant species in artificial communities of five individuals per species per plot. We exposed these communities to four different treatments: a drought treatment, an N‐addition treatment, the combination between drought and N‐addition, as well as a control. To assess the performance of plants within treatments, we measured selected plant functional traits (plant height, specific leaf area [SLA], leaf dry matter content [LDMC], N content of the leaves [Nmass], specific root length [SRL], and root diameter) for all individuals occurring in our plots, and additionally assessed the above and belowground biomass for each plant individual. We found that the invasive species showed a higher performance (higher biomass accumulation, taller plants, higher SLA, Nmass, SRL, and root diameter as well as lower LDMC) than the native species under drought conditions. The invasive species was especially successful with the combined impact of drought + N, which is a likely scenario in ongoing global change for our research area. Thus, plant functional traits might be a key factor for the invasion success of plant species which will be even more pronounced under ongoing global change.
Climate, nutrient availability, and invasive plants are major threats to ecosystems. The study measures the invasion success of Imperata cylindrica under climate change and nitrogen application. The study found that the invasion success increased under drought conditions. This invasion success was promoted by plant functional traits.