Remotely sensed plant traits can provide insights into ecosystem impacts of plant invasions: a case study covering two functionally different invaders

Biological flora of Central Europe: Impatiens glandulifera Royle

“…This is likely caused by the high amounts of biomass produced by the invader itself, which was found to be 7.98 ± 4.58 kg m -² SD wet biomass and 0.58 ± 0.32 kg m -² SD dry biomass across fifteen 0.75 m 2 areas of densely invaded riparian vegetation in Belgium (Van Meerbeek et al, 2015). Along an invasion gradient in Belgium total aboveground biomass nonetheless decreased (Van Cleemput et al, 2020b). Invader-induced increases in total biomass were furthermore related to both functional traits of I. glandulifera and CWM traits of the invaded communities (Helsen et al, 2018a;Van Cleemput et al, 2020b).…”

“…Along an invasion gradient in Belgium total aboveground biomass nonetheless decreased (Van Cleemput et al, 2020b). Invader-induced increases in total biomass were furthermore related to both functional traits of I. glandulifera and CWM traits of the invaded communities (Helsen et al, 2018a;Van Cleemput et al, 2020b). Belowground (root) biomass, however, was strongly reduced following invasion, potentially due to allelopathic effects (see part 5.10) (Gaggini et al, 2019b).…”

“…The shading effects are also reflected in the community weighted mean (CWM) functional trait shifts towards higher SLA and lower LDMC (Hejda, 2013;Hejda and de Bello, 2013;Helsen et al, 2018b;Scharfy et al, 2011). In Belgium, CWM SLA was, however, found to increase with higher abundance of I. glandulifera (Van Cleemput et al, 2020b). CWM plant height was furthermore reduced in the presence of I. glandulifera in a greenhouse experiment (Helsen et al, 2018a).…”

“…Several studies found no effects of I. glandulifera invasion on soil carbon and nutrient levels (Dassonville et al, 2008;Gaggini et al, 2019b;Helsen et al, 2020b), with the exception of increased soil B and Cu in Czech Republic (Čuda et al, 2017b), increased soil P in Belgium (Van Cleemput et al, 2020b) and reduced soil K in Germany (Diekmann et al, 2016). Although no clear difference in litter decomposition rate was observed in Czech Republic (Čuda et al, 2017b), decomposition rates were significantly higher for invaded than control plots along a latitudinal gradient from northern France (Amiens) to central Sweden (Stockholm).…”

Making remote sense of biodiversity: What grassland characteristics make spectral diversity a good proxy for taxonomic diversity?

“…Invasion tends to reduce taxonomic diversity (Vilà et al, 2011), so in order for spectral diversity to be a good proxy of taxonomic diversity, it should also decrease with invasion. However, the addition of non‐native species to a community may disproportionally increase spectral diversity compared to the addition of native species, because non‐native species often exhibit biochemical and structural traits that are quite different from the native vegetation (Funk et al, 2008; Helsen et al, 2020; Van Cleemput et al, 2020). Alternatively, invasion may lead to biotic homogenization (Olden et al, 2004) and hence decreased species turnover, a pattern that we expect to weaken the relationship between taxonomic and spectral diversity (see Moderator 2 in Figure 1).…”