Plant communities, populations and individuals have distinct responses to short‐term warming and neighbour biomass removal in two montane grasslands

Abstract

Aims: Climate change will impact plant communities and populations but also individual plant performance. Most predictive models of community responses to climate change ignore individual-level biotic interactions despite their known importance for community diversity and functioning. Here, we consider plant fitness and diversity responses to climate change associated factors at three organisational levels: communities, populations and individual plants, to increase our understanding of how plant communities respond to climate change.

Reducing herbicide input and optimizing spray method can minimize nontarget impacts on native grassland plant species

“…Competitive displacement of native species by exotics has been documented in grassland communities elsewhere (Thiele et al, 2010) and how this plays out depends on the traits of the invader as they relate to the resident community (Britton et al, 2021). In our study, exotic forbs responded positively to herbicide spot spraying and, at one location, this appeared to be driven specifically by exotic annuals.…”

“…Thus, even if both groups were similarly impacted, a greater proportion of exotic species groups could have avoided the strong effects of herbicide by chance because of their higher occurrence. Regardless of the underlying mechanism, the competitive effects of invading species might increase as the climate warms by increasing the impact on the individual fitness of resident species (Britton et al, 2021). Any practice that gives exotic species a further competitive edge, such as herbicide appeared to do in this study, should therefore be avoided.…”

Quantifying neighbour effects on tree growth: Are common ‘competition’ indices biased?

“…Thus, growth analyses that incorporate FDIs must be applied with caution or risk incorrectly characterising the true neighbourhood effect. For example, considering absolute growth, the improper use of FDI may lead to an over‐estimate of competitive effects, potentially masking a positive interaction such as facilitation, which is increasingly recognised as a common and important process operating in a range of plant communities (Bertness & Callaway, 1994; Bimler et al, 2018; Britton et al, 2021; Fajardo & McIntire, 2011).…”

The competitive effect of neighbouring plants on the growth of two eucalypts is stronger in dry conditions

“…Thus, interactions among neighbouring plants take a variety of forms and the cumulative effect of all neighbours contributes to the observed growth rate of a given plant (Trinder et al., 2013). Importantly, interactions among neighbouring plants are increasingly recognised as a dynamic process which can vary in strength and direction, such as in response to altered environmental conditions (Bimler et al., 2018; Britton et al., 2021; Del Río et al., 2014). A greater understanding of how neighbour interactions vary temporally in different environmental conditions is required to inform predictive models of neighbour effects on plant growth in future climatic conditions.…”

“…Importantly, interactions among neighbouring plants are increasingly recognised as a dynamic process which can vary in strength and direction, such as in response to altered environmental conditions (Bimler et al, 2018;Britton et al, 2021;Del Río et al, 2014).…”