Fight or flight: plastic behavior under self-generated heterogeneity

Abstract

Plants are able to plastically respond to their ubiquitously heterogeneous environments; however, little is known about the conditions under which plants are expected to avoid or confront their neighbors in dense stands, where heterogeneity is selfgenerated by non-uniform growth and feedback between plant interactions and stand heterogeneity. We studied the role of plasticity for spatial pattern-formation and the resulting stand-level fitness of clonal plants, assuming variable types of plastic behavior. Specifically, the adaptive values of behavior ranging from pure avoidance, to neutral and pure confrontation were assessed using a simulation model of stands of clonally growing plants with varying capacity of plastic behavior. The results demonstrated significant effects of the type of competitive behavior on mean final densities of single-species stands at equilibrium. Density was the lowest and aggregation was the highest in stands of purely confrontational plants, and density was highest in stands of neutral and purely avoiding plants. When competing against a neutral photometer (i.e. non-plastic but otherwise identical plant), the best competitors were plants that avoided their neighbors in 0.33-0.50 of the cases and were neutral otherwise. Differences in adaptive values of individual behaviors depended both on the distance over which the environmental structure (i.e. local density) was perceived, and on overall density. Density-independent ramet mortality profoundly changed the effectiveness of competitive behaviors. Under high levels of mortality, avoidance was the most effective and confrontation the least effective behavior.The results indicate that individual-based behaviors might affect higher organizational levels, and that their reciprocal interactions with resource levels and patchiness, and T. Herben (&) Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Průhonice, responsiveness to density-independent mortality might generate higher-order feedbacks that intricately affect the fate of individual ramets and the patterning of whole stands and communities.

New insights from multidimensional trait space responses to competition in two clonal plant species

“…Numerous studies demonstrated that trait plastic responses (Bittebiere, Renaud, Clément, & Mony, 2012;Herben & Novoplansky, 2010;Turkington, Hamilton, & Gliddon, 1991), related to processes of stabilising niche differences or increasing competitive ability (Chesson, 2000;Turcotte & Levine, 2016), depend on competitor identity. In particular for intraspecific competition, a niche differentiation process should limit the competition intensity through horizontal traits plasticity, allowing complementary ramet positioning (Herben, Krahulec, Hadincová, & Pecháčková, 1994).…”

Searching for the Relevance of Clonal and Bud Bank Traits Across Floras and Communities

“…However, research on clonal plant growth has demonstrated that clonal growth is often plastic in response to environment (Novoplansky et al 1990;Hutchings and De Kroon 1994;Skálová et al 1997) and this plasticity can be ecologically relevant (Berg and Ellers 2010;Herben and Novoplansky 2010). Using this line of argumentation, Sammul (2011) examined whether spacer length, or its intraspecific variation, are good explanatory variables for plant distribution in Estonian wooded meadows (subjected to different management regimes and differing in their resource heterogeneity levels).…”

Some plants don’t play games: An ideal free distribution explains the root production of plants that do not engage in a tragedy of the commons game.

“…Thus, it is logical to ask: what rooting strategies lead to the greatest competitive ability and highest returns on fitness? Cahill and McNickle 2011; Herben and Novoplansky 2010; Litav and Harper 1967; Parrish and Bazzaz 1976; Schenk et al 1999; Litav and Harper 1967; Craine et al 2005; Gersani et al 2001, Campbell and Grime 1989; Parrish and Bazzaz 1976; Parrish and Bazzaz 1976; Schenk et al 1999; Hess and de Kroon 2007; Litav and Harper 1967; McNickle et al 2008; Mommer et al 2011; Schenk et al 1999.…”

“…A second group of plant ecologists are skeptical of these game theoretic models of root production (de Kroon et al 2012; Herben and Novoplansky 2010; Hess and de Kroon 2007; Laird and Aarssen 2005; Schenk 2006; Semchenko et al 2007). This skepticism seems to be well founded, and there is evidence that many plants do not engage in these plastic pre-emptive games (Cahill et al 2010; Semchenko et al 2007; Semchenko et al 2010).…”