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Table 2 Summary of factors favouring each strategy

From: Strategies of offspring investment and dispersal in a spatially structured environment: a theoretical study using ants

Parameter Expectations Outcomes of simulations
Increase expected to favour Basis of expectation Single strategy Two-strategy Follows predictions?
DCF ICF Low High
Life-history
 Longevity Colonizer Equation 6 ++ +++ ICF ICF Y
 Maintenance cost Unclear a DCF ICF na
 Maximum growth rate Colonizer Equation 6 none + DCF ICF Y
 Maturity threshold None Equation 6 DCF ICF na
 Reproductive investment Unclear b + ++ DCF ICF na
Environ.
 Disturbance Colonizer Tilman DCF ICF Y
 Resources Colonizer Equation 6 +++ ++ ICF DCF N
 Aggregation Competitor c + ICF DCF Y
  1. The predictions of increasing the parameter of interest, and basis for this prediction, are given in the first two columns (see main text). The single-strategy columns indicate the influence of the parameter on the abundance of each strategy, with increasing positive or negative effect indicated by increasing number of ±symbols. The dominating strategy at high and low parameter values under competition conditions is given in the two-strategy columns. The final column notes whether results followed the predictions (see “Results”). Tilman refers to Eq. 4.1 in Tilman [33]
  2. aEquation 6 predicts increasing maintenance costs will exacerbate differences in competitive ability thus favouring DCF, but increasing maintenance cost will also lead to more colonization opportunities by decreasing overall occupancy (see also main text)
  3. bEquation 6 predicts that DCF competitiveness is favoured by increasing asymmetry in propagule size (i.e., increasing reproductive investment) but ICF will also be advantaged through increased colonization ability from increased number of propagules [33, eq. 4.1]
  4. cHigher habitat aggregation is expected to favour the competitive strategy as increasing aggregation leads to increasing probability of dispersal to good patches for the low disperser, while colonizers disperse equally to good and bad habitat irrespective of their aggregation. This is a novel characteristic of our spatially explicit model