Greater capacity for division of labour in clones of Fragaria chiloensis from patchier habitats

Abstract

Summary1 Unlike non-clonal plants, clonal plants can develop a division of labour in which connected ramets specialize to acquire different, locally abundant resources. This occurs as a plastic response to a patchy environment where two resources tend not to occur together and different ramets experience high availabilities of different resources. We hypothesized that if division of labour is an important advantage of clonal growth in such environments in nature, then clones from habitats where resource availabilities are negatively associated should show a greater capacity for division of labour than clones from habitats where resource availabilities are more uniform. 2 To test this, we collected clones of Fragaria chiloensis from sand dune and grassland sites in each of three regions of the central coast of California, grew pairs of connected or severed ramets under low light and high N or under high light and low N, and measured leaf area, chlorophyll content and final dry mass. Given that previous work has indicated that high availabilities of light and N show a stronger tendency not to occur together in the dune than in the grassland sites, we expected that clones from dunes would show greater capacity for division of labour than clones from grasslands. 3 Clones from dunes showed a greater capacity than clones from grasslands to specialize for acquisition of abundant N via high proportional mass of roots. Clones from the two types of habitats showed similar capacity to specialize for acquisition of abundant light via high leaf area and chlorophyll content of leaves. Specialization via leaf area and chlorophyll content took place mainly within the first half of the 60-day experiment. 4 These results provide evidence that division of labour in a clonal plant has been selected for in natural habitats where high levels of different resources tend to be spatially separated. Results also show that division of labour can occur, not just via allocation of mass, but also via physiological traits, and that both morphological and physiological specialization can take place within a few weeks. 5 Clonal plants dominate many habitats and include many highly invasive species. Division of labour is one of the most striking potential advantages of clonal growth, and is a remarkable instance of phenotypic plasticity in plants. This study further suggests that division of labour in clonal plants is an instance of adaptive plasticity and could therefore play a part in their widespread ecological success.

Integration in the clonal plant Eriophorum angustifolium: an experiment with a three-member-clonal system in a patchy environment

“…However, higher availability of nitrogen in the N + L-sector might support physiological compensation (Mooney and Winner 1991). Roiloa et al (2007) recently showed that not only biomass investments may be responsible for capturing a limiting resource in clonal plants in a heterogeneous environment, but physiological compensation may play a role as well. Therefore, we can speculate that there can be higher nitrogen concentration or higher concentration of chlorophyll in leaves and physiological plasticity could lead to enhanced photosynthesis in the shaded sector (N + L-).…”

Origin matters for level of resource sharing in the clonal herb Aegopodium podagraria

“…However, under homogeneous resource conditions the benefits of sharing are suggested to decrease or to be turned into a cost (Pitelka and Ashmun 1985;Caracao and Kelly 1991;Alpert 1999). Both theoretical and empirical studies suggest that selection for a higher degree of resource sharing occurs in habitats where resources are heterogeneously distributed, resulting in local adaptation for resource sharing (Alpert 1999;Oborny et al 2000;Alpert et al 2003), or division of labour (Roiloa et al 2007).…”

How internode length, position and presence of leaves affect survival and growth of Alternanthera philoxeroides after fragmentation?

“…When remaining intact, stolon internodes play important roles in clones' foraging responses (Birch and Hutchings 1994;Wijesinghe and Hutchings 1999) and resource sharing (Alpert 1999;Alpert et al 2003), thereby contributing greatly to their fitness (Alpert 1999;van Kleunen and Stuefer 1999;Alpert et al 2003;Roiloa et al 2007;Wang et al 2008;Yu et al 2009). …”