High Benefits of Clonal Integration in Two Stoloniferous Species, in Response to Heterogeneous Light Environments

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Ecology.Summary 1 In natural habitats, essential resources for plant growth are heterogeneously distributed in space, resulting in environmental patchiness with favourable and less favourable microhabitats. Clonal plants may benefit from their ability to share resources between connected ramets experiencing contrasting levels of resource supply. This hypothesis was tested with clones of Potentilla reptans and P. anserina, consisting of a mother rosette and a number of daughters on an attached stolon, grown under homogeneously high and low light conditions, as well as in spatially heterogeneous light environments in which either mother or daughters were shaded. Biomass data were used to carry out an analysis of the costs and benefits of clonal integration. 2 Both species showed high benefits of integration. In P. reptans, connections to unshaded clone-parts enhanced biomass production of the shaded part. In contrast to the prediction that clonal integration would result in costs to unshaded clone-parts connected to shaded parts, unshaded ramets of both species developed higher instead of lower dry weights when connected to a shaded part. Thus, unshaded ramets actually benefitted from integration. 3 It is hypothesized that these unexpected benefits of integration were due to mutual support of connected clone-parts growing in shaded and unshaded patches. The high evaporative demands of the unshaded clone-parts probably resulted in water being translocated from shaded to unshaded ramets while, at the same time, carbohydrates were translocated from unshaded to shaded ramets. 4 We discuss implications of this suggested bidirectional transport of two different resources for the ecological significance of physiological integration in clonal plants and for the notion of habitat heterogeneity.

Spatial heterogeneity of light and tree sapling responses in the understory of disturbed montane forests

“…This study presents a novel way to quantify at stand level the notion of complementary patches that represent possible temporal and spatial shifts in the balance between the positive and negative effects of microsites (Parrish & Bazzaz 1985, Stuefer et al 1994, Stuefer 1996, Hutchings & Wijesinghe 1997. We recognize that measuring forest light environments with hemispheric photography implies high spatial correlation if the images are separated by only a few meters.…”

“…Individual plants must cope with spatial variation of many resources, including light, and such functionally important heterogeneity is expected to be multidimensional. For instance, access to sunlight is generally negatively correlated with moisture and can shift the balance between the positive and negative effects of microsites or growth areas, with consequent effects on plant performance (Parrish & Bazzaz 1985, Stuefer et al 1994, Stuefer 1996, Hutchings & Wijesinghe 1997, Bugmann 2001.…”

From seedling to sapling: tree species responses to spatial and temporal understory light heterogeneity in disturbed tropical montane forests

“…The ecological interpretation of the light contrasts is focused on the supplement effects (Parish and Bazzaz, 1985;Stuefer et al, 1994;Stuefer, 1996;Hutchings and Wijesinghe, 1997) suggesting that increase survival depends on the habitat context: a C -may have a soothing effect in gaps and hardens conditions within a shade continuum in the understory. On the contrary, a C + may have an intensifying effect in the gap and a balancing one in the understory (Méndez-Dewar et al, 2014).…”

Demographic Consequences of the Two Reproductive Modes in Poa alpina L. along a Primary Succession Gradient in the Central Alps

“…Though there is a large literature on arctic-alpine clonal plants (review in Jó nsdó ttir et al, 1996) and on the benefits of asexual reproduction in experimental settings (Stuefer et al, 1994), cost-benefit analyses either on plantlet or on seed production of P. alpina or other alpine species are lacking. Additionally, any cost-benefit analyses of reproduc- tion modes must also take into account dispersal and establishment processes (Winkler and Fischer, 1999), making any detailed considerations practically impossible.…”