Seperating the role of biotic interactions and climate in determining adaptive response of plants to climate change
Tomiolo, S. ; Putten, W.H. van der; Tielbörger, K. - \ 2015
Ecology 96 (2015)5. - ISSN 0012-9658 - p. 1298 - 1308.
local adaptation - environmental gradients - positive interactions - species interactions - soil feedback - ecological responses - aridity gradient - global change - evolutionary - communities
Altered rainfall regimes will greatly affect the response of plant species to climate change. However, little is known about how direct effects of changing precipitation on plant performance may depend on other abiotic factors and biotic interactions. We used reciprocal transplants between climatically very different sites with simultaneous manipulation of soil, plant population origin, and neighbor conditions to evaluate local adaptation and possible adaptive response of four Eastern Mediterranean annual plant species to climate change. The effect of site on plant performance was negligible, but soil origin had a strong effect on fecundity, most likely due to differential water retaining ability. Competition by neighbors strongly reduced fitness. We separated the effects of the abiotic and biotic soil properties on plant performance by repeating the field experiment in a greenhouse under homogenous environmental conditions and including a soil biota manipulation treatment. As in the field, plant performance differed among soil origins and neighbor treatments. Moreover, we found plant species-specific responses to soil biota that may be best explained by the differential sensitivity to negative and positive soil biota effects. Overall, under the conditions of our experiment with two contrasting sites, biotic interactions had a strong effect on plant fitness that interacted with and eventually overrode climate. Because climate and biotic interactions covary, reciprocal transplants and climate gradient studies should consider soil biotic interactions and abiotic conditions when evaluating climate change effects on plant performance.
Disentangling above- and belowground neighbor effects on the growth, chemistry and arthropod community on a focal plant
Kos, M. ; Bukovinszky, T. ; Mulder, P.P.J. ; Bezemer, T.M. - \ 2015
Ecology 96 (2015)1. - ISSN 0012-9658 - p. 164 - 175.
soil feedback - associational susceptibility - vegetational diversity - competition - herbivores - root - resistance - responses - fertilization - density
Neighboring plants can influence arthropods on a focal plant and this can result in associational resistance or associational susceptibility. These effects can be mediated by above- and belowground interactions between the neighbor and focal plant, but determining the relative contribution of the above- and belowground effects remains an open challenge. We performed a common garden experiment with a design that enabled us to disentangle the above- and belowground effects of five different plant species on the growth and chemistry of the focal plant ragwort (Jacobaea vulgaris), and the arthropod community associated to this plant. Aboveground effects of different neighboring plant species were more important for the growth and quality of J. vulgaris and for the arthropod abundance on this plant than belowground effects of neighbors. This remained true when only indirect neighbor effects (via affecting the biomass or quality of the focal plant) were considered. The aboveground neighbor effects on arthropod abundance on the focal plant were strongly negative. However, the magnitude of the effect depended on the identity of the neighboring species, and herbivore abundance on the focal plant was higher when surrounded by conspecific than by heterospecific plants. We also observed interactions between above- and belowground neighbor effects, indicating that these effects may be non-additive. We conclude that above- and belowground associational effects are not equally strong, and that neighbor effects on plant-arthropod interactions occur predominantly aboveground.
A multitrophic perspective on functioning and evolution of facilitation in plant communities
Putten, W.H. van der - \ 2009
Journal of Ecology 97 (2009)6. - ISSN 0022-0477 - p. 1131 - 1138.
ammophila-arenaria - soil feedback - sand dune - ecological communities - rhizosphere bacteria - mycorrhizal fungi - insect herbivory - local adaptation - natural enemies - succession
1. Plant facilitation has been studied mostly in the context of plant–plant interactions, whereas multitrophic interactions including those that occur below ground have not yet received much attention. Here, I will discuss how above-ground and below-ground natural enemies and their predators influence plant facilitation and its evolution. 2. Specific above-ground and below-ground plant enemies and their predators play a major role in structuring the composition and dynamics of plant communities. In successional sequences, above-ground and below-ground multitrophic level interactions may tip the balance from competitive to facilitative states and vice versa. 3. Little is known about how above-ground and below-ground multitrophic interactions develop along resource or stress gradients and how the outcomes of above-ground–below-ground interactions depend on variations in these environmental conditions. 4. Facilitated plants need to fit into the above-ground–below-ground multitrophic communities of their facilitators. 5. Little is known also about the evolution of plant facilitation. The observed distance in phylogeny between facilitators and facilitated plants suggests that host-specific enemies may very well co-determine which species become facilitated by which facilitators. 6. Further, very little attention has been given to how plant strategies (allelopathy, accumulation of enemies, monopolization of symbionts) may be the result of selection against being facilitative. 7. Synthesis. Plant facilitation cannot be understood without considering a plant's natural enemies and also its enemies' enemies. Plant enemies can turn competitive interactions into facilitative interactions, whereas the enemies' enemies can turn facilitation back into competition. Below-ground interactions will have longer-lasting effects on facilitation than those above ground, because many organisms can persist in the soil, even when the host plants have disappeared
Is plant biodiversity driven by decomposition processes? An emerging new theory on plant diversity
Mazzoleni, S. ; Bonanomi, G. ; Giannino, F. ; Rietkerk, M. ; Dekker, S.C. ; Zucconi, F. - \ 2007
Community Ecology 8 (2007)1. - ISSN 1585-8553 - p. 103 - 109.
old-field succession - seedling growth - soil feedback - population-dynamics - species richness - tropical forest - ecological significance - germination inhibition - litter decomposition - spatial-patterns
Diversity of forest trees ranges from monospecific stands to the astonishing richness of tierra firma tropical forests. Such patterns are observed along gradients of latitude, altitude, soil fertility and rainfall. So far, the proposed coexisting mechanisms do not provide a comprehensive and unequivocal explanation of these patterns at the community level. We propose a new theory linking species diversity with organic matter cycle and negative plant-soil feedback induced by litter autotoxicity. This approach focuses on resource-waste rather than resource-only dynamics. High diversity does occur where litter decomposition is rapid and ecosystem nutrient cycles are closed. On the other hand, single species dominance is found where litter decomposition is slow and/or autotoxicity is removed from the nutrient cycle pathway. Unlike previous theoretical views, the one we present proves potentially capable of explaining differences in species diversity both along environmental gradients and within the tropics.