Sergey Rosbakh1, Shyam S Phartyal1,2, Peter Poschlod1. 1. University of Regensburg, Ecology and Conservation Biology, Institute of Plant Sciences, Regensburg, Germany. 2. H. N. B. Garhwal University, Department of Forestry and NR, Srinagar-Garhwal, India.
Abstract
BACKGROUND AND AIMS: Hydroperiod drives plant community composition in wetlands, resulting in distinct zonation patterns. Here, we explored the role of seed germination traits in shaping wetland community assembly along a hydroperiod gradient. Specifically, we tested the hypothesis that seeds of reed, mudflat, swamp, shallow- and deep-water communities only germinate under a specific set of environmental factors characterized by the community-specific optimal conditions for seedling survival and growth. METHODS: In a three-factorial experiment, we tested the seed germination response of 50 species typical for temperate wetlands of Europe to temperature fluctuations (constant vs. fluctuating temperature), illumination (light vs. darkness) and oxygen availability (aerobic vs. hypoxia). Phylogenetic principal component analysis, cluster analysis and phylogenetic linear regressions were used to confirm the community-specific seed germination niches. KEY RESULTS: Our study revealed the presence of five distinct, community-specific seed germination niches that reflect adaptations made by the study communities to decreasing light intensity, temperature fluctuations and oxygen availability along the hydroperiod gradient. Light as a germination trigger was found to be important in mudflats, swamps and shallow water, whereas the seeds of reed and deep-water species were able to germinate in darkness. A fluctuating temperature is only required for seed germination in mudflat species. Germination of species in the communities at the higher end of the hydroperiod gradient (reed and mudflat) demonstrated a strict requirement for oxygen, whereas swamp, shallow- and deep-water species also germinated under hypoxia. CONCLUSIONS: Our study supports the recent argument that the inclusion of seed germination traits in community ecology adds significant insights to community response to the abiotic and biotic environment. Furthermore, the close relationship between seed germination adaptations and community assembly could help reach a better understanding of the existing patterns of wetland plant distribution at local scales and wetland vegetation dynamics, as well as facilitate nature conservation measures and aquatic habitat restoration.
BACKGROUND AND AIMS: Hydroperiod drives plant community composition in wetlands, resulting in distinct zonation patterns. Here, we explored the role of seed germination traits in shaping wetland community assembly along a hydroperiod gradient. Specifically, we tested the hypothesis that seeds of reed, mudflat, swamp, shallow- and deep-water communities only germinate under a specific set of environmental factors characterized by the community-specific optimal conditions for seedling survival and growth. METHODS: In a three-factorial experiment, we tested the seed germination response of 50 species typical for temperate wetlands of Europe to temperature fluctuations (constant vs. fluctuating temperature), illumination (light vs. darkness) and oxygen availability (aerobic vs. hypoxia). Phylogenetic principal component analysis, cluster analysis and phylogenetic linear regressions were used to confirm the community-specific seed germination niches. KEY RESULTS: Our study revealed the presence of five distinct, community-specific seed germination niches that reflect adaptations made by the study communities to decreasing light intensity, temperature fluctuations and oxygen availability along the hydroperiod gradient. Light as a germination trigger was found to be important in mudflats, swamps and shallow water, whereas the seeds of reed and deep-water species were able to germinate in darkness. A fluctuating temperature is only required for seed germination in mudflat species. Germination of species in the communities at the higher end of the hydroperiod gradient (reed and mudflat) demonstrated a strict requirement for oxygen, whereas swamp, shallow- and deep-water species also germinated under hypoxia. CONCLUSIONS: Our study supports the recent argument that the inclusion of seed germination traits in community ecology adds significant insights to community response to the abiotic and biotic environment. Furthermore, the close relationship between seed germination adaptations and community assembly could help reach a better understanding of the existing patterns of wetland plant distribution at local scales and wetland vegetation dynamics, as well as facilitate nature conservation measures and aquatic habitat restoration.
Authors: Arne Saatkamp; Anne Cochrane; Lucy Commander; Lydia K Guja; Borja Jimenez-Alfaro; Julie Larson; Adrienne Nicotra; Peter Poschlod; Fernando A O Silveira; Adam T Cross; Emma L Dalziell; John Dickie; Todd E Erickson; Alessandra Fidelis; Anne Fuchs; Peter J Golos; Michael Hope; Wolfgang Lewandrowski; David J Merritt; Ben P Miller; Russell G Miller; Catherine A Offord; Mark K J Ooi; Annisa Satyanti; Karen D Sommerville; Ryan Tangney; Sean Tomlinson; Shane Turner; Jeffrey L Walck Journal: New Phytol Date: 2018-10-25 Impact factor: 10.151
Authors: Morgane B Gillard; Jesús M Castillo; Mohsen B Mesgaran; Caryn J Futrell; Brenda J Grewell Journal: Am J Bot Date: 2022-07-09 Impact factor: 3.325