Dataset Information

Ontogenetic variation in salinity tolerance and ecophysiology of coastal dune plants.

ABSTRACT:

Background and aims

Global climate change includes shifts in temperature and precipitation, increases in the frequency and intensity of extreme weather events and sea level rise, which will drastically impact coastal ecosystems. The aim of this study is to quantify salinity tolerance and to identify physiological mechanisms underlying tolerance across wholeplant ontogeny in two widespread native coastal plant species in Hawai'i, Jacquemontia sandwicensis (Convolvulaceae) and Sida fallax (Malvaceae).

Methods

At the seed, seedling, juvenile and mature ontogenetic stages, plants were exposed to high salinity watering treatments. Tolerance was assayed as the performance of stressed compared with control plants using multiple fitness metrics, including germination, survival, growth and reproduction. Potential physiological mechanisms underlying salinity tolerance were measured at each ontogenetic stage, including: photosynthesis and stomatal conductance rates, leaf thickness, leaf mass per area and biomass allocation.

Key results

Salinity tolerance varied between species and across ontogeny but, overall, salinity tolerance increased across ontogeny. For both species, salinity exposure delayed flowering. Physiological and morphological leaf traits shifted across plant ontogeny and were highly plastic in response to salinity. Traits enhancing performance under high salinity varied across ontogeny and between species. For J. sandwicensis, water use efficiency enhanced growth for juvenile plants exposed to high salinity, while chlorophyll content positively influenced plant growth under salinity in the mature stage. For S. fallax, transpiration enhanced plant growth only under low salinity early in ontogeny; high transpiration constrained growth under high salinity across all ontogenetic stages.

Conclusions

That salinity effects vary across ontogenetic stages indicates that demographic consequences of sea level rise and coastal flooding will influence population dynamics in complex ways. Furthermore, even coastal dune plants presumably adapted to tolerate salinity demonstrate reduced ecophysiological performance, growth and reproduction under increased salinity, highlighting the conservation importance of experimental work to better project climate change effects on plants.

SUBMITTER: Lum TD

PROVIDER: S-EPMC7442332 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

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Publications

Ontogenetic variation in salinity tolerance and ecophysiology of coastal dune plants.

Lum Tiffany D TD Barton Kasey E KE

Annals of botany 20200201 2

<h4>Background and aims</h4>Global climate change includes shifts in temperature and precipitation, increases in the frequency and intensity of extreme weather events and sea level rise, which will drastically impact coastal ecosystems. The aim of this study is to quantify salinity tolerance and to identify physiological mechanisms underlying tolerance across wholeplant ontogeny in two widespread native coastal plant species in Hawai'i, Jacquemontia sandwicensis (Convolvulaceae) and Sida fallax ...[more]

PMID: 31162531

Similar Datasets

Project description:Coastal dune plants are subjected to natural multiple stresses and vulnerable to global change. Some changes associated with global change could interact in their effects on vegetation. As vegetation plays a fundamental role in building and stabilizing dune systems, effective coastal habitat management requires a better understanding of the combined effects of such changes on plant populations. A manipulative experiment was conducted along a Mediterranean dune system to examine the individual and combined effects of increased sediment accretion (burial) and nitrogen enrichment associated with predicted global change on the performance of young clones of Sporobolus virginicus, a widespread dune stabilizing species. Increased burial severity resulted in the production of taller but thinner shoots, while nutrient enrichment stimulated rhizome production. Nutrient enrichment increased total plant biomass up to moderate burial levels (50% of plant height), but it had not effect at the highest burial level (100% of plant height). The effects of such factors on total biomass, shoot biomass and branching were influenced by spatial variation in natural factors at the scale of hundreds of metres. These results indicate that the effects of burial and nutrient enrichment on plant performance were not independent. Their combined effects may not be predicted by knowing the individual effects, at least under the study conditions. Under global change scenarios, increased nutrient input could alleviate nutrient stress in S. virginicus, enhancing clonal expansion and productivity, but this benefit could be offset by increased sand accretion levels equal or exceeding 100% of plant height. Depletion of stored reserves for emerging from sand could increase plant vulnerability to other stresses in the long-term. The results emphasize the need to incorporate statistical designs for detecting non-independent effects of multiple changes and adequate spatial replication in future works to anticipate the impact of global change on dune ecosystem functioning.

Dataset Information

Ontogenetic variation in salinity tolerance and ecophysiology of coastal dune plants.

Background and aims

Methods

Key results

Conclusions

Publications

Ontogenetic variation in salinity tolerance and ecophysiology of coastal dune plants.

Similar Datasets

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