Plant trait and vegetation data along a 1314 m elevation gradient with fire history in Puna grasslands, Perú.

Alpine grassland vegetation supports globally important biodiversity and ecosystems that are increasingly threatened by climate warming and other environmental changes. Trait-based approaches can support understanding of vegetation responses to global change drivers and consequences for ecosystem functioning. In six sites along a 1314 m elevational gradient in Puna grasslands in the Peruvian Andes, we collected datasets on vascular plant composition, plant functional traits, biomass, ecosystem fluxes, and climate data over three years. The data were collected in the wet and dry season and from plots with different fire histories. We selected traits associated with plant resource use, growth, and life history strategies (leaf area, leaf dry/wet mass, leaf thickness, specific leaf area, leaf dry matter content, leaf C, N, P content, C and N isotopes). The trait dataset contains 3,665 plant records from 145 taxa, 54,036 trait measurements (increasing the trait data coverage of the regional flora by 420%) covering 14 traits and 121 plant taxa (ca. 40% of which have no previous publicly available trait data) across 33 families.

Germination and seedling growth of Calluna vulgaris is sensitive to regional climate, heathland succession, and drought.

The coastal heathlands of Northwest Europe are highly valued cultural landscapes, that are critically endangered due to land use and climatic changes, such as increased frequency and severity of drought events. Our study is the first to assess how the germination and early seedling growth of Calluna vulgaris respond to drought. In a factorial design field experiment, we exposed maternal plants to three in-situ drought treatments (control, 60%, 90% roof coverage), across three successional stages after fire (pioneer, building, mature), and two regions (60°N, 65°N). Seeds from 540 plants within the experiment were, weighed, and exposed to five water potentials, ranging from -0.25 to -1.7 MPa, in a growth chamber experiment. We recorded germination (percentage, rate), seedling growth (above- vs. belowground allocation), and seedling functional traits (specific leaf area [SLA], specific root length [SRL]). Overall variation in germination between regions, successional stages, and maternal drought treatments was largely mediated by variation in seed mass. Plants from the northernmost region had higher seed mass and germination percentages. This is indicative of higher investment in seeds, likely linked to the populations' absence of vegetative root sprouting. Seeds from the mature successional stage germinated to lower final percentages than those from earlier successional stages, especially when the maternal plants had been exposed to drought (60% and 90% roof coverage). Exposure to reduced water availability decreased germination percentage and increased the time to 50% germination. Seedlings fully developed in the range -0.25 to -0.7 MPa, with increased root:shoot and lower SRL during reduced water availability, suggesting a resource-conservative response to drought during the early stages of development. Our results thus suggest a sensitivity to drought during the germination and seedling life-history stages that may reduce Calluna's ability to re-establish from seeds as the incidence and severity of droughts are projected to increase under future climates.

Registered Reports: A new chapter at Ecology & Evolution.

Ecology & Evolution has published its first Registered Report and offers the perspective of the editor, author, and student on the publication process.