Search for: All records

Abstract AimEvaluate the temporal changes in species diversity, composition, and structure of ephemeral plant communities and the seed bank in response to long‐term herbivore exclusion over 11 years in plots with and without herbivores. LocationNorth‐central Chile. MethodsWe obtained information on ephemeral vegetation cover in August and September using the intercept point method and recorded seed abundance in April. The Bosque Fray Jorge National Park Long‐Term Socio‐Ecological Research (LTSER) provided these records covering 11 years (2009–2019). From the original experiment of 20 plots, we used eight plots divided into two treatments: four plots allowed free access to all herbivores (with herbivores), while the other four plots excluded herbivores (without herbivores). ResultsWe found that Hill–Shannon diversity increased in plant communities with herbivores and a temporal increase in the cover of the dominant species,Plantago hispidula, under herbivore exclusion. In wet years, species richness and temporal turnover of plant communities increased independently of treatment. Although seed abundance differed among treatments and years, population structure remained constant over time and among treatments, suggesting that the seed bank acts as a buffer against shocks that modify plant community dynamics. Structural equation modeling revealed that precipitation, via its positive effects onPlantago hispidula, increases native plant richness to a greater extent than herbivores. However, in the absence of herbivores, precipitation directly affects native species richness. Moreover, we found that precipitation also influences the native species richness of the seed bank, both directly and indirectly, although its impacts exhibit a time lag. ConclusionsOur study demonstrates that the temporal dynamics of ephemeral plant communities and seed banks in semi‐arid ecosystems are strongly coupled to climate variability, highlighting the vulnerability of these communities to biodiversity loss and climate change. 

ABSTRACT MotivationHere, we make available a second version of the BioTIME database, which compiles records of abundance estimates for species in sample events of ecological assemblages through time. The updated version expands version 1.0 of the database by doubling the number of studies and includes substantial additional curation to the taxonomic accuracy of the records, as well as the metadata. Moreover, we now provide an R package (BioTIMEr) to facilitate use of the database. Main Types of Variables IncludedThe database is composed of one main data table containing the abundance records and 11 metadata tables. The data are organised in a hierarchy of scales where 11,989,233 records are nested in 1,603,067 sample events, from 553,253 sampling locations, which are nested in 708 studies. A study is defined as a sampling methodology applied to an assemblage for a minimum of 2 years. Spatial Location and GrainSampling locations in BioTIME are distributed across the planet, including marine, terrestrial and freshwater realms. Spatial grain size and extent vary across studies depending on sampling methodology. We recommend gridding of sampling locations into areas of consistent size. Time Period and GrainThe earliest time series in BioTIME start in 1874, and the most recent records are from 2023. Temporal grain and duration vary across studies. We recommend doing sample‐level rarefaction to ensure consistent sampling effort through time before calculating any diversity metric. Major Taxa and Level of MeasurementThe database includes any eukaryotic taxa, with a combined total of 56,400 taxa. Software Formatcsv and. SQL.