Permanent vegetation plots to understand the temporal dynamics of plant communities
LOTVS (LOng-Term Vegetation Sampling) is a collection of temporal vegetation data recorded using permanent plots worldwide. At present, it includes vegetation time-series from 79 datasets, for a total of ~8000 plots and ~4500 plant species recorded. Permanent plots in LOTVS were sampled for at least 6 years (with a range of 6 to 53 years, mostly with yearly records) in grasslands, shrublands and forest understory around the globe (see the map below or click here for an enhanced and interactive version of the map). An overview of the data included in the LOTVS collection is available on Zenodo.
Permanent-plot studies are considered among the most important developments in vegetation science over the past 30 years. Relying on sampling units with a fixed location and a consistent sampling approach, permanent plots allow for a regular detection of vegetation changes in time. This delivers robust time-series of species abundances within ecological communities, essential data for answering ecological questions about the stability of species and ecosystems, including their resistance and resilience to on-going climate and land-use changes.
The stability of ecological communities is critical for the stable provisioning of ecosystem services such as food and forage production, carbon sequestration and soil fertility. Ecosystems are subject to temporal variations in environmental conditions including various stressors and disturbance events. Several studies have reported alarming changes in species populations in response to global change drivers, with the decline of some species and the increase of others. An important aspect of the functioning of ecosystems is their temporal stability, which includes their response to both extrinsic (environmental conditions) and intrinsic (community changes) factors. By using permanent plots in natural conditions it is thus possible to evaluate components of ecological stability and test the robustness of long-term trends in species and ecological functions (Figure 1). Compared to other important approaches, such as vegetation resurveys (resampling of plots often performed at irregular time intervals, not always using the same exact location), permanent plots offer a unique opportunity to unravel the complex patterns and mechanisms of species and community variation in time.
Figure 1. Schematic representation of the type of permanent plot temporal data and their importance for assessing the stability of species and communities: note how yearly sampledpermanent plots allow tracking resistance and recovery to extreme events, while depicting the fluctuations around overall trends (from de Bello et al. 2020).
As Bakker et al. (1996) well summarized, maintaining permanent plots is not an easy task: “it needs a great deal of discipline to maintain a series of permanent plots and analyse them yearly over a period long enough to answer relevant (ecological) questions”. The LOTVS initiative is a collaborative research platform that aims at: 1) making the data collected so patiently by researchers around the globe more visible and comparable, and 2) assessing relevant ecological questions across a number of taxa, ecosystems and regions.
All plant ecologists collecting permanent plot data are welcome to contribute to LOTVS if they are willing to collaborate on common studies or ask for the data elaborated within the project. The membership to the LOTVS platform is therefore fully open to all ecologists, particularly committed to maintain permanent plots and share part of their collected data. New participants are included regularly. Contact us in case you would be interested in contributing to this database and resulting publications. The data policy allows contributors to retain the ownership of their data, which is not made public. The data can be made available, on request, based on flexible agreements and on sound scientific proposals. Contributors are clearly offered co-authorship if their data is used for data analyses and consequent publications.
The assembly of the LOTVS database into the present form was made possible by two funding bodies: originally from The Czech Science Foundation (GACR 16-15012S, running between 2015 and 2018) and, at present, by the Spanish State Research Agency (Plan Nacional de I+D+i, project PGC2018-099027-BI00, from 2019 to all 2022) which supports this page. Clearly, to collect their data all contributors have benefited from a wide variety of research funds to maintain the sampling in their permanent plots. These institutions are acknowledged in the original publications that already exist from their data (the key ones listed here).
