Reliability of presence-only data for assessing plant community
responses to climate warming
Abstract
Climate warming has triggered shifts in plant distributions, resulting
in changes within communities, characterized by an increase in
warm-demanding species and a decrease in cold-adapted species - referred
to as thermophilization. Researchers conventionally rely on
co-occurrence data from vegetation assemblages to examine these
community dynamics. Despite the increasing availability of presence-only
data in recent decades, their potential has largely remained unexplored
due to concerns about their reliability. Our study aimed to determine
whether climate-induced changes in community dynamics, as inferred from
presence-only data from the Global Biodiversity Information Facility
(GBIF), corresponded with those derived from co-occurrence plot data in
Norway. To assess the differences between these datasets, we quantified
a Community Temperature Index (CTI) from the co-occurrence data set and
compared this with CTI obtained from presence-only data. We also
examined the temporal trend in CTI (i.e., thermophilization) in both
datasets. To do this, we first established a species-temperature
relationship based on data before climate warming. In a preliminary
analysis, we assessed the performance of this relationship using three
datasets: 1) Norwegian co-occurrence data, 2) presence-only data from a
broader European region organized into pseudo-plots (potentially
capturing more species niches), and 3) a combined dataset merging 1) and
2). The transfer function including both datasets performed best.
Subsequently, we compared the CTI for the co-occurrence plots paired up
spatially and temporally with presence-only pseudo-plots. The results
demonstrated that presence-only data can effectively evaluate species
assemblage responses to climate warming, with consistent CTI and
thermophilization values in comparison to co-occurrence data. Employing
presence-only data for evaluating community responses opens up better
spatial and temporal resolution and much more detailed analyses of such
responses, our results therefore outline how a large amount of
presence-only data can be used to enhance our understanding of community
dynamics in a warmer world.