DOI: 10.5061/dryad.fc07k
title: Data from: Consumer control as a common driver of coastal vegetation worldwide

description: Rapid, global anthropogenic alteration of food webs in ecosystems
 necessitates a better understanding of how consumers regulate natural
 communities. We provide a global synthesis of consumer control of
 vegetation in coastal wetlands, where the domineering role of physical
 factors such as nutrient and salinity, rather than consumers, has been
 emphasized for decades. Using a dataset of 1748 measures of consumer
 effects reported in 443 experiments/observations on all continents except
 the Antarctica, we examine the generality of consumer control in salt
 marshes and mangroves globally. Our analyses show that salt marsh
 herbivores, including insects, snails, crabs, waterfowl, small mammals,
 and livestock, generally and often strongly suppress plant survival,
 aboveground biomass, and height, while their effects on plant density,
 belowground biomass, reproduction, and cover are more variable. These
 effects occur in forbs, grasses, and shrubs, and in both seedlings and
 adult plants. Herbivores additionally affect plant nutrient stoichiometry,
 and mediate plant interactions, though their effects on plant diversity
 are less consistent. Higher trophic levels also affect plants, as
 predators facilitate plant growth through trophic cascades that suppress
 grazer abundance and grazing rate. In mangroves, there are also signs of
 consumer control, though the relatively few studies available have often
 focused on mangrove propagules and seedlings rather than adults. Our
 analyses further reveal that the strength of consumer control is regulated
 by many physical factors. Nutrient, disturbance, and flooding, for
 example, amplify the negative effects of herbivores. Along latitudinal
 gradients, increased temperature enhances the negative effects of
 ectothermic herbivores, but has no effect on those of endothermic
 herbivores. Consumer control of coastal plants is also apparent across
 study methodologies: in field and laboratory settings, in observational
 studies, in consumer exclusion and addition experiments, in natural and
 transplanted plants, and in experiments of various durations. The role of
 consumer control in coastal vegetation worldwide highlights the need to
 better recognize and theoretically conceptualize both top-down and
 bottom-up forcing and their interactions in coastal wetlands. Improved
 understanding and conservation of coastal wetlands will only occur if we
 incorporate what the science has revealed: trophic feedbacks are an
 important and pervasive determinant of coastal plant communities.
description: Dataset 1 Coastal
 wetland consumer effect synthesis AllThis dataset contains
 the data from all consumer effect studies included in the
 analysisDataset 2 Coastal
 wetland consumer effect synthesis Competition subsetThis dataset contains
 data collected from studies that examined the effects of consumers on
 plant competitionDataset 3 Coastal
 wetland consumer effect synthesis Environmental factor
 subsetThis dataset contains
 data collected from studies that crossed consumer treatments with
 environmental factors