DOI: 10.5061/dryad.mv13v
title: Data from: Early plant recruitment stages set the template for the development of vegetation patterns along a hydrological gradient

description: 1. Recruitment processes are critical components of a plant's life
 cycle. However, in comparison with later stages in the plant life cycle
 (e.g. competition among adults), relatively little is known about their
 contribution to the regulation of plant species distribution. Particularly
 little is known about the individual contributions of the three main
 recruitment processes—germination, seedling survival, and seedling
 growth—to community assembly, while quantitative information on these
 contributions is essential for a more mechanistic understanding of the
 regulation of plant species distribution and biodiversity. 2. Riparian
 zones along streams provide a globally-relevant case study for evaluating
 the importance of the different stages of plant recruitment. The natural
 hydrological gradients of stream riparian zones are currently being
 restored after a period of worldwide habitat degradation. To identify how
 recruitment contributes to vegetation patterns and biodiversity in
 riparian zones, we carried out field experiments at restored lowland
 streams. We quantified the germination of introduced seeds, and survival
 and growth of introduced seedlings of 17 riparian plant species across a
 gradient from the stream channel to upland. 3. The hydrological gradient
 of riparian zones acted as a strong environmental filter on all three
 recruitment processes, through imposing an abiotic limitation (excess
 water) at low elevations and a resource limitation (water shortage) at
 higher elevations. Other variables, such as soil organic matter content
 and nutrient availability, only affected recruitment marginally. 4.
 Species-specific patterns of environmental filtering initiated niche
 segregation along the riparian gradient during all three recruitment
 processes, but particularly during germination and seedling growth. These
 recruitment niches appeared strongly related to indicator values for adult
 distribution optima, suggesting that at least some riparian plant species
 may have evolutionary adaptations that promote recruitment under
 favourable hydrological conditions for adult growth and reproduction. 5.
 Our results suggest that strong environmental filtering during germination
 and seedling growth plays an important role in determining later adult
 distributions, by forming the spatial template on which all subsequent
 processes operate. In addition to well-known mechanisms, such as
 competitive exclusion at the adult stage, environmental filtering during
 early recruitment stages already strongly affect plant distribution and
 diversity.
description: Fraaije et al. field
 experimentsEight worksheets with
 data on experimentally studied recruitment processes (germination,
 seedling survival, and seedling growth: worksheet 1-3), re-structured for
 multivariate analyses (worksheet 4-6), soil parameters (worksheet 7) and
 description of column headers (worksheet 8).Fraaije et al. mesh bags
 control experimentTwo worksheets
 containing data on a control experiment which tested the effect of mesh
 bags on germination, with the data in worksheet 1, and description of
 column headers in worksheet 2.