Early plant recruitment stages set the template for the development of vegetation patterns along a hydrological gradient

By Rob G. A. Fraaije, C. T. ter Braak, Betty Verduyn, Leonieke B. S. Breeman, Jos T. A. Verhoeven, M. Soons. 2015

104 citations recorded by the source corpus.

Summary 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. 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 world-wide 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. 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. 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. 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.

Subfields: Ecology, Nature and Landscape Conservation

View Paper: https://www.semanticscholar.org/paper/109f7a3c86eeccbf3338ebb0545128c343a186b6

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology

1. A. Brochet
2. Erik Kleyheeg
3. A. Green
4. M. Soons
5. J. Larson
6. J. Funk
7. J. Peig
8. Ran Nathan

In Nature and Landscape Conservation

1. A. Brochet
2. Erik Kleyheeg
3. M. Soons
4. A. Green
5. J. Larson
6. J. Funk
7. J. Peig
8. Ran Nathan

Citations in the corpus

• Seed dispersal by dabbling ducks: an overlooked dispersal pathway for a broad spectrum of plant species (2016, background): “Furthermore, non-germinating seeds may still be viable (Brochet et al. 2010b), but dormant, as germination rates are highly sensitive to environmental conditions (e.g. Fraaije et al. 2015b).”
• Regeneration: an overlooked aspect of trait‐based plant community assembly models (2016, background): “…processes on plant populations and communities, greater incorporation of regeneration traits into trait–filter assembly models could provide new insight into patterns of community composition and species distributions (e.g. Ozinga et al. 2004; Fraaije et al. 2015; Rosbakh & Poschlod 2015).”
• Twenty years of P-splines (2015, methodology): “Basically INLA uses a parameter for each observation so a (B-spline) regression basis has to be implemented in an indirect way, as a matrix of constraints (Fraaije et al., 2015).”