A unified meta-ecosystem dynamics model: Integrating herbivore-plant subwebs with the intermittent upwelling hypothesis

Determining the relative influence of biotic and abiotic processes in structuring communities at local to large spatial scales is best understood using a biogeographic comparative-experimental approach. Using this approach, previous work suggests that intertidal community dynamics (top-down and bottom-up effects) vary unimodally along an upwelling-based productivity gradient, termed the Intermittent Upwelling Hypothesis (IUH). Evidence consistent with the IUH comes from the sessile invertebrate/predator (SIP) subweb in certain rocky intertidal communities, but whether this pattern extends to macrophyte/herbivore (MH) subwebs is unknown. Here we ask: Are MH subwebs also structured as predicted by the IUH? What is the relative importance of herbivory and predation in structuring these communities? Under what conditions do ecological subsidies like nutrients or propagule production drive community dynamics? And are omnivorous interactions important? We hypothesize that MH subwebs are drive..., Study Systems
Research was done on wave-exposed rocky benches on the OR and northern CA coast located in the California Current Large Marine Ecosystem (LME), and NZ, located in the New Zealand Shelf Large Marine Ecosystem (Fig. 2). Experiments were done in OR and NZ, and supplementary data on nutrients and macrophyte cover were obtained in CA by the PISCO consortium. Tidal ranges were 3.0 to 3.5 m in OR and CA and 2.1 (east coast) to 3.4 m (west coast) in NZ (Appendix S1: Table S1). OR/CA experiences mixed semi-diurnal tides (i.e., successive low or high tides are of unequal height, with one “good” low tide per day during spring tide periods), while NZ tides are semi-diurnal (daily low and high tides are of similar height). Except for Nine-Mile Beach in NZ, sites used in this study have lengthy histories of continuous ecological research, beginning in 1983 in OR, the 1990s in CA, and 1994 in NZ.
Environment
Experiments in NZ and OR were conducted between October 2004 to October 2007 and..., Excel or similar spreadsheet.