Genetic variation within a dominant shrub structures green and brown community assemblages.

Two rising challenges in ecology are understanding the linkages between above- and belowground components of terrestrial ecosystems and connecting genes to their ecological consequences. Here, we blend these emerging perspectives using a long-term common-garden experiment in a coastal dune ecosystem, whose dominant shrub species, Baccharis pilularis, exists as erect or prostrate architectural morphotypes. We explored variation in green (foliage-based) and brown (detritus-based) community assemblages, local ecosystem processes, and understory microclimate between the two morphs.

Radish introduction affects soil biota and has a positive impact on the growth of a native plant.

Introduced plants may out-compete natives by belowground allelopathic effects on soil communities including the symbionts of native plants. We tested for an allelopathic effect of an introduced crucifer, Raphanus sativus, on a common neighboring legume, Lupinus nanus, on the legume's rhizobium affiliates, and on the broader soil community. In both field observations and a greenhouse experiment, we found that R.

Facilitation and predation structure a grassland detrital food web: the responses of soil nematodes to isopod processing of litter.

1. Detritus can support successive consumers, whose interactions may be structured by changes in the condition of their shared resource. One model of such species interactions is a processing chain, in which consumers feeding on the resource in a less processed state change the resource condition for subsequent consumers.

What can we learn from resource pulses?

An increasing number of studies in a wide range of natural systems have investigated how pulses of resource availability influence ecological processes at individual, population, and community levels. Taken together, these studies suggest that some common processes may underlie pulsed resource dynamics in a wide diversity of systems. Developing a common framework of terms and concepts for the study of resource pulses may facilitate greater synthesis among these apparently disparate systems.

Response of nematode-trapping fungi to organic substrates in a coastal grassland soil.

To understand why Arthrobotrys oligospora and other nematode-trapping fungi are common and sometimes abundant in the coastal grassland soils of the Bodega Marine Reserve (BMR, Sonoma County, CA), we examined how resident trapping fungi responded to the addition of eight organic substrates (lupine leaves, grass leaves, dead isopods, dead moth larvae, isopod faeces, deer faeces, shrimp shells, and powdered chitin). We were especially interested in the effects of dead isopods because isopods are abundant at BMR and because previous studies had documented strong responses of A. oligospora to other arthropods (dead moth larvae).

A basal aquatic-terrestrial trophic link in rivers: algal subsidies via shore-dwelling grasshoppers.

Rivers provide important resources for riparian consumers, especially in arid or seasonally arid biomes. Pygmy grasshoppers (Paratettix aztecus and P. mexicanus; Tetrigidae) graze river algae stranded along shorelines of the South Fork Eel River in northern California (39°44'N, 123°39'W) as the river recedes during the summer drought.