attacking coffee and the shade trees Grevillea robustaand Erythrina lithosperma
(Gowda et al. 1995).
Nematodes and Mycorrhizal Fungi in Coffee Ecosystems
Of the many nematode species that attack coffee, the 11 species of Meloidog-
yne,4 species of Pratylenchus, Radopholus similis,and Rotylenchulus reniformis,
and 3 species of Hemicriconemoidesare considered to be of economic impor-
tance; nonpathogenic nematodes found in coffee soils include the genera
Criconemoides, Helicotylenchus, Nothocriconema, Rotylenchus, Scutellonema,and
Xiphinema(Kumar and Samuel 1990).
Vesicular arbuscular mycorrhizae in arabica and robusta coffee roots have
received some research attention because of their impact on phosphorus
uptake. In India, Glomus macrocarpum, Sclerocystis rubiformis, Gigaspora gigan-
tea,and Gigaspora heterogamahave been identified (Rangeshawaran et al.
1990). In Colombia, 20 species of vesicular arbuscular mycorrhizae have been
identified in coffee plantations, including six species of Acaulospora,nine
species of Glomus, Gigasporasp., Scuttellosporasp., Entrophospora colombiana,
and Sclerocystis sinuosa(Bolaños et al. 2000).
Benefits and Costs of High Faunal Diversity in Coffee Ecosystems
Although the presence of a diverse and abundant fauna in shaded coffee plan-
tations is clearly beneficial from a conservation viewpoint, it is not clear what
the benefits or costs are to the farmer who owns and manages the plantation
(but see Gobbi 2000; Bray et al. 2002). Potential benefits include the fulfill-
ment of ecological services such as pollination (Roubik 2002), seed dispersal,
soil regeneration, and pest regulation. Although there are few data on the
potential importance of these ecological services, several studies suggest that
the presence of parasites and predators in shaded coffee plantations could help
control insect pest outbreaks. For example, almost 25 percent of all arthropods
collected and 42 percent of the species found in a species-rich shade planta-
tion near Tapachula, Chiapas, Mexico, were predators and parasites (e.g., spi-
ders, ants). Similarly, 83 percent of the 322 insect species found in Costa
Rican coffee plantations were species with potential as biological control
agents (Gonzalez 1999b). Some of the mammals found in shaded coffee plan-
tations might also control pest populations by feeding on insects or small
rodents (Gallina et al. 1996). From a farmer’s point of view, the drawbacks of
having a rich animal community include the potential for damage to occur to
nearby crops and the potential for harm to domestic animals or humans from
large mammals and snakes. Unfortunately, no studies have considered these
potential impacts (see also Chapter 13, this volume).
- Biodiversity Conservation in Neotropical Coffee Plantations 215