Effects of Eucalyptus Plantations on Detritus, Decomposers, and Detritivores in Streams

• DOI: 10.1100/tsw.2002.193
• Publication Date: 2005-03-23T13:13:39Z
• Authors: Manuel A.S. Graça; Jesus Pozo; Cristina Canhoto; Arturo Elosegi
• Keywords: Decomposer; Plant litter; Litter; Monoculture; Nutrient cycle; Undergrowth; Forest floor

Vast areas of the Iberian Peninsula are covered by monocultures exotic tree Eucalyptus globulus . Given that (1) leaf litter produced in riparian is main energy source for small streams, and (2) trees differ their nutrient content, chemical defenses, physical attributes, eucalypt plantations have potential to affect biology streams. Research teams from University Coimbra Basque Country been addressing effects at several levels study. Here we review conclusions these investigations. Eucalypt less than some deciduous forests. However, there were marked differences timing litterfall: production peaked during autumn forests, whereas forests it tended peak summer be more evenly distributed throughout year. Despite differences, average standing stock organic matter was higher forest. This may attributed occurrence spates or heavy rain autumn, period maximum fall bark accumulation Because composition, input seems lower The rate decomposition leaves strongly dependent on nutrients water: nutrient-poor waters slower most other species, nutrient-rich can as fast alder – a fast-decaying species. biomass cumulative diversity aquatic hyphomycetes colonizing did not between native but fungal sporulation generally 2 weeks later leaves. lag disappeared when lipids (but polyphenolics) chemically removed Similarly, addition oils culture media retarded suppressed growth. Streams bordered had spores similar spore densities) Portugal; consistent patterns found experiments Spain. proved poor food shredders. Under laboratory conditions ranked low selection using same shredders failed grow died fed exclusively removal resulted increased feeding rates, transfer decreased rates. effect stream invertebrate communities very consistent. In waters, fewer invertebrates colonized leaves, this mitigated after microbial conditioning waters. Portuguese streams numbers surrounded Spanish nonexistent looking composition communities, which change year site site. Most studied Portugal Spain dried up summer, fact might reflect an increase soil hydrophobity plantations. short planting-to-harvest results additional impacts, such loss, siltation reduced amounts woody debris channels, affects capacity retain leaf-litter, well availability habitat fish. studies research confirm importance maintaining buffer strips reduce human impact rivers.