NOTES WEEK 9 Sofia Cornejo León
SOIL PROCESSES
Changes in communities may be
CHANGES IN COMMUNITIES IN RESPONSE TO POLLUTION
Structural changes relate to composition.
Functional approach, measure the operation of the carbon or nitrogen and determine whether it is adversely affected by pollutants
There are advantages in combining approaches
Carbon and nitrogen cycle operate in soils, and provide indices of the function of soil communities. Stages: CO2 production and nitrification, can be measured
CYCLES
Under normal environmental conditions, these cycles are subject to the influence of environmental factors
Method of estimating hazards of chemicals to microorganisms
Microoranisms have important role in the cycles
involves determination of the rate formation in soil samples
the testing of pesticides, Herbicides, fungicides, insecticides, may be expected to have effects on soil organisms and fertility
Marine systems
Soil
Fresh waters
River invertebrates’ prediction and classification scheme (RIVPACS), Belgian index for rivers
A variety of indices can be used to assess the health of sediments affected by pollution (taxonomic distinctiveness index, uses nematodes)
Similar examples are much harder to come by, a reason for is the lack of identification keys for some of the most speciose groups
‘Before and after’ studies are rare in ecotoxicology
The sea empress, a tanker which spilled 70 000 ton of crude oil into Milford haven, Wales, in feb 1996.
Normally, % cover of the rocks with seaweed is low because of the grazing activities of limpets (Patella vulgata), after the spill limpet mortalities were high, resulted in a dramatic phase of seaweed Enteromorpha, followed by a flush of Porphyria, and last a brown phase of Fucus
BUT, we have soil prediction and classification scheme (SOILPACS).
Methods which have been used to assess the impact of aerial deposition of metals on soil are leaf litter communities
Oligochaetes are particularly susceptible to the pollution
ZMG pollution problem: In rainy season, the acid rain will go from ZMG to La Primavera, because of the direction of the wind (to the west, where is the forest). In dry season, the problem is forest fires, one reason is the organic matter accumulation due to low degradation rate. the use of calcium carbonate (lime), may be a solution.