This may occur in all soil types including dense soils. Natural arsenic levels in groundwater and soils vary. Spills also take out crops and aquacultures through contamination of groundwater and soils. It prefers moist or wet, nutrient rich, muddy soils. Malvasia tends to prefer dry climates with vineyards planted on sloping terrain of well-drained soils. Aluminium is primary among the factors that reduce plant growth on acidic soils. Plants and animals grown in iodine deficient soils are correspondingly deficient. Settlements developed on the new silt soils deposited near the coast. Loess tends to develop into highly rich soils. Most grow best in wet environments and moist soils. Chaparral is predominant in areas characterized by thin, rocky soils and little moisture. This can be an advantage in excessively leached tropical rain forest soils. It survives in wet sandy and peaty soils. These occurrences are in line with the prevailing acidic character of most oak forest soils. The peat produces black soils, which are directly comparable to the American muck soils.