Effects of Land Use Change and Seasonality of Precipitation on Soil Nitrogen in a Dry Tropical Forest Area in the Western Llanos of Venezuela

Table 2

Seasonal changes in the available soil ammonium in the forest and pastures.

Season	Depth  (cm)	Available ammonium (N-N), g m^−2
		Forest	YP	OP
End rainy season	0–5	3.3 ± 1.7^Aa	2.8 ± 1.1^Aa	5.6 ± 0.9^Ab
Dry season	0–5	2.7 ± 1.0^Aa	1.0 ± 0.3^Bb	1.2 ± 0.3^Bb
Early rainy season	0–5	0.7 ± 0.2^Ba	0.6 ± 0.1^Ba	0.7 ± 0.2^Ba

Mean values ± standard deviation. Different lower case letters indicate significant differences between sites (). Different capital letters indicate significant differences between seasons (). YP: 5-year-old pasture; OP: 18-year-old pasture.