The first abiotic factor would be temperature, Tropical Grasslands have a very warm temperature year round. Precipitation would be the next abiotic factor, the Savanna receives up to about 60 inches a year. The third abiotic factor would be humidity, the humidity is very high in the Tropical Grasslands. The final factor would be topography which is elevation and land features. Some areas in the Savanna have higher elevation and some are lower.