(Photograph = Grazing Cattle, Anthony Citrano)

Introduction

Disturbance of habitat can be caused by several factors such as livestock raising, human activities, and land degradation. Disturbance often negatively affects cactus growth and health.

The Details

There are several ways livestock grazing can disturb cacti and cactus-growing areas:

• Animal droppings
• Mechanical damage (by stepping on plants)
• Browsing
• Formation of animal trails
• Soil compaction
• Induction of soil erosion

Interestingly, one study of a Mammillaria species growing in Mexico found that limited animal grazing actually benefited cacti; the cacti showed increased plant density in grazed areas. The particular cactus species in question does not need nurse plants and grows on stony soils. It was hypothesized that limited grazing actually increased areas suitable for growing cacti by removing competing shrubs and grasses.

Additional Reading: Chronic Disturbance Effects on Mammillaria pectinifera