Holistic Resource Management (part 4) The arguments against HRM are interesting. They don't attack the general philosophy, it is the implementation and science behind it that. Here are some arguments taken from: http://trojan.neta.com/~jburgess/hrm.html Savory states that livestock grazing can be managed to stimulate vegetation and improve the water and mineral cycles. While this is true in some areas, it is water that dominates the desert ecology and needs to be considered first. Ecologists mostly agree that natural disturbances of riparian area is preferred to unnatural disturbances such as intensive grazing. Some quotes from Jim Burgess: Many of the West's riparian area's, for instance, have suffered from the tendency of livestock to congregate in them (Chaney 1990). Furthermore, cattle grazing on the uplands surrounding the riparian areas has degraded their watersheds thereby increasing the frequency and intensity of floods (Reynolds 1911). These increased levels of disturbance have led to widespread riparian degradation across the West. Ecosystems can also be damaged when natural disturbances are removed or dampened. Suppression of wildfires by humans has reduced fire frequency, thereby increasing the possibility of hotter, really catastrophic fires. The longer time periods between fires has also led to the invasion of grasslands by fire-susceptible woody vegetation, which isn't as good at slowing erosion and tends to hog water and crowd out many species (Humphrey 1949; Humphrey 1953; Humphrey 1958; Burkhardt 1976; Wright 1976; Young 1981). Another reason for the reduction in range fires is that livestock grazing has, in some places, removed the vegetation needed to fuel them. Savory claims disturbances caused by livestock grazing are natural because vegetation co-evolved with herds of wild grazing animals. But that's not true for the arid rangelands of the Intermountain West. Big herds of large grazing animals, such as bison, haven't been found west of the Rockies since at least the end of the Pleistocene era, more than 10,000 years ago. This is true of many areas where HRM is applied. Savory also argues in favor of livestock-caused disturbances by claiming it's good when cattle trample the vegetation because it helps to speed up the decay of standing organic matter thereby improving the nutrient cycle. But this does little to improve the productivity of the West's arid lands. That's because much of the litter quickly dries out, becomes lighter, and is blown away by wind erosion. Another thing Savory claims is that livestock-caused disturbances are preferable to fire because fire creates more bare ground which causes more erosion. Throughout his book, Savory focuses on the percentage of bare ground and space between plants as the prime factor in determining rates of erosion. And it's been understood for a long time that the percentage of vegetative ground cover plays a big part in determining erosion rates (Forsling 1931; Lowdermilk 1930). However, there are other important factors that affect the rate of erosion which Savory seems to ignore. For instance, Savory asserts that the hoof action of cattle further benefits the land by breaking up the surface of the soil, which slows down runoff and provides a good seed bed for new plants. But research has shown the trampling of the ground by livestock actually increases runoff in two ways. First, it compacts the soil's upper layers, which reduces the ground's ability to soak up water thereby increasing runoff and accelerating erosion. Studies have shown that cattle can compact the soil as much as heavy tractors (Lull 1959) and that it can take more than a year for the soil to rebound from this trampling (Stephenson 1987). Secondly, the primary effect of hooves breaking the soil's crust is not to create good seedbeds, but to accelerate erosion by making the surface more easily washed away, especially on arid lands (Weltz 1986; Taylor 1989; Johansen 1993; Trimble 1995). Some soil crusts, the cryptogamic ones, are alive and contribute to the nutrient cycle in addition to slowing erosion. Cryptogamic crusts also provide habitat for plants. Destroying them doesn't allow "useful" plants to grow, but produces more bare soil. (Anderson 1982; Harper 1985; Ladyman 1996) It's not soil crusting that inhibits seed germination on arid lands, it's the availability of moisture. Studies of the effects of cattle hoof action upon seed germination have found the quantity and timing of precipitation is the most important factor affecting seedling survival (Bryant 1989; Winkel 1991). The fact is, many researchers have concluded that Savory's intense, short duration grazing system can significantly accelerate erosion on the West's arid lands, even more than conventional grazing (Pieper 1988; Thurow 1986; Warren 1986; Weltz 1986; Weltz 1989). The economic ramifications of this are enormous considering the hundreds of millions of dollars that have been spent on surface water storage and delivery systems throughout the West. Savory's characterization of cattle grazing as a disturbance comparable to fire is even stranger if you consider they have very different effects upon the land. On the West's arid grasslands, fire controls woody vegetation while grazing promotes it by removing fuel. In the ponderosa pine forests, periodic fires thin out the trees while grazing promotes dense thickets by removing the ground cover that strangles tree seedlings (Rummell 1951; Belsky 1997). ---- snip ---- This report on HRM goes on for another two pages refuting many of Savory's claims. It is enough to convince me that HRM is a good top level philosophy with some questionable assumptions and implementation. Other viewpoints?
