Summary and conclusions
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Special interest groups, notably vegetarians, are blaming domestic livestock, particularly cattle, for world calamities ranging from global warming to poverty, deforestation, water pollution and desertification. While scientists state that these accusations are not based on fact, they are parroted by the news media. The public is being misinformed and it is not surprising that many individuals are supportive of a call for an ecological renaissance eliminating domestic livestock grazing. This document presents the proper view that livestock can be used to arrest and reverse the desertification process and at the same time, enhance improved animal production. It focuses on FAO's Latin America and the Caribbean region, rangelands and ruminant stock.
To eliminate livestock grazing would be the calamity of all ages.
Domestic livestock have supported mankind for centuries and they must continue to do so. They provide people with nutritious food, clothing, comfort, employment, security, stability, energy, fuel, fertilizer and medicines made from inedible by-products. Small quantities of meat and milk added to cereal and root diets can prevent the adverse effects of protein deficiency such as the killer disease kwashiorkor. Animals provide many people with the energy required to produce their food crops and they provide full and/or parttime employment for 81 million people in Latin America and the Caribbean alone.
The basic importance of ruminants to mankind lies in the fact that these animals obtain their nourishment from fibrous forage and agricultural and industrial by-products which people cannot directly consume or utilize. About 50% of the earth's land surface is incapable of producing anything other than fibrous forage and this land would be of little use to mankind without ruminant livestock. Without ruminants, the disposal of millions of tons of waste products created by the food crop processing industries alone would be the straw that broke the camel's back in an already overburdened garbage disposal system.
At least 50% of the Region is either too dry, too wet, too steep, too shallow, too infertile and/or too fragile to sustain cultivation or to support arborescent forests. These are the Region's rangelands which provide ninety or more percent of the food consumed by millions of head of cattle, sheep, goats, alpaca, llama, equines and wildlife. Rangelands are also the Region's watersheds. There are approximately 1,026.5 million hectares of rangelands, and considering that one square meter of land yields one liter of water for each millimeter of rain, and assuming that 15% of this water either runs off or percolates to an aquifer, the amount of water that the rangelands yield is beyond imagination. Rangelands also have wildlife, recreational and aesthetic values.
A fundamental importance of rangelands is the fact that they are a natural renewable resource and their renewability is remarkable. The Region's ranges have been and are being abused and are producing only a fraction of their potential. Fortunately, most have not deteriorated to a stage in which production cannot be improved through natural renewable processes. Unfortunately, rangelands do not receive the attention they deserve by planners, policy makers, livestockmen and bi-lateral and international assistance organizations.
If man intends to live and depend upon these lands on a sustained basis, this abuse must stop. Sustainable use and management must become the rule rather than the exception.
Desertification is the degradation of both the living organisms and non-living environment of an ecosystem caused by man's interventions and abuses. The process is marked by increasing microaridity and erosion and declining productivity. The end product is a desert-like state in which total photosynthesis is of little use to man and beast. This state is called "decertified". Some claim that desertification is caused by a changing macroclimate, but the rapidity in which desertification is occurring in some areas indicates that this is not the case. Such rapid rates of vegetation change would require a climatic change of huge magnitude and one that certainly could be measured by meteorological instruments. However, there is no evidence of this.
If there is a permanent warming trend due to a greenhouse effect, this again is due to man's activities such as the prodigious use of fossil fuels and the excessive use of other products that release gases into the atmosphere. Domestic ruminants do generate methane, but so do ruminant wildlife, coal mines and human and agricultural wastes. Claims that domestic ruminants contribute significantly to global methane production and global warming is highly questionable and yet to be proven scientifically.
Desertification is caused by the cultivation of lands incapable of sustaining agriculture, deforestation, an ever increasing population, fuel gathering, lack of land use policies and continual destructive grazing. Examples of the enormity of these causal factors are given in the text. There is no evidence that deforestation of tropical forests is due to the American hamburger trade. This is attributed to lack of land use policies and populations that are outgrowing land capacity. The fundamental cause of desertification on either arable, forest or rangelands is use beyond their capabilities.
Man has caused and is causing desertification and only man can undo what he has done and is doing.
Technologies which will allow man to better control his environment and to enhance and assure his quality of life are known and new ones are being continually developed. If the professional alarmists and special interest groups are serious, one would think that they would be more interested in supporting the implementation of these technologies, rather than making spectacular and illogical recommendations. It appears that they are either unaware of the technologies or prefer to ignore them. Their constructive contributions could be most helpful and beneficial.
Desertification is a process which can be diagnosed by symptoms or manifestations such as vegetation composition changes, upset water regimes, soil erosion, microclimate changes, increasing microaridity, decreasing productivity, increasingly sparse vegetation and diminution of usefulness. The process has stages which are technically measurable on ranges and probably also on forest and arable lands. There are also rates. It may take hundreds of years of grazing for ranges to reach a decertified and nonrenewable state. The tractor and plough can create a decertified range in just a few years. The ax or bulldozer can cause a decertified tropical forest in days.
To understand desertification on rangelands, its control and reversal, one must have some knowledge of certain plant physiological, ecological and environmental phenomena and principles. An attempt is made to describe and illustrate these in a manner that can be readily understood by the uninformed. Moreover, to understand the role of domestic livestock in desertification control, one must also know that livestock can be manipulated in order to achieve a desired effect for both the animals and environment. Ways and means for achieving this are also described and illustrated, hopefully, in a convincing and understandable manner. These plant physiological, ecological and environmental phenomena, functions and principles are all a part of range management.
Range management is a relatively new discipline defined as: "The science and art of planning and directing rangeland use in order to obtain maximum sustained economic livestock production consistent with the conservation and/or improvement of the related natural resources, soil, water, vegetation, wildlife and recreation. " Range management has two objectives; (1) obtaining maximum sustained economic livestock production and (2) conservation and/or improvement of the related natural resources. Scientific range management stands on the premise that the range resources can be improved and grazed perpetually by domestic stock and, at the same time, produce high-quality watersheds, wildlife, recreation, desertification control and, where suitable, forest products. Research and practical application of range management principles and practices have shown this to be true and as solid as the Rock of Gibraltar.
In order to achieve these objectives, the manager must not only plan and direct rangeland use for maximum forage production, he must also see that the forage is efficiently converted by animals on a sustainable basis into consumable products. Plant husbandry and animal husbandry can never be considered separately in range management. This is illustrated as follows;
Poor Producers + Poor Converters = Very Low Production
Poor Producers + Good Converters = Low Production
Good Producers + Poor Converters = Low Production
Good Producers + Good Converters = Maximum Production.
Unfortunately, range management, all practical purposes, is unknown in the Region.
Plants are living organisms that have nutritional requirements the same as people and livestock. A major and most important difference between plants and animals is in their sources of energy. Plants can use energy supplied by the sun to change inorganic matter taken from the earth and from the air into organic compounds. Animals cannot secure directly from the sun the energy necessary for their life. They must live on the organic energy-rich compounds built by plants. Plants must be properly nourished in order to carry out photosynthesis and to build complex organic compounds and they must provide that nourishment themselves. Their role is twofold: first to feed themselves and second to feed man and his animals. It is imperative that plants be properly fed so that they can successfully carry out both roles. A system of grazing that does not permit plants to properly feed themselves will result in eventual plant death due to starvation, poor animal production and desertification.
It is the range manager's responsibility to plan, direct and manipulate grazing in such a manner that the range forage plants can adequately feed themselves and live to produce forage and to protect the environment. The nutritional status of forage plants depends on defoliation or grazing intensity, frequency and season of use. As a general rule, 50 to 60% defoliation will leave enough leaf area for adequate nutrition of the plant. Thus, the range manager has adopted the slogan "take half - leave half." The technicalities regarding plant utilization are explained in the text. With knowledge of these, grazing can be manipulated to assure healthy and productive forage plants and maximum sustained animal production.
The rangeland ecosystem is a complex phenomenon involving a multitude of interrelated functions with each influencing the others. The system's major components are: producers, converters, soils, decomposers and microconsumers, microclimate and manipulators. Desertification is the degradation of these components. Plants are the producers and their well-being influences the well- being of the other components. Vegetation can be manipulated and be made either more or less efficient in gross energy production depending on the physiological and ecological responses to manipulations. Energy outputs below potential, resulting in declining productivity is a desertification symptom.
Animals are converters and the impact they have on the ecosystem can be significant but controlled. The impact can either improve or impair the overall function of the system. Modern day people are the great manipulators and domestic stock are their principal tool. They can manipulate grazing to either destroy, improve or maintain a rangeland ecosystem, but improvement with subsequent maintenance must be the objective. This can be achieved with the application of range management principles and practices.
The Americas' explorers described an abundance of rich and lush natural pastures. Like a sea of grass, some said, and some described the grasses as being up to their stirrups and higher in places. Tall grass prairies dominated the Pampas. Chile's annual ranges were dominated by perennials. There was no shortage of forage for the indigenous peoples' llamas and alpacas in the Altiplano. The dry and humid tropical savannahs were free of brush and even the arid areas flourished with grasses and shrubs palatable to livestock. These were the Region's "climax" rangelands. They represented the "natural potential" and the highest form of natural development that the environmental factors were capable of producing. Settlers came with their livestock and one of the world's most colorful and largest livestock industries was built. Having no precedents to follow, the industry's builders thought that the bountiful vegetation would regenerate and last forever. It did not, because of an ecological phenomenon called "succession." This is nature's way of replacing one community of plants by another one and there are two kinds: progressive and regressive (retrogression). Retrogression is the replacement of a community of higher ecological order with one of a lower order which can be caused by continual destructive grazing. This is why the bountiful vegetation encountered by the settlers did not regenerate and last forever. Misuse caused retrogression and declining productivity.
There are two kinds of progressive succession: primary and secondary. Primary is the historic development of vegetation and soils which terminated in climax. Secondary is any progressive succession after primary.
Mother Nature is very forgiving. She always tries to restore what man has destroyed. This is the case of secondary succession. A disturbance of climax will cause retrogression, but, if given the opportunity, nature will make every effort to restore the damage via secondary succession. Secondary succession is much faster than primary because the soil is already formed, although deteriorated and needing restoration as well. Secondary succession gives the manipulator a very valuable and useful tool.
The fact that one community of plants can replace another is important for desertification control and livestock production. Range condition is a measure of the stage of succession in relation to climax or natural potential as determined by the proportions of desirable, less desirable and undesirable species. Condition is classified as being either excellent, good, fair or poor. Grazing capacity increases with an increase in range condition. Grazing capacities of good and excellent condition ranges are several times higher than on poor and fair condition ranges. Environmental stability also increases with an increase in range condition. Other features involving range condition and range sites are presented in the text.
Upset water regimes created by reduced infiltration and excess surface runoff and soil erosion are desertification symptoms. These in turn promote increasing microaridity, decreasing productivity and diminution of usefulness. Studies and experiences have shown that infiltration increases and that erosion and runoff decrease with increases in range condition. One study showed, except for highly erodible soils, that stabilization can be attained with low good or high fair condition ranges. Studies have also shown that moderate grazing intensity (proper degree of utilization) can maintain a favourable forage resource without increasing the hazard of erosion. It could produce good quality runoff water for use outside the watershed. Both improved range condition and proper degree of utilization can be achieved with manipulations of livestock. Superior livestock production and desertification control will also be achieved.
The influence of livestock on bacterial contamination of water appears to be minimal in arid and semiarid areas. There is evidence that livestock grazing near mountain streams can contribute to some bacterial contamination, although recreationists contribute as well and probably more.
Many range management practices have been developed since the science was born some fifty years ago and new ones are being developed. These practices are aimed at controlling desertification and at obtaining maximum sustained animal production. While specifics will vary, the application of these practices in principle is badly needed in the Region. Desertification symptoms are widespread and average ruminant production is pitifully low. Of the regions where meat is eaten, only Africa has lower production levels than the Latin American and Caribbean region.
Paramount among these practices is proper stocking. Proper use is a degree of utilization of current year's growth which, if continued, will achieve management objectives and maintain or improve the long-term productivity of the site. Our objectives are to arrest and reverse desertification and to obtain maximum sustained livestock production. Proper stocking is placing a number of animals on a given area that will result in proper use at the end of the planned grazing season. No range management practice will be successful if it is not accompanied with proper stocking.
If one had to select a single factor that affects per animal and per unit land area production the most, that factor would have to be stocking rate as related to degree of forage use. For this reason, a considerable amount of the text is dedicated to this subject.
Meat and milk demand exceeds supply in most countries. There are two ways to increase production and at the same time control desertification: (1) increased grazing capacity and (2) increased individual animal productivity. The former can be achieved with improved range condition and proper stocking will contribute significantly to the latter. The relationship between stocking rates and animal production show that the adage "more livestock - more produce" is not always true. As strange as it might sound, total livestock production in the Region will be greater with less animals than at present and a great step towards desertification control will have been taken. Other practices designed to arrest and reverse the desertification process and to obtain maximum sustained economic livestock production are described in the text.
In conclusion, the grazing animal is a part of the vegetation's environment and the vegetation a part of the animal's. So long as the two live together, the welfare of each is dependent on the other. A grazing method that causes desertification is neither in the interest of the vegetation's welfare nor in the animal's. Domestic livestock grazing is a useful management tool to prevent this. Thus, animals can play a major role in desertification control. It is up to man to see that they do. However, a look into the future is not bright because of the numerous constraints that must be overcome. Some outstanding ones are listed.