Exhaustive Study Guide: Rangeland Management, Economics, and Ecology

Foundations of Rangeland Economics and Human Welfare

Knowledge and application of rangeland economics principles, approaches, and models allow range managers to achieve multiple objectives, specifically increasing equity, reducing risk, and improving efficiency. Economics is defined as the science of how to produce and distribute goods and services to society. A basic goal of rangeland economics based on maximizing human welfare includes economic growth, equitable distribution of income, and environmental sustainability.

Free trade improves human living conditions by increasing the availability of goods and services. Conversely, price stability refers to managing the economy so that periods of rapidly rising or falling prices for goods and services are minimized or avoided. Globalization is characterized by several key features, including international trade, the integration of financial markets, and the free movement of labor and capital.

Economic Systems and Agricultural Impacts

Centrally planned or command economies (socialistic economies) significantly affect agricultural production and a country’s overall economy. In these systems, the government controls all production and distribution decisions for society with the promise of equitable income distribution and full employment. However, historical evidence indicates that higher-level bureaucrats often enjoy lavish lifestyles while common citizens experience severe poverty. These economies frequently suffer from empty stores, long wait times for basic necessities, low-quality goods, and poor distribution systems. Such structures often reduce efficiency and incentives, leading to lower productivity and potential shortages, ultimately benefiting only a few wealthy individuals or politicians.

Externalities are significant factors in agricultural history. Examples include the severe overgrazing problems on public lands in the late $1800s$, soil erosion from over-farming practices during the Dust Bowl, and the pollution of rivers and air by factories in the $1880s$. In the context of maximizing gross production per land unit, such efforts are merited when real interest rates on borrowed capital are low. Furthermore, the cost and availability of energy influence production; for instance, low oil prices make it financially effective to raise cattle using high inputs of harvested forage and feed grains.

The "Green Revolution" and Modern Agriculture

The "Green Revolution" refers to mid-$20th$-century farming techniques designed to produce enough food for a rapidly increasing global population. This movement depends heavily on high inputs of fossil fuels for irrigation, cultivation, fertilization, harvesting, and transport. While there is pressure to reduce fossil fuel usage, the mass production nature of modern farms means that a reduction could lead to hunger, particularly among the poor, unless the majority of the population returns to producing their own food.

Climate Change and Environmental Stressors

Global warming is primarily caused by $CO_2$ emissions resulting from human fossil fuel usage. Global warming has various adverse impacts on agriculture, such as causing intense droughts followed by intense flooding. It may also increase forage and food production in certain contexts but generally makes regional temperature and precipitation regimes more variable.

Drought is a critical factor in range management, as it can reduce forage production by more than $50\%$ compared to the annual average. Successful ranching depends on a sound knowledge of range management, animal husbandry, and financial management to navigate these environmental fluctuations.

Rangeland Management Operations and Planning

The Bureau of Land Management (BLM) budget includes various projects that serve as examples of integrated resource planning. These include road improvement, water development, controlled burns, fences for rotational grazing systems, and range seeding projects. Public range management goals typically emphasize generating public benefits, such as increasing aesthetic value, rather than prioritizing livestock forage or reducing wildlife habitats. Modern range management also utilizes Geographic Information Systems (GIS) to characterize fluctuations in grassland vegetation productivity.

When site conditions permit, drill seeding is considered the superior method of planting seed over broadcasting or transplanting. The invasion of noxious plants is caused by several factors, including overgrazing by domestic livestock, local landscape fragmentation and denudation due to rapid increases in human populations, and seed transport by grazing or small animals. Mechanical control methods like disking or chaining may be necessary for dense stands where burning or chemicals are unfeasible, though they cause slight soil disturbance and are often less effective against shrubs that sprout below the ground surface. Plants are most sensitive to foliar herbicide sprays when they are growing vigorously and their leaves are fully expanded.

Prescribed Burning and Successional Change

Prescribed burning is a critical tool for manipulating rangelands, but it must be applied with specific conditions. Three elements are necessary for combustion: oxygen, fuel, and heat. Heat is the element that can be manipulated by selecting specific weather conditions for the burn. Before combustion, the fuel must be raised to the appropriate temperature and all moisture must be removed. Sufficient fuel (litter) must be present on a range unit to carry a ground fire.

Unplanned winter burning can have drastic effects on rangeland ecosystems. In northeastern New Mexico, a winter burn changed a shortgrass (blue grama) community into a midgrass plant community consisting of little bluestem and sideoats grama within two years. This transition is marked by an ecotone, or a sharp change in vegetation along the burn line. While burning can lead to water repellency in soil, influencing infiltration, well-planned prescribed burns or patch burning can benefit wildlife by maintaining a variety of vegetation and creating habitat structural diversity.

Livestock Production and Animal Husbandry

Livestock production is significantly impacted by the quality and quantity of water. Cattle and horses require water daily, whereas sheep and goats need water approximately every $2$ to $3$ days. High salt content in forage or water increases water intake. For example, sheep grazing saltbush may require water $2$ times per day. Although sheep and goats have a higher tolerance for salt than cattle, cattle subjected to high total dissolved solids in water will also increase their drinking frequency.

Factors affecting animal selection for rangelands include:

• Topography
• Climate
• Type of vegetation
• Water requirements
• Presence of predators
• Pests and diseases
• Economic and social considerations

Animals such as goats and sheep are best suited for sloping, rocky terrain. In animal husbandry, utilizing a $65$-day breeding season offers advantages such as increased weaning weights, more uniform calf crops, and the ability to identify low-producing cows. Conversely, factors contributing to a reduced calf or lamb crop include predation on young shortly after birth and inadequate nutrition.

Livestock Health and Toxic Plants

Nitrate accumulation in plants poses a severe threat to livestock. Nitrates found in specific weeds disrupt the blood's ability to carry oxygen, leading to death by asphyxiation. Plants known to accumulate nitrates include:

• Crops/Forages: Oat hay, alfalfa, barley, wheat, sorghum, corn, sudangrass, Johnsongrass, and sugar beets.
• Weeds: Carelessweed, kochia, pigweed, Russian thistle, nightshade, bull thistle, Canadian thistle, sunflower, bindweed, and lambs-quarter.
• Vegetables: Lettuce, cabbage, and potatoes.

Wildlife Concerns and Habitat Dynamics

There is increasing concern for wildlife on US rangelands due to a higher human population with greater affluency, which has increased the demand for recreation. Additionally, society is increasingly interested in how food production impacts the environment. Wildlife populations are regulated by the quality and quantity of available habitat. Properly planned brush control can increase the capacity of rangeland to support both livestock and wildlife.

Habitat heterogeneity refers to the existence of two or more different types of habitat in an area. High heterogeneity is exemplified by a pasture with varied grass heights and litter layers (some areas grazed hard, others avoided). Low heterogeneity occurs when grass height and litter are uniform across the area. The "edge effect" occurs where two habitats come together; higher levels of edge effect generally support higher wildlife populations because many species, like mule deer, require diverse vegetation types over short distances to meet their needs.

Interactions Between Livestock, Wildlife, and Small Mammals

Small mammals have both positive and negative impacts on rangelands. Positive impacts include speeding up soil development, enhancing mineral cycling, and contributing to the formation of organic matter. However, species like jackrabbits and prairie dogs are often viewed negatively by ranchers (especially in Nebraska surveys) because they are perceived to compete with livestock for forage. Misperceptions suggest they destroy all forage, but they can actually increase habitat diversity and improve soil conditions.

To reduce competition between big game and livestock, managers can monitor the use of key plant species, identify alternative food sources for wild herbivores, and ensure the range contains key species for both. Indirect effects of livestock grazing on wildlife include the removal or trampling of vegetation used for food or the reduction of plant species diversity. Furthermore, the overkill of predators may lead to explosive populations of big-game rabbits and rodent species.

Law and International Pastoralism

In arid and semiarid regions, individuals who derive the majority of their income and sustenance from livestock grazing are known as "pastoralists." Strategies for pastoralists during drought include reducing livestock numbers. In Africa, communal grazing has sometimes resulted in the destruction of rangeland due to excessive livestock numbers. In the United States, the Wild Free Roaming Horse and Burro Act of $1971$ protects wild horses and burros specifically on public lands.