Range Plants

Learning to recognize range plants and their role in the ecosystem is key to good range management.

Range plants can be grouped based on various characteristics including plant type, season of growth, origin, response to grazing and forage value².

Plant Type

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The management of rangelands is based on the following basic principles and practices:

• balance livestock demand with forage supply – balancing grazing animal needs with available forage supply is often referred to as ‘proper use’. Determining the amount of forage to graze while leaving adequate carryover is generally set at 40-50% but may be more or less, depending on growing conditions, the type of plants, and stage of growth. 
• distribute grazing pressure across the landscape – management of grazing distribution is important to prevent areas of over- or under-utilization. Many factors influence animal grazing patterns (topography, vegetation type, forage palatability, quality and quantity, location of water, salt, mineral, shade and shelter, fences, pasture size, stock density).
• provide effective rest periods after grazing to allow plants to recover – rest is key to prevent overgrazing. The length of time that a plant needs to recover depends on the type of forage, plant vigour, level of utilization, season of grazing, soil type/range site, and environmental conditions.
• manage grazing livestock most suited to the forage supply and management objectives – proper selection and management of grazing animals as a forage-harvesting tool allows range managers to meet the basic principles of range management including balancing demand and supply, livestock distribution, and rest and recovery. Estimating forage requirements for each type and class of livestock includes using animal unit equivalents (AUE) to calculate stocking rates.

Application of these four principles will support healthy productive rangelands. Forage can be grazed to sustain livestock while leaving adequate ungrazed residue (plant litter) behind to sustain rangeland ecosystem function. Strategic fencing, water development and salt placement can help promote more even livestock distribution. Being aware of plant growth patterns will allow for timing of grazing to avoid defoliation when plants are most sensitive to grazing pressure and for implementation of rest periods.

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Grazing during the optimal growth period (which will vary with each forage species) and when growing conditions are favourable, will allow for high rates of photosynthesis and regrowth IF plant material remains after grazing. A general rule of thumb often used as a guideline by grazing managers is a level of utilization of 50%. This generally indicates a moderate level of grazing intensity.

The timing of grazing is less important than making sure that plants are given enough time to rest and recover after grazing. Regrowth takes time and a grazing plan needs to include removing animals from a pasture to ensure that plants are not regrazed before having a chance to recover. Planned grazing systems, such as rotational grazing, employ this knowledge to control grazing animal impacts.

Visit the Grazing Management topic page for a more in-depth overview of grazing principles and practices.

Rangeland Health

“Range health” describes the ability of rangeland to perform certain key functions¹. In a healthy rangeland the integrity of the soil, vegetation, water and air, as well as the ecological processes of the rangeland ecosystem, are balanced and sustained⁵. All parts of the ecosystem are present and working together. Healthy rangelands:

• produce forage for livestock and wildlife
• maintain and protect soil from erosion
• capture and release water
• cycle nutrients and energy, and
• maintain biological diversity.

 

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The original concept of range condition was developed in response to the deterioration of western rangelands caused by grazing mismanagement and included development of published stocking rate guides (Alberta in 1966⁶ and extended to Saskatchewan in 1990⁷). Range condition describes the current state of vegetation compared with that of the potential for the site (known as the climax plant community) and was used to measure either deterioration or improvement. Four classes of range condition (Excellent, Good, Fair, Poor) explain how the composition of the present plant community has changed from that of the climax community.

The range condition approach worked well in semi-arid rangelands and was accepted by land managers; however, a number of shortcomings were identified. One of the key assumptions was that any decline in range condition was reversible and experience showed that that is not always the case. For example, when communities are invaded by non-native species, they may not show a trend back towards to the climax plant community no matter the management treatment applied. Also, the traditional range condition concept does not consider requirements for soil protection or grazing management impacts on soil.

Evaluating range health improves upon the original range condition approach by adding indicators, particularly for soil and site conditions, which producers can observe and are easier to measure than plant community alone. Rangeland health assessment tools have been developed to measure how well management principles and practices are being achieved (see example below). These assessments better address problems like irreversible changes in range condition and invasion of non-native species. Range health determines the ability of rangeland to produce forage, protect the soil, and efficiently cycle water and nutrients in a state of biological diversity.

The following video defines rangelands (0:50), covers the basic principles of range management (1:35), highlights an assessment tool (3:49), and outlines steps in a rangeland assessment (4:33).

Assessing rangeland health starts by examining the existing plant community for desirability, diversity and density. Grazing severity, soil erosion, litter residue (dead plant material), disturbance and invasive species/noxious weeds are also taken into account in determining range health.

The next video shows a rangeland health assessment conducted on three sites in southern Alberta with varying degrees of grazing pressure. It defines the five key functions of rangelands (1:39) and compares lightly (3:23), heavily (9:55), and very heavily (12:51) grazed pastures.

Range managers use rangeland health assessments to ensure that grazing management practices are not damaging the soil, water or range resource and that management decisions are producing the expected results. Healthy range scores indicate good overall grazing management, but range assessments may still identify specific areas where changes can be made. Declines in range health scores alert managers to consider management changes, especially in those areas that score lower in the assessment.

A sample Grassland Range Health Assessment worksheet¹ is shown below illustrating the evaluation of range health indicators and the steps taken to arrive at a range health score (Healthy = 75-100%; Healthy with Problems = 50-74%; Unhealthy < 50%).

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Where to Find Assessment Tools?

Rangeland health assessment tools and resources are available in many provinces by contacting regional or provincial forage, grazing or cattle associations, extension specialists, or agrologists.

Riparian Management and Assessment

A riparian zone⁸ is the area adjacent to streams, rivers, lakes, and wetlands, where the vegetation and soils are strongly influenced by the presence of water.

Healthy riparian areas trap and store sediment, build and maintain streambanks, store flood water, recharge groundwater, act as a filter and buffer to maintain water quality, reduce and dissipate stream energy to slow erosion, maintain biodiversity, provide wildlife habitat, and produce forage.

Unhealthy riparian areas are characterized by weeds, reduced forage production, damaged shrub growth, down cutting and erosion of the channel, slumping banks, soil exposure, low water table and decreased storage capacity with few fish or wildlife present.

The following video defines riparian zones (1:01), outlines the benefits of these areas (1:31), and describes assessment of the health of riparian zones (3:01).

Riparian areas are extremely productive components of a grazing program and with proper management cattle, grass and waterways can coexist in a long-term sustainable ecosystem. However, because riparian areas are also important areas for protecting water quality, they are very sensitive to uncontrolled grazing. If access isn’t controlled, cattle will concentrate in a riparian area because of water, salt, shade, or forage availability. Early and mid-summer use can be detrimental to riparian areas unless grazing is limited in duration and frequency so that plants can recover.

Video courtesy of: Southern Alberta Land Trust Society and Cows and Fish

Grazing can work well when grazing duration is managed to minimize browsing, rubbing and trampling of shrubs and small trees. Fall and winter grazing can be successful when forage is sufficient for grazing through the snow, when enough residue is left to slow the water flow from next spring's runoff, when supplemental feeding sites are far enough away from the riparian area, and cattle are discouraged from resting there. Avoid bale grazing near riparian areas to ensure that nutrient runoff does not flow directly into waterways.

The use of remote or off-stream watering sites can reduce the impacts of livestock in riparian areas with benefits including improved water quality and increased animal performance. In order to attract cattle away from riparian areas to make use of off-stream watering systems, management strategies should consider a grazing plan that ensures adequate forage in upland areas, as well as alternative options for shade and protection from the heat.   

The following video outlines strategies, including placement of fences (1:37), to improve and maintain riparian health plus discusses many of the positive outcomes (3:25) that result from good riparian management.