L-545510/06Texas Rangeland Monitoring:Level ThreeC. Wayne Hanselka, Charles R. Hart and Allan McGinty*Monitoring is an essential tool in rangeland management. Monitoring is the way to determine whether goals are being achieved with current management strategies. A sound rangeland monitor-ing program identifies trends and helps the manager make better decisions in managing natural resourc-es. It also confirms good management practices while revealing potential problems early.The Texas Rangeland Monitoring Program is a rapid, simple and inexpensive way to monitor vegetation structure and the ecological processes of semi-arid rangelands. Level one monitors changes in plant communi-ties and soils using permanent photo points (see Extension publication L-5216, “Range Monitoring with Photo Points”). Level two monitoring adds more detail related to rangeland health by docu-menting and tracking changes in the herbaceous and woody plant communities (see Extension publication L-5454, “Texas Rangeland Monitoring: Level Two”). Level three monitoring adds additional indicators related to ecological processes important to rangeland health.Rangeland healthRangeland health is the degree to which the integrity of the soil, vegetation, water, air and ecological processes are balanced and sustained. Ecological processes are those that enable an ecosys-tem to function as it should to retain soil, capture and store water, and support a viable biotic commu-nity. These processes are nutrient cycling, energy flow, water cycling, and vegetation dynamics.*Extension range specialists, The Texas A&M University System.Level three monitoring uses a quantitative scor-ing system that ranges from 1 (nonfunctional) to 5 (fully functional as would be expected in an unal-tered reference area). Each variable in the landscape pattern and the four ecological processes is scored, and then the scores are averaged to obtain a func-tional score for each process.Landscape terrain and patternLandscape patterns affect ecological function. Water and nutrients are redistributed and captured by numerous “patches” and “sinks” such as grass clumps, brush thickets, depressions, etcetera. Thus, the functioning of the rangeland is strongly influ-enced by terrain (shape and slope) and patchiness of vegetation (numbers, size and spacing). Losses can occur from fire and grazing.To score the landscape pattern, first establish a line transect as described in Extension publication L-5216. Survey the shape of the terrain along the line to locate topographic features such as depres-sions and flats, and vegetation patches such as large grass plants, grass clumps, shrubs, brush thickets, etcetera. (Fig. 1). There are three indicators that are estimated or measured:1. Number of patches per unit area. This is an estimate of the number of patches, by patch type, on the site. Count the number of patches that intersect the line transect and note what kinds of patches they are. Then document the number of patches per unit of space, such as the number per 10 feet or the number per square foot. Rate them from few (1) to many (5). Few (1) = no patches per 10 feet Many (5) = ten patches per 10 feet2. Patch size. This is the area of each patch that is intercepted by the transect. Estimate the length and width of each patch and calculate its area. Rate patches small (1) or large (2). Small (1) = 1 square foot Large (5) = > 25 square feet3. Distance between patches. The third indica-tor is the distance between patches. The clos-er together the vegetation patches, the less water is lost from evaporation or runoff from bare soil. Estimate or measure the distancebetween patches along the transect and calculate the average distance. Rate them from far apart (1) to close together (5). Far apart (1) = 100 feet between patches Close together (5) = 1 foot between patchesEcological processesNutrient cycling. Minerals and nutrients cycle through the ecological system and may be 1) removed from the soil by plants and returned to the soil as plants decay, or 2) consumed by animals and returned to the system through animal waste or decomposing bodies. Nutrients are temporarily lost to the system through livestock grazing and by being tied up in plant materials that are slow to decompose. The rate of litter breakdown is the most important indicator of mineral and nutrient cycling. In a healthy system nutrients are returned quickly. In an unhealthy system dead leaves stay on grasses and oxidize rather than decaying, and dry manure and dung pats remain intact without being broken down by insects and other decomposers. Rate litter breakdown from slow (1) to rapid (5).Energy flow. Plants capture solar energy and convert it to carbohydrates used by the plants and/or transferred to other parts of the ecosystem. The abundance of broad-leaved plants and the closeness of plant spacing are measures of energy flow; this is measured by the extent of the live plant canopy over the transect. Note the total area of leaf and the health of plants. Rate the live canopy of plants from poor (1) to abundant (5). Poor (1) = 0 percent Abundant (5) = > 75 percent Water cycling. While the amount and timing of rainfall are important, the productivity of rangeland is more closely tied to the amount of soil moisture captured when it rains and the presence of desirable plant species to use that moisture. Current and past management practices determine how much rainfall penetrates the soil, the kinds of plants on the land, and the amount of runoff, sediment and non-point source pollutants that leave the property. Factors that affect how much rainfall penetrates the soil, runs off or evaporates include the type and density of vegetative cover, the intensi-ty of rain, the amount of moisture in the soil before the rain, the capacity of the soil to hold water, and the slope of the land.Figure 1. Number, size, and the distance between patches affect the functioning of ecological processes.Figure 2. Compacted or capped soil inhibits aeration, water infiltration and seedling establishment.Figure 3. Erosion removes soil from the base of plants, leaving them on a “pedestal.”Figure 4. A wide diversity of plant species indicates an advanced plant community.There are three indicators of the functioning of the water cycle.• Soil capping. Hard, capped soil and compac-tion layers indicate a problem with water infiltration, aeration and seed germination (Fig. 2).