7/29/2011. Vegetation Sampling and Wildlife Management Techniques. Lesson Overview. Introduction. Preliminary preparation

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1 Vegetation Sampling and Wildlife Management Techniques Dr. Nova Silvy Regent s Professor Department of Wildlife & Fisheries Sciences Texas A&M University 1 Lesson Overview Preliminary preparation Vegetation sampling techniques Applications 2 Introduction Why sample? - Evaluate vegetation response to management - Estimate carrying-capacity capacity - Characterize cover and habitat components for endangered species - Long-term monitoring of general trend of plant vigor or habitat condition. 3 1

2 Initial steps to sampling vegetation Development of specific objectives. General aspects of vegetation: - Species composition - Spatial distribution, either vertical or horizontal - Temporal variation in structure -Biomass - Overall stand or landscape structure 4 Initial steps to sampling vegetation Example goal is to inventory natural nesting cavities for wood ducks, requires number of natural cavity trees near water. Action buffer riparian zones, sample older trees. 5 Preparations and getting started Initial planning and preparation - Data forms - Preliminary field test - Training i of field crew 6 2

3 Importance of Preparatory Work Try your proposed methods BEFORE beginning actual data collection. - What works what doesn t - Efficiency - Practicality - Test data forms 7 7 Sample Number Depends on many variables Best procedure - Obtain initial field sample - Analyze data Statistically determine sample number for level of accuracy required Species area curve 8 Sample Number Determine min. # of sample--using initial sample and statistics Species area curve # of Species # of Sample size 9 3

4 Vegetation Inventory and Analysis Density Dominance Frequency 10 Density Answers question how many. Expressed per some commonly used unit area 11 Density Absolute or actual density - Number of individuals per unit area - Total absolute (all species) - Absolute of specific species Relative density - Specific species - Expressed as % 12 4

5 Dominance Measure size, bulk, or weight Answers question how much. 13 Dominance Characteristics Measured - Weight or biomass Best Difficult & time consuming - Basal cover or basal area Area of ground surface covered by bases of plants - Canopy cover (foliar or crown cover) or canopy area - Area of ground covered by vertical projection of canopy to ground surface 14 Dominance Expression of basal area or canopy cover - Absolute or actual Total absolute dominance (all species) Absolute dominance of a species Dominance/unit area (2,500 m2/hectare) - Relative to ground surface covered All species Specific species % 15 5

6 Frequency Measures Commonness and Distribution Answers Question Where species located and how common Expressed as - % of sample plots in which species occurs - Only determined by species - Frequency of specific species relative to all species: poorly defined quantity 16 Vegetation Measurements Frequency percentage of sample units in which a species occurs. Describes the distribution of plants. 17 SAMPLING METHODS Plot or Area - Quadrat - Transect Plotless - Point Quadrat (area quadrat reduced to a point) - Line Intercept (transect reduced to a line) - Distance (e.g., Point-Centered-Quarter) 18 6

7 Quadrat Methods Requires 3 characteristics to be considered: - Plant distribution, - Size and shape - Number of samples 19 Quadrat methods Plot size varies with different forms of vegetation. Rectangular plots have advantages over square and circular plots in aggregated communities. 20 Plotless Methods Do not use boundaries, based on premise that density may be estimated from the mean distance/area between 2 plants. Nearest-neighbor, random-pairs, and point-centeredquarter (PCQ). 21 7

8 Cover Vertical projection of the crown or stem of a plant onto the ground surface. - Quadrat-charting method - Ocular estimates - Line intercept - Point intercept - Densiometer 22 Cover Variable radius method (prism method) 23 Biomass One of the best indicators of species composition is based on dry weight. - Clipping techniques - Direct estimations - Dimension analyses 24 8

9 Sampling fruits Mast traps Seed traps or counting directly with binoculars. 25 Other Attributes Visual obstruction important to wildlife because serves as hiding and thermal cover. - Wight density board - Nudds vegetation profile board - Robel range pole 26 Other Attributes Plant height Tree trunk dimensions Tree age Plant use 27 9

10 END OF LESSON 28 10