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20 Cards in this Set
- Front
- Back
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Edge Effect |
1. Increase in density of populations of edge species where 2 habitat types meet (not more diversity) 2. Access to 2 habitat types > variety of vegetation |
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Edge |
Edge is the boundary where 2 habitat types meet |
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Edge formula |
D = a+kS Animal density (D) is proportional to length of edge (s) (a) is animal density in the absence of edge (k) is proportionality constant |
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edge - how is it produced/considerations |
1. Edge can be produced by the removal of woody plants - brush, trees, grassland mgmt, agriculture, forest clearings 2. Considerations for brush control: Method, Pattern, Size |
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Roller-chopping, shredding, disking, chaining |
- nonselective, broad scale - promotes resprouting - retreatment (2-5yrs) |
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root-plowing |
nonselective, broad scale eliminates all woody plants decreases diversity |
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bulldozing, hydroaxe, mulching, grubbing, shears |
individual, selective bulldozing and & grubbing eliminate all woody |
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Diversity of woody species (mechanical brush control) |
1. Elimination of woody species not desired 2. community composition is a concern 3. initially diversity not affected, more treatments → diversity decreases 4. root plowing dramatically decreases diversity |
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Herbaceous Cover (mechanical brush control) |
1. Increased herbaceous cover after treatment 2. temporary with roller chopping, shredding, disking. 3. root plowing may require reseeding 4. increased forb and grass production |
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Forage production (mechanical brush control) |
For cattle, WTD (forbs) Birds (seeds) Resprouting shrubs - increased nutritional value for browsers |
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Clearing pattern & size |
regular = cheaper, animals may be less likely to utilize clearcut irregular = more expensive, more natural distances > species will travel from cover will not be utilized r = max distance from cover |
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Fragmentation |
consequence of too much edge with respect to contiguous blocks of critical habitat |
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advantages of herbicides (4): |
1. little soil disturbance 2. stems and trunks of defoliated plants provide cover and shade for wldlfe 3. selective suppression of woody species 4. reduced competition for establishment of desirable grasses/forbs |
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disadvantages of herbicides(5): |
1. many broad leaved herb. plants are forage for spp. 2. foliar sprays restricted to certain stages of development 3. restricted application of foliar sprays (wind and temp.) 4. resistant species increase 5. residues |
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Residues |
That quantity of herbicide remaining in or on the soil, or plant parts contamination issue residue must persist for a time to be effective soil applied forms last longer |
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Herbicide application methods (2) |
Aerial application - fixed wing, helicopter
Ground application tractor mounted hand application back pack, foliar, basal, handwicking soil applied |
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Modes of action (herbicides) |
foliar-active - translocated Contact herbicides - rapid action soil-active herbicides - root or shoot inhibitors |
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Management use (herbicides) (6) |
1. personal preference 2. Species specific herbicides & application rates-3. Create and maintain openings 4. manage composition of herbaceous 5. enhance wildlife food plants 6. in conjunction with mechanical methods, manage wildlife w/o degradation |
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Creative use (herbicides) |
- removal of brush/brush canopy - Tebuthiuron(Graslan) elminates whitebrush, leaves mesquite savannah. standing dead material provides screening, no damage to forb or grass - Picloram (Tordon) - damages forb production/food availability soil-active herbicides + autumn soil disturbance → warm season food plants Soil active,pre-emergent herbicides + summer soil disturbance → cool season food plants |
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Strip application |
→ alternating perpendicular strip - treatment at ½ recommended rate Variable rate patterning (VRP) - 3 dosage rates, 0, ½, full. |
