Presentation on theme: "Measuring Microhabitat – Part I Vegetation: Cover Species Composition Bare Ground Litter Depth Microclimate: Temperature Wind Speed Net Radiation Ecological."— Presentation transcript:
Measuring Microhabitat – Part I Vegetation: Cover Species Composition Bare Ground Litter Depth Microclimate: Temperature Wind Speed Net Radiation Ecological MethodologyLEC-07 Althoff
What is “habitat”...at the _______-level? Plants - grasses, forbs, trees, ferns, mosses Debris - downed trees, stumps, trash,gravel/stones Leaf Litter - dead leaves various stages of decay Soil - depth, bulk density, texture, pH, etc. Rocks - large, small aggregates Topography - flat, gentle slope, steep, aspect Water - depth, turbidity, pH, salinity, etc. Animals - used by parasites Other ??? consider microclimate & microtopography
What is “habitat”?...towards _______-level Microclimate: Temperature Net radiation Wind speed/velocity Humidity Microtopography: Light penetration Smoothness Etc.
Can we ________ habitat at the micro-level ? Burning Mowing Discing Logging (i.e., clearcutting vs. selective cut) Other… Terrestrial…yes Dredge Submerge trees, concrete “structures”, etc. Manipulate water levels, flow, etc. Other…. Aquatic…yes
Names & Approaches to Microhabitat Assessment--chronology _____________…1959 _____________ et al. …1970 __________… (but “preceeded by DeVos and Mosby 1971) Digital photos…1990’s (see Limb et al. 2009) Low-level aerial photography…2000’s Un-manned aerial vehicles (UAVs)…2010’s ?
3-key papers/contributions Daubenmire, R. 1959. Measurement of species diversity using canopy coverage classes. Northwest Science 33:43-66. Robel, R.J., J.N. Briggs, A.D. Dayton, and L.C., Hulbert. 1970. Relationships between visual obstruction measurements and weight of grassland vegetation. Journal of Range Management 23:295- 297. Nudds, T.D. 1977. Quantifying the vegetation structure of wildlife cover. Wildlife Society Bulletin 5:113-117.
Measures of VISUAL OBSTRUCTION Daubenmire frame Robel pole Nudds board ___________________________
Daubenmire Was a forester, Pacific northwest Studied forest/woodland ecosystems Published in “regional” journal (Northwest Science) Assess _________:bare ground vegetation—general forbs vs. grasses leaf litter vs. live veg etc. “Eye” ____ move to “view” Distance “above” frame ____ vary
Daubenmire Frame Made of metal or PVC ______ x ______ (but some varied from this…up to 0.5 m x 2 m) Toss for random placement or systematically place along line transect 5 m 10 m ? Looking down
Some are “marked” to help “sort out” areas of coverage
Daubenmire Frame Probably “_____” most used (research studies) method in last 30+ years (see handout) If protocol/items recorded are the same, then may have some reasonable expectation that results from one study in one region might be comparable to another even if not the same observers/tech did all the sampling “________ errors probably balance out _______ errors when results from a _____________ are averaged” Daubenmire 1984
Robel and Company Was a biologist (vertebrate), Kansas Studied prairie (grassland) ecosystems Published in “national/international” journal (Journal of Range Management…now Range Ecology and Management) Assess ________:97-99% correlation of height at 4 m to amount of biomass present…in tall grass prairie “Eye” ______ move…fixed point for each reading Distance to pole: recommended _____
Robel Pole Made of metal or PVC ________ with 1 dm (i.e., 10 cm) alternating black and white bands/segments Toss for random placement or systematically place along line transect or within plot >10 m? Looking at ground level Looking at down level
Generally, “read” from 4 directions (cardinal?) Average of _________ used for VOR estimate for each sample Rope usually ____ long Read from ____ height View from overhead First visible band/ segment (i.e., ____ __________ by) vegetation (i.e.,1-15) is recorded
Robel Pole Probably “_______” most used (research studies) method in last 30+ years If protocol the same, then may have _________ reasonable expectation that results from one study in one region might be comparable to another even if not the same observers/techs did all the sampling Original testing/evaluation done in _________ prairie. Has been used in other grassland/shrubland types but generally not validated for those. ____________ (dm) values usually reported, not “true” estimate of biomass
Robel “mods” Some have made bands/segments 0.5 dm. Can therefore record to 1.0 vs. 1.5 vs. 2.0 vs. 2.5….etc. Uresk, D.W. and T.A. Benzon. 2007. Monitoring with a modified Robel Pole on meadows in the central Black Hills of South Dakota. Western North American Naturalist 67(1):46-50. Made first band a 0 (zero)
Example of Data Eastern Meadowlark vs. Grasshopper Sparrow ________ (Ft. Riley, KS 2005) VOR (Mean + SE)
Nudds Was a biologist (vertebrate), Ontario Canada Studied shrubland/woodland ecosystems Published in “national/international” journal (The Wildlife Society Bulletin) Assess ___________:at multiple heights/ layers “Eye” can ______ but recommended “fixed” point, points Distance from board: _________________!
Nudds Board Made of wood _____with ______(i.e., ?? cm) alternating dark and light segments (5-6) Toss “ring” for random placement or systematically place along line transect >1-? m Looking at ground level Looking at down level
Generally, “read” from 1 random direction for each for _____ sample Variable distance _____ board Read from ___ height (or 2 heights ( e.g., lower levels kneeling, upper levels standing) Pictured here was extra pole for distance “away” and height to read (all 1 m)
Nudds Board: Cover Classes Cover class 1 2 3 4 5 Range of Cover 0-20% >21-40% >41-60% >60-80% >80-100%
Example of Data E. Cottontail Rabbit _________ (Rio Grande 2009) Median Cover Scores Height inteval (e.g. Level 1 = 0-50 cm)
Nudds Board Probably “_______________” use (research studies) method in last 30+ years If protocol the same, then still may ___________ ______ reasonable expectation that results from one study in one region will not be comparable especially if the same observers/techs did not do all the sampling Original testing/evaluation done in ________ ______________ hardwood/conifer forests. Has been used in to assess cover in almost every other kind of habitat including cropland
Nudds Board…con’t Distance from board to observer and height (i.e., number of intervals) needs generally to be ________________. For example, taller board makes sense for a larger animal (deer, moose, elk) vs. smaller one (e. cottontail rabbit, snowshoe hare). However, this could vary within ___________. For example, some are ground nesters in forests, others nest 1-2 m above ground, others higher up yet.
Nudds Board…con’t Issue with pushing “% coverage” into a _______ ______________ For example: 18% not that different from 21%. Former scores a “1”, latter scores a “2”. Best way to improve consistency—from the start is to do ________ readings. For example, take samples from 5 points. Read all levels at each, then repeat. Compare estimates. If fairly consistent then reasonable to start sampling in earnst.
What could you measure that is meaningful to these species using Daubenmire Frame? Bare ground: more, especially for doves, means easier ________ to seeds while foraging % Grasses: greater density, especially <1 m might provide better ______________ of nest for quail % Coverage of Plants: low to moderate %, especially < 1 m high might indicate whether quail chicks (1-3 weeks old) can easily ______ through the vegetation to forage for ____________ Think Microhabitat for Bobwhite Quail or Mourning Doves 1 2 3
What could you measure that is meaningful to these species using Nudds Board? Vegetation profiles: low-to-moderate cover estimates at levels <0.5 m indicates easier _______ foraging in summer habitats Vegetation profiles: greater cover estimates in habitat, especially <1.0 m might provide better ______________ of nesting Vegetation profiles: very low in mature oak woodlot suggest well-stocked stand—increasing ________________ predators and access to __________ Think Microhabitat for Wild Turkey 1 2 3