Measuring Microhabitat – Part I

Vegetation:Cover

Species Composition

Bare Ground

Litter Depth

Microclimate:TemperatureWind Speed

Net Radiation

Ecological Methodology LEC-07 Althoff

What is habitat?

What is “habitat”...at the _______-level?

• Aquatic – ponds, lakes, streams, oceans

• Marshes, Swamps, Bogs

• Terrestrial – forests, prairies (grasslands), desert, shrubland, etc.

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 diversityusing 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 ofwildlife cover. Wildlife Society Bulletin 5:113-

117.

Measures of VISUAL OBSTRUCTION

• Daubenmire frame

• Robel pole

• Nudds board

___________________________

Daubenmire Frame

Robel Pole

NuddsBoard

Daubenmire

• Was a forester, Pacific northwest• Studied forest/woodland ecosystems• Published in “regional” journal (Northwest Science)

• Assess _________: bare groundvegetation—generalforbs vs. grassesleaf litter vs. live vegetc.

• “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 ?Look

ing

dow

n

Some are “marked” to help “sort out” areas of coverage

Daubenmire Frame: % Bare Ground & Veg

0% - 100%

85% - 15% 5% - 5%

35% - 65%

Daubenmire Frame: Cover Classes

Coverclass

Range of Cover0-5%

>5-25%

>25-50%

>50-75%

>75-95%

>95-100%

Midpoint of Range2.5%

15.5%

37.5%

62.5%

85.0%

97.5%

Daubenmire Frame: Cover Class: Midpoint

6 - 97.5%

2 – 15.5% 1 – 2.5%

4 - 62.5%

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 tallgrass 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 ?Look

ing

at

grou

nd le

vel

Look

ing

at

dow

n le

vel

• Generally, “read” from 4 directions (cardinal?)

• Average of _________ used for VOR estimate for each sample

• Rope usually ____ long• Read from ____ height

Vie

w f

rom

o

ver

he

ad

• 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 amodified 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 DataEastern Meadowlark vs. Grasshopper Sparrow

________ (Ft. Riley, KS 2005) V

OR

(M

ean

+ S

E)

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-? mLook

ing

at

grou

nd le

vel

Look

ing

at

dow

n le

vel

• 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)

Level 1

Level 2

Level 3

Level 4

Level 5

Level 6

Nudds Board: Cover Classes

Coverclass

1

2

3

4

5

Range of Cover0-20%

>21-40%

>41-60%

>60-80%

>80-100%

Example of DataE. Cottontail Rabbit _________ (Rio Grande 2009)

Median Cover Scores

Hei

ght

inte

val

(e.g

. Le

vel 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