Ecological Methodology
LEC-07
Althoff
Measuring Microhabitat – Part I
Vegetation:
Cover
Species Composition
Bare Ground
Litter Depth
Microclimate:
Temperature
Wind Speed
Net Radiation
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?
•
•
•
•
•
•
•
•
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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 ?
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Terrestrial…yes
Burning
Mowing
Discing
Logging (i.e., clearcutting vs. selective cut)
Other…
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•
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Aquatic…yes
Dredge
Submerge trees, concrete “structures”, etc.
Manipulate water levels, flow, etc.
Other….
Names & Approaches to
Microhabitat Assessment--chronology
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_____________…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 23:295297.
• 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
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)
Looking down
• Toss for random
placement or
systematically place along
line transect
5m
10 m
?
Some are “marked” to help
“sort out” areas of coverage
Daubenmire Frame: % Bare Ground & Veg
0% - 100%
35% - 65%
85% - 15%
5% - 5%
Daubenmire Frame: Cover Classes
Cover
class
Range of Cover Midpoint of Range
0-5%
2.5%
>5-25%
15.5%
>25-50%
37.5%
>50-75%
62.5%
>75-95%
85.0%
>95-100%
97.5%
Daubenmire Frame: Cover Class: Midpoint
6 - 97.5%
4 - 62.5%
2 – 15.5%
1 – 2.5%
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 tall
grass prairie
• “Eye” ______ move…fixed point for each reading
• Distance to pole: recommended _____
Robel Pole
Looking at
down level
Looking at
ground level
• 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
?
View from
overhead
• Generally, “read” from
4 directions (cardinal?)
• Average of _________
used for VOR estimate
for each sample
• Rope usually ____ long
• Read from ____ height
• 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)
4
3.5
3
2.5
2
1.5
1
0.5
0
EAME
GRSP
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
Looking at
down level
Looking at
ground level
• 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
• 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 6
Level 5
Level 4
Level 3
Level 2
Level 1
Nudds Board: Cover Classes
Cover
class
1
Range of Cover
0-20%
2
>21-40%
3
>41-60%
4
>60-80%
5
>80-100%
Example of Data
Height inteval
(e.g. Level 1 = 0-50 cm)
E. Cottontail Rabbit _________ (Rio Grande 2009)
Median Cover Scores
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.
Think Microhabitat for
Bobwhite Quail or Mourning Doves
• What could you measure that is meaningful
to these species using Daubenmire Frame?
1•
Bare ground: more, especially for doves, means
easier ________ to seeds while foraging
2• % Grasses: greater density, especially <1 m might
provide better ______________ of nest for quail
3
• % 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
Wild Turkey
• What could you measure that is meaningful
to these species using Nudds Board?
1•
Vegetation profiles: low-to-moderate cover
estimates at levels <0.5 m indicates easier _______
foraging in summer habitats
2• Vegetation profiles: greater cover estimates in
habitat, especially <1.0 m might provide better
______________ of nesting
3
• Vegetation profiles: very low in mature oak
woodlot suggest well-stocked stand—increasing
________________ predators and access to
__________