Biodiversity. Why is Biodiversity Important? Genetic diversity:

Preview:

Citation preview

Biodiversity

Why is Biodiversity Important?

• Genetic diversity:

Why is Biodiversity Important?

• Species Diversity:

Why is Biodiversity Important?

• Ecosystem Diversity:

Diversity = Richness + Evenness• richness: count of # species

• evenness: relative abundance of speciesEcosystem A Ecosystem B

4 oak species 3 oak species

bl oak = 40 bl oak = 120

wh oak = 30 wh oak = 60

r oak = 20 r oak = 20

pin oak = 10 pin oak = 0

A = B = alpha () diversity – within habitatC = beta () diversity – among habitatD = gamma () diversity – geographic scale

Three Scales of Diversity

Alpha & Gamma Species Diversity Indices

• Shannon-Wiener Index – most used

- sensitive to change in status of rare species

s

iii ppH

1

))(ln('

H’ = diversity of species (range 0-1+)

s = # of species

pi = proportion of total sample belonging to ith species

Alpha & Gamma Species Diversity Indices

• Shannon-Wiener Index

s

iii ppH

1

))(ln('

Alpha & Gamma Species Diversity Indices

• Simpson Index – sensitive to changes in most abundant species

s

iipD

1

2)(1

D = diversity of species (range 0-1)

s = # of species

pi = proportion of total sample belonging to ith species

Alpha & Gamma Species Diversity Indices

• Simpson Index

s

iipD

1

2)(1

Alpha & Gamma Species Diversity Indices

• Species Evenness

max'

'

H

HJ

H’max = maximum value of H’ = ln(s)

Beta Species Diversity Indices• Sorensen’s Coefficient of Community

Similarity – weights species in common

cba

aSS

2

2

Ss = coefficient of similarity

(range 0-1)

a = # species common to both samples

b = # species in sample 1

c = # species in sample 2

Beta Species Diversity Indices• Sorensen’s Coefficient of Community

Similarity

Dissimilarity = DS = b + c / 2a + b + c

Or 1.0 - Ss

Species Sample 1 Sample 2

1 1 1

2 1 0

3 1 1

4 0 0

5 1 1

6 0 0

7 0 0

8 1 0

9 1 1

10 0 0

11 1 1

12 0 0

Sorensen’s Coefficient• Sample 1

– Total occurrences = b = 7- # joint occurrences = a = 5

• Sample 2– Total occurrences = c = 5- # joint occurrences = a = 5

• Ss = 2 * 5 / 10 + 7 + 5 = 0.45 (45%)

• Ds = 1 – 0.45 = 0.55 (55%)

Species-of-the-Week

American woodcock (Scolopax minor)

Habitat

• Woods & thickets with moist soil, small openings near woody cover

• aspen, alder, willow cover types (early successional = seedling/sapling stage; <3 in dbh)

Food

• Diet = 50-90% earthworms

• Diurnal foraging in spring/summer

• Nocturnal foraging in winter

• Long bill used as probe (foot stomping)

Reproduction

Courtship behavior = males on breeding fields Mar-Apr -- polygynous

Clutch size = ~4 eggs

I.P. = 21 days; near full grown in 28 days

Behavior

- Migratory – winters in SE U.S.

- Nonvocal calls = wing position

Estimating Abundance of Wildlife

• Terms

- Population

- Relative vs. Absolute Abundance

- Parameter vs. Statistic

- Population Index- Accuracy

- Precision

- Bias

Estimating Abundance of Wildlife

• Complete Counts (Census)

- open habitat = visible wildlife

- concentration of activity

- small study area

Estimating Abundance of Wildlife

• Complete Counts (Census)

- Drives

* Biased (under- or overestimate)

- Territorial (Spot) Mapping

e.g., breeding birds

Territorial (Spot) Mapping

Limitations:- territorial species (grouse, songbirds)- sex ratio known or

assumed-nonterritorial males? (floaters)-ability to id species & map territories

Estimating Abundance of Wildlife

• Complete Counts (Census)

- Aerial Counts & Sensing

- must see animal to count it!

- Aerial Photos or IR Thermal Scans

- photos of migratory waterfowl

Estimating Abundance of Wildlife

• Complete Counts (Census)

- Aerial Counts & Sensing

• Aerial line-transect counts

- must see animal to count it!

• Aerial Photos or IR Thermal Scans

- photos of migratory waterfowl

- IR scans of wildlife (bowhunting study in MN – loss rate)

Estimating Abundance of Wildlife

• Complete Counts - Sample Plots

- Line transects (ground or aerial)

- e.g., flush count for grassland birds

- assumes 100% detection

Indices of Relative AbundanceIndices of Relative Abundance• …dependent on the

collection of samples that represent some relatively constant but unknown population size

– Traps, number of fecal pellets, vocalization frequency, pelt records, catch/unit effort, number of artifacts, questionnaires, cover, feeding capacity, roadside counts

Indices of Relative AbundanceIndices of Relative Abundance

Capture TechniquesCapture Techniques

Capture TechniquesCapture Techniques

Radio Telemetry

Female

Male

Spatial Organization

Scent Stations

Remote Camera Systems

DNA Fingerprinting

GPS

Recommended