Download Principles of Conservation Biology, Third Edition

Biodiversity Patterns and Processes
Conservation Biology focuses on the study and
preservation of biodiversity! Some definitions…
The applied science of maintaining the earth’s biological diversity (Hunter 1996).
An emerging synthetic discipline that deals with the basic issue of eroding biological
diversity (Temple et al. 1988).
Treats the content of biodiversity, the natural processes that produce it, and the
techniques used to sustain it in the face of human-caused environmental
disturbance (Wilson 1992).
The effort to retain the actors in the evolutionary play and the ecological stage on
which it is performed (paraphrased after Hutchinson 1965)*
The application of biology to the care and protection of plants and animals to
prevent their loss or waste (Salwasser 1994)
*The Ecological Theater and the Evolutionary Play
Biodiversity
More Select Definitions •
•
•
•
sum total of all living things
richness and variation of the living world
variety of life and its processes
variability among living organisms from all sources (marine,
aquatic, terrestrial) and the ecological complexes of which they
are a part (Convention on Biological Diversity Rio Summit)
• variety of species and ecosystems on Earth and the ecological
processes of which they are a part (Canadian Biodiversity Strategy)
< 1% of all species have been described by science
~estimated 10-12 million species
Does species diversity = biodiversity?
Not necessarily!
Biodiversity is more than a species numbers
game!
Quality often more important than quantity!
The important task is to not so much to define biodiversity, but in
any given defined area to:
• Determine biodiversity components (organisms), distribution
(where it occurs), interrelationships, threats, monitoring and
measurement criteria, and conservation strategies and measures
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•
•
•
Landscape
Community/Ecosystem
Species/Population
Genetic
Decreasing
Complexity
Biodiversity (Spatial Scales of Measurement)
REALM
BIOME
ECOREGION
LANDSCAPE
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
GENETIC
Earth’s Biogeographic Realms:
Large regions within which
ecosystems share a broadly
similar biota. Mostly terrestrial
and freshwater oriented –
marine realms are poorly
defined.
Oceanic
Antarctic
Australasian
Nearctic
Neotropic
Palearctic
Afrotropic
Indo-malay (note Wallace’s Line)
REALM
BIOME
ECOREGION
LANDSCAPE
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
GENETIC
Earth’s Biomes:
Broad habitat and vegetation
types that span biogeographic
realms.
2.4 Biomes and climate
Biomes
% Biomes Conserved/Protected
% protected
Tropical & sub-tropical moist broadleaf forests
5.5
Tropical & sub-tropical dry broadleaf forests
4.9
Tropical & sub-tropical coniferous forests
2.5
Temperate broadleaf and mixed forests
3.8
Temperate coniferous forests
8.9
Boreal forests/taiga
6.3
Tropical & subtropical grasslands, savannas, & shrublands
5.5
Temperate grasslands, savannas, and shrublands
1.9
Flooded grasslands and savannas
8.7
Montane grasslands and shrublands
3.8
Tundra
13.7
Mediteranean forests, woodlands, and scrub
2.8
Deserts and xeric shrublands
3.7
Mangroves
8.6
Which are the least and most protected and why?
From: Millenium Ecosystem Assessment 2005 (Island Press)
REALM
BIOME
relatively large area, dominant assemblage of
species, communities, and conditions
ECOREGION
LANDSCAPE
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
GENETIC
867 Terrestrial Ecoregions (WWF)
(US Environmenatal Protection Agency class types I-IV
Ecoregions)
– I = 15
– II = 52
– III = 104
– IV = hundreds (under revision)
• Kentucky is in 1 Biome: Temperate Broadleaf and
Mixed Forest
• KY is in 3 Broad Ecoregions (according to WWF)
- Appalachian Mixed-Mesophytic Forests
- Central U.S. Hardwood Forests
- Mississippi Lowland Forests
Kentucky’s Traditional (i.e. what you find in most literature)
Major Ecoregions (non-EPA)
REALM
BIOME
ECOREGION
LANDSCAPE
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
GENETIC
Repeated pattern of
interacting ecosystems
(e.g. Inner Bluegrass)
Landscape Example: Bluegrass Region of Kentucky?
Savanna-Woodland-Meadow Landscape of Bluegrass Region of KY
“The flats on either side of the river were crowded with immense
herds of buffalo…and a number of elk were seen on the bare
ridges which surround a spring.”
- Simon Kenton 1771
Savanna-Woodland-Meadow Landscape of Bluegrass Region of KY
Generally “well-timbered”?
The land is light with timber, little oak- mostly
sugar tree, walnut, ash, buckeye…
- 1775
The land is so good I cannot give it due praise.
It’s timber is honey locust, black walnut,
sugar tree, hickory, ironwood, mulberry,
ash, elm, and some oak.” - 1781
“The Elkhorn lands…soil is deep and black, and
the natural growth, large walnuts, honey
and black locust, poplar, elm, oak, hickory,
and sugar trees.” - 1789
Savanna-Woodland-Meadow Landscape of Bluegrass Region of KY
“There are many canebrakes so thick and tall
that it is difficult to pass through them, and a
man on horseback could easily get lost.”
“The canebrake where my father settled on
Cane Ridge in Bourbon County extended for
20 miles.”
-John Filson 1781
“A canebrake extended for almost 6 miles
from Lexington to Walnut Hill Church”
• Winchester, Georgetown, and Versailles
settled in the midst of canebrakes.
• Historically (~1790), the diverse timber cover, cane, and
meadow descriptions suggest a landscape mosaic/complex in the
Bluegrass Region of central Kentucky
REALM
BIOME
ECOREGION
POPULATION/SPECIES
GENETIC
LANDSCAPE
ECOSYSTEM
COMMUNITY
Biotic community and
abiotic environment.; Often
have complex food (trophic)
webs and “self-contained”
nutrient cycles such as
nitrogen cycle
Mixed-Mesophytic Forest Ecosystem (eastern U.S.)
2.3 Large marine ecosystems of the world and their associated major watersheds
Chihuahuan
Desert
Ecosystem
(southwestern U.S.)
Typical (simplified)
Ecosystem Trophic
Model (as portrayed from the bottom up)
What is a primary producer, primary
consumer, secondary consumer,
tertiary consumer, and detritivore?
Omnivore – eats both plants and
animals
Herbivore – eats plants only
Carnivore – generally solely a meat
eater, or of the Order Carnivora
Scavengers – eat dead animals
Parasites – obtain nutrition from by
living inside or on another organism
REALM
BIOME
ECOREGION
POPULATION/SPECIES
GENETIC
LANDSCAPE
ECOSYSTEM
COMMUNITY
Interacting assemblage of
species in a defined area
For Example: Biotic Communities at
Lexington Cemetery
Examples major taxa:
Animal Community: House Sparrow, Northern Cardinal, Cooper’s Hawk, Canada Goose, Carolina
Chickadee, House Finch, Blue Jay, raccoon, Virginia opossum, eastern box turtle, spring
peeper, bullfrog, garter snake, Misc. insects and invertebrates
Plant Community: American Basswood, KY Fescue 31, Bush honeysuckle, Winter creeper,
Northern red oak, Gingko, Black walnut, Broom sedge, multiflora rose, Colorado blue
spruce, Virginia pine, bur oak, blue ash, spring beauty, blue phlox
Fungi: Molly’s eyewinker, golden trumpets, artist’s conk, angel-of-death, elegant stinkhorn
Or Could add all these together for the total biological community…or whatever category you
wanted to include as a community (e.g. the vertebrate community, or herpetological
community) there are many ways to categorize “community”.
Guild/Functional
group – use
resources in
similar ways but
partition the
resources by
space and time.
In this example:
large herbivores
LANDSCAPE
ECOSYSTEM
COMMUNITY
POPULATION/SPECIES
GENETIC
Population- is local occurrence individuals
of the same species; typically the unit of
management used to maintain viability in
natural patterns, abundances, and
distributions (e.g. the cheetah population of
the Serengeti ecosystem, or the elk
population in Kentucky).
LANDSCAPE
ECOSYSTEM
• Best known level of biodiversity
• 1.8 million known species, 10-100 million
are estimated, and 300/day are being
discovered
• Species Richness = # species/unit area
COMMUNITY
POPULATION/SPECIES
GENETIC
The hierarchy
of biological
classification
Biodiversity and the Definition of Species
Morphological Species = (Morphospecies) groups distinctive based on observable morphological
characteristics; commonly used by botanists
Biological Species = (Biospecies) = groups with interbreeding individuals but reproductively
isolated from other groups (Mayr 1969)
Genetic Species = are separated according to genetic differences; thus far, highly subjective
and changing
Cladistic Species = Species separated according to cladograms. Each branch is a new species
usually with traceable ancestral linkages.
Biodiversity and the Definition of Species
Morphological Species = (Morphospecies) groups distinctive based on observable morphological
characteristics; commonly used by botanists
Biological Species = (Biospecies) = groups with interbreeding individuals but usually
reproductively isolated from other groups (Mayr 1969); interbreeding can occur between
some species but behavioral barriers or physical size differences or incompatibilities usually
prevent this.
Genetic Species = are separated according to genetic differences; thus far, highly subjective
and changing
Cladistic Species = Species separated according to cladograms. Each branch is a new species
usually with traceable ancestral linkages.
Biodiversity and the Species Concept
Morphological Species = (Morphospecies) groups distinctive based on observable morphological
characteristics; commonly used by botanists
Biological Species = (Biospecies) = groups with interbreeding individuals but reproductively
isolated from other groups (Mayr 1969)
Genetic Species = are separated according to genetic differences; thus far, highly subjective
and changing
Cladistic Species = Species separated according to cladograms. Each branch is a new species
usually with traceable ancestral linkages.
Biodiversity and the Definition of Species
Morphological Species = (Morphospecies) groups distinctive based on observable morphological
characteristics; commonly used by botanists
Biological Species = (Biospecies) = groups with interbreeding individuals but reproductively
isolated from other groups (Mayr 1969)
Genetic Species = are separated according to genetic differences; thus far, highly subjective
and changing
Cladistic Species = Species separated according to cladograms. Each branch is a new species
usually with traceable ancestral linkages.
2.2 (A) Domains of biodiversity: Bacteria, Archaea, and Eukarya
?
Phylogeny – hypothesis that describes the history of evolutionary
descent of a group of organisms from its common ancestor
Cladogram is the structure typically used to illustrate phylogenetic
relationships
2.2 (C) Major groups of animals
Morphological, developmental, physiological, behavioral,
molecular traits are used to construct phylogenies.
LANDSCAPE
ECOSYSTEM
Genes – functional unit of heredity,
fundamental unit of biodiversity
COMMUNITY
POPULATION/SPECIES
GENETIC
• Species differ in gene frequencies and
genotypes
• genetic material is the raw material of
evolution
Biodiversity and the Definition of a Species
•
2 most commonly used definitions are:
Morphological Species
Biological Species
•
Why?
•
•
•
Testable and operational
Compatible with legal concepts inherent in conservation laws
Focus on a level of biodiversity that is a familiar, traditional expressions
of conservation and management
Biodiversity Characteristics/Indicators. What are 3
important ways to visualize/describe biodiversity?
Biodiversity (Characteristics/Indicators; 3 important
ways to describe)
1. Compositional (the living parts)
2. Structural (how the parts are arranged in the “house”; note
often the living parts comprise part of the house)
3. Functional (what work/job does it perform?)
Geologic Time and Biodiversity –
How old is Earth?
Is biodiversity increasing over time?
How are new species produced?
Geologic Time, Extinction, and Biodiversity
How old is Earth?
Is biodiversity increasing over time?
How are new species produced?
Extant – still exists
Extinct – no longer exists (spatially defined)
• Global extinction – absent from Earth
• Local extinction – absent from defined place
• Ecological extinction – usually refers to an extant
species, but is at such low numbers to be functionally
extinct
2.5 Diversity of marine families from the Cambrian to the present
2.6 Terrestrial plant species richness
High rates of speciation (formation of new species)
favored by:
• Mass extinctions
• Major land separations
• Evolution of new life forms
• Types of Competition (increased complexity usually = increased
speciation/richness)
A good rule of thumb is biodiversity
begets more biodiversity.
Extinction Events
1) Ordovician-Silurian: 450 myb; 100
marine families were lost
(brachiopods, trilobites, etc.)
2) Devonian: 364 myb; all agnathan
(jawless) fish lost
3) Permian: 250 myb; Earth’s most
severe extinction event (96% of
marine species, 70% of terrestrial
vertebrates): corals, reptiles, land
plants – continental drift?
4) Triassic-Jurassic: 200 myb; many
amphibians and marine families
lost, half of all species on Earth.
Caused by volcanic gases?
5) Cretaceous-Tertiary (K-T Boundary):
65 myb; dinosaurs, 17% of sessile
marine invertebrates, freshwater
mollusks; led to the rise of
mammals. Asteroid impact.
2.7 Extinctions of families through geologic time
Major extinction events can
create a 10 million year or
more lag in biodiversity
“norms”
LATE PLEISTOCENE EXTINCTION
~ 15,000 years ago (ya);
(A “mini-extinction” event; in the scheme of geologic time)
Painting by Mauricio Anton, in The Big Cats and their Fossil Relatives, Columbia University Press. 1997.
Extinct
living large
large (>45kg)
(>45kg) mammals
mammals of
of the
the late
late Quaternary
Quaternary (N.A.)
(N.A.)**
& living
Extinct &
Glyptodont
American mastodon
Mountain deer
Big-tongued ground sloth
Columbian mammoth
Woodland caribou
Jefferson's ground sloth
Dwarf mammoth
Moose
Shasta ground sloth
Jefferson's mammoth
Wapiti
Dire wolf
Woolly mammoth
Pronghorn
Gray wolf
Mexican horse
Pleistocene mountain goat
Black Bear
Western horse
Mountain goat
Brown Bear
Pleistocene tapir
Bighorn
Giant short-faced bear
Western camel
Shrub ox
Saber-toothed cat
Long-legged llama
Bonnet-headed musk ox
American lion
Long-nosed peccary
Musk ox
Jaguar
Flat-headed peccary
Pleistocene bison
American cheetah
Mule deer
American bison
Mountain lion
White-tailed deer
* from Martin & Burney 1999
WildEarth
Current rates of species extinctions are very high, above
background extinction rates, and approximate a 6th
major extinction event. The era of human population
growth and modification of the planet on a global
scale, including causing the loss of biodiversity, has
been unofficially dubbed the “Anthropocene” era.
http://en.wikipedia.org/wiki/Anthropocene
Five Minute Drill:
1) What scalar units (scale) can biodiversity be
measured in? What is the most common unit used,
and why?
2) Biodiversity patterns over time…describe the general
trends and major influences.
3) What is our general state of knowledge about
biodiversity?
4) If all species go extinct, then why are we worried
about the loss of biodiversity?
Biodiversity patterns
• Not uniformly distributed
• Need to know where to
preserve and manage it!
• GIS and models are now
commonly used tool to study
biodiversity
Describing Biodiversity patterns
What is endemic?
Species Richness?
What is a biodiversity hotspot?
Madagascar
•
•
Long-isolated from other continents
Extremely high endemism; ~80% of all
animals and plants are endemic, 90% of all
plants!
– Often referred to as the “8th continent” its
so biodiverse.
Box 2.1 (A) Hot spots or rarity and species richness in the lower 48 United States
Rarity-weighted
richness index (RWRI)
Global Biodiversity Hotspots
Species richness is greatest in tropical ecosystems
Tropical Rain Forests
•
•
•
7% Land area but > 50% world’s species
5-30 million insect species
40% of all plants
Coral Reefs
•
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“tropical rain forest” of the ocean
High productivity (2500 g/m2/yr vs. 125
g/m2/yr in open ocean)
Example Great Barrier Reef is 0.1% of ocean
are but supports 8% of all fish species
Global Biodiversity Hotspots
2.10 The Indo-West Pacific is a marine diversity hotspot
Why are tropical ecosystems so biodiverse?
Some theories include:
1. High solar energy and rain = high primary productivity
2. Relatively long-term stable environment vs. temperate ones
3. Warm temps and high humidity support more available niches
(e.g. tree canopies) and speciation; little to no energy goes into
special behaviors or adaptations to withstand drought, freezing
temps, or having to migrate.
More Biodiversity Patterns
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•
•
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Latitudinal Gradients
Disturbance Gradients
Area/Size Relationships
Other predictors
2.11 Latitudinal species richness in bivalve mollusks
2.12 Latitudinal gradients of species richness of birds and mammals in North and Central America
Box 2.1 Table A
More Biodiversity Patterns
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•
•
•
Latitudinal Gradients
Disturbance Gradients
Area/Size Relationships
Other predictors
2.18 Model of the intermediate disturbance hypothesis
intermediate disturbance hypothesis:
largely based on woody species models
Old Growth Forests and Biodiversity
•
Some models suggest that biodiversity reaches its maximum at
the end of the life expectancy of old growth forests. Why?
• Large trees at maximum height provide more structural and
microclimatic diversity than young ones. More snags,
biomass total, deadfall, biomass, with establishment of
multiple species of wildlife, fungi, invertebrates, non-woody
plant species, and microorganisms than younger forests
More Biodiversity Patterns
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•
•
•
Latitudinal Gradients
Disturbance Gradients
Area/Size Relationships
Other predictors
More Biodiversity Patterns
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•
•
Latitudinal Gradients
Disturbance Gradients
Area/Size Relationships
Other predictors
Island Formation:
Land-Bridge versus Volcanic/Oceanic Islands
Land Bridge Island
Forest
Uncut
Cut
Volcanic/Oceanic Island
Ocean
Volcanic
Activity
New Island
Lexington’s forest
“islands” in a sea of
urbanization; examples of
Land Bridge Islands
Some Examples of Island Types
National Parks and other
Protected Areas:
often become a managed
island due to high contrast
with surrounding lands;
these lands can thus
Land-bridge islands, in behave as islands by
this case created by a influencing movement of
dam at Barro Colorado species
Island Nature Preserve
Mangrove Island
near Florida is an
oceanic island, so
is all of Hawaii
created by volcanic
activity
Theory of Island Biogeography
Distance to island or nearest
habitat patch
A
B
Mainland (or nearest
habitat patch)
C
D
size
The size of the island and the distance to
the mainland or nearest habitat patch
determine how many species can be
maintained on any given island or
habitat patch; i.e. there are only x
number of available niches that can be
occupied by organisms
Island Formation:
Land-Bridge versus Volcanic/Oceanic Islands
Land Bridge Island
Relaxation – gradual loss of species over time
following isolation of an island or habitat patch;
eventually reach dynamic equilibrium; what
happens when chunks of land are cut off from a
“mainland”; applications to parks and other
protected area management
Volcanic/Oceanic Island
During formation of new islands
you see increase in # species over
time until colonization and
extinction processes reach
dynamic equilibrium
Species-Area Relationship Theory of Island Biogeography
(MacArthur and Wilson (1967)
S = CAz (S = # species on island, A = area of the island, C and Z are constants determined by
(Z) movement ability (restricted versus highly mobile) and (C) typical species numbers values for
taxa (abundant vs. less abundant)
Each of these points represent a dynamic
equilibrium between colonization and extinction!
Understanding island biogeographic
theory is important for
understanding forestry and
management of other habitats, as
well as the functionality of national
parks and other protected areas;
here we can unfortunately see that
the loss of rainforest on the
biodiverse island of Sumatra from
deforestation has created a series of
increasingly smaller islands that can
sustain an much smaller amount of
biodiversity than only 100 years
ago. Many species in these islands
are classified as the living
dead…those organisms stranded on
these forest islands with relatively
low numbers to maintain themselves
Calculating the number of species for a given group of
organisms (e.g. birds) on different island sizes.
S = CAz If C =1 and Z = 0.25 what is the predicted # of
bird species for islands that are 10, 100, 1000, and
10,000 km2 in size?
The answers are 2, 3, 6, 10
Topography (“3-D effect” creates unique microclimatic effects and
vertical structuring that can lead to isolation, new niches, and speciation)
Topography (“3-D effect” creates unique microclimatic
effects and vertical structuring that can lead to isolation, new
niches, and speciation)
Identifying Species Impacts on Ecosystems:
Some Terminology on Relative Ecological Importance
Habitat Generalists – can exploit a variety of habitats within an
area/range; can easily switch from available and/or preferred to less
preferred habitats
Examples: White-tailed deer, elk, raccoon, bluegill, white oak
Habitat Specialists – can exploit (usually very well) 1 or only a few habitats
within an area/range; most habitats unsuitable and cannot be used
Examples: Kirtland’s warbler, running buffalo clover, desert
pupfish,
red-cockaded woodpecker
Ecosystem Services – What are they?
• Why do we need to qualify and quantify
them?
What components of biodiversity are necessary for ecosystem function?
How does removing 1% of species make a difference?
2.19 Ecosystem function could increase quickly with species richness
Rivet/Redundant
Top-Down Regulation by Carnivores
Ecological Release
Strong Ecosystem Influence
Dominant Species
Keystone Species
Ecosystem Engineers (Special Keystones that
modify habitats on large scales)
Weak Ecosystem Influence
Common Species
Rare Species
2.20 Ecosystem function can be influenced by the functional diversity among species
2.1 Linguistic diversity and numbers of indigenous cultures across the world (Part 1)
2.1 Linguistic diversity and numbers of indigenous cultures across the world (Part 2)
Basic Measurements of Biodiversity
Alpha, Beta, and Gamma Diversity
Calculating Species Alpha Diversity (Species Richness)
Site 1
Site 2
Site 3
House sparrow
Elegant Trogon
Canyon Wren
European Starling
Bicknell’s Thrasher
Northern Cardinal
House Wren
Lucy’s Warbler
American Crow
Northern Cardinal
Anna’s Hummingbird
Common Raven
Chimney Swift
Painted Redstart
Red-tailed Hawk
Mountain Chickadee
Richness = # species/unit area
Which site has the highest species richness?
Evenness (measure of relative/abundance)
Site 1
House sparrow
Site 2
60
150
European Starling 50
10
House Wren
45
15
Northern Cardinal 60
5
Chimney Swift
25
50
Which site has the highest species richness?
Measuring Alpha Diversity
Walnut Woods
McConnell Springs
Blue Jay
Blue Jay
Cardinal
Cardinal
Carolina Chickadee
Carolina Chickadee
Blue Jay
Site A
Site B
Which site has the highest species richness?
Measuring Alpha Diversity
Palisades
Bluegrass Upland
Bluegrass Canebrake
Blue Jay
Blue Jay
Black Vulture
Cardinal
Cardinal
Cardinal
Carolina Chickadee
Carolina Chickadee
Whipporwill
Blue Jay
Blue Jay
Site A
Site B
Site C
Which site has the highest species richness?
Describing Biodiversity patterns
Gamma Diversity – # species across larger landscape gradients/collection of
sites
• Usually refers to denote diversity of communities within a landscape
• Can also be thought of as a species turnover rate with distance between
similar habitat or with expanding geographic area
• Can be calculated as follows:
γ = S1 + S2 − c
where, S1= the total number of species recorded in the first community, S2= the total
number of species recorded in the second community, and c= the number of species
common to both communities (see handout for more description)
.
Describing Biodiversity patterns
Beta Diversity – rate of change in spp. across/among habitats or
communities; 1st approximation of regional diversity
• S/alpha
or alternatively
S/alpha-1
where S = # species in entire set of habitats
where alpha = mean # species per site
Stick w/ the first formula S/alpha in this course
• = gamma diversity/mean alpha diversity
• Rate of change determined by 1) species range size, 2) habitat specialization
• High with distinct habitats with distinct species, low when the same spp. found throughout
the region.
• Inversely proportional to average geographic range size of a collection of species in a
given area
• See handout for additional explanation and ways to calculate
2.9 Species turnovers along habitat gradients (Part 1)
Here you can see that as the habitat gradient (the difference or
contrast between neighboring habitats) goes up, then that sharp
difference provides more ecological niches for many species in a
relatively short amount of geographic space thus leading to a
rapid increase in beta diversity.
Thinking about the 3 standard scales for measuring biodiversity (alpha, beta, gamma)