Untitled

Page 1

Habitat

Area that promotes:

Occupancy

Survival

Habitat loss is the #1 threat to biodiversity

Habitat loss

Invasive species

Pollution

Population growth of humans

Overharvesting

88% of species listed are endangered because of habitat loss

Fundamental goals of conservation often rest on protecting habitat

Habitat is not synonymous with vegetation

How do you measure habitats?

Dominant plant form

Physical factors?

“habitat type” vs “habitat”

Habitat type is used synonymously with vegetation type

Habitat is more than that, includes more than the plants around it; includes plant, animal, and physical aspects of the environment

Habitat quality

Some habitats are not created equal

Some habitats are more suitable than others

Just because you find an organism in a habitat, it doesn’t mean that is where it will stay or that it can persist there

E.g. norther spotted owl

Normally found in old growth forest

You can find the owls in second growth forest

That doesn’t mean second growth forest is suitable for the owls

Used as an argument against protecting old-growth forest

While the owl can survive in second growth forest, they do not breed in second growth forests.

Habitat selection

Choosing from alternatives

Many species use more than one habitat

Use may change or vary with season, sex, age, resource availability, etc.

Salmon live in freshwater when they are born and then to marine systems later, they go back to freshwater when they breed.

Failure to take these into account has/will lead to ineffective conservation efforts

Habitat Use vs. Habitat Selection

Habitat use: occupation of a habitat in space and time (no implication of choice)

Habitat selection: since not all habitats are created equal, animals have a capacity to choose, or select, among various habitat options

Comparing use vs. availability gives us selection

Keep in mind this choice can be exploratory or learned or it can be innate

Habitat selection template

Innate and/or learned by all organisms

This template provides an individual with a “habitat gestalt”

It is the “ideal habitat” to which an organism is naturally drawn

When people do experiments with animals in the lab giving them a choice between two “habitats”, they are determining which of the choices most closely matches the animal’s template.

If it goes straight to the habitat it is probably innate

If it goes from one habitat to another then it is probably learned

Wecker 1963

Studied habitat preference of deer mouse

In nature, appears to select grassy habitats over wooded habitats

Wecker asked the question, “is this selection innate, or is it determined by experience?”

Raised mice in different environments, then tested them

Concluded: early experience in correct habitat can reinforce this preference. Heredity appears to influence habitat selection. Early experience in wrong habitat cannot override heredity.

Ivlev’s Index of Selection

SI = (U – A)/(U + A)

U = use

A = availability

SI = 0 à use proportional to availability

-1 àcompleted avoidance

+1 à completes selection

Rangeland Conservation

What is a Rangeland?

Dominated by grasses and shrubs

Grasslands, sagebrush, chapparal, steppes, deserts, tundra

Has only recently received conservation attention

In the US, account for 70% of western states

9/13/18

Rangeland Ecology

Compared with other ecosystems, rangelands are poorly understood

Focus on herbivore ecology

Complex and stochastic interactions between root systems, soil, temperature, and rainfall

Lengthy succession and nutrient cycling

Threats and issues

Farming, livestock, mining, recreation

Some of the most degraded habitat in the world

In US, 52% rated by government as either fair or poor condition

Grazing

Range plants adapted to grazing

Retain enough energy in roots to grow back

Overgrazing à not enough leaf area à less photosynthesis à not enough stored energy to regrow

Farming industry (cows overgrazing)

Plants die à erosion, especially along streams

Palatable (tasty) species eaten first

They either die or develop defenses (i.e. toxins)

Replaced by less palatable species

Results in a change in the overall community because the composition of the plants in the rangeland is changing. Plants become less suitable to animal community.

Changes in plant community à change in animal community

Pronghorn antelope need vegetation of a certain height to conceal fawns

Some bird species have specific nesting requirements

Loss of plants à increased evaporation

Trampling compacts soil à increased run-off and reduced infiltration

Becoming more desertified

Disease transmission from livestock to wild animals (hoof and mouth disease, tuberculosis, etc.)

Spread of exotic species

Livestock management

Fencing often used to restrict movements

Can impede wildlife movements

Creates habitat fragmentation

Watering often involves diverting streams

Alters aquatic and rangeland ecosystem

Predator control

Reason why we don’t have nearly as many wolves/mountain lions/coyotes. To protect livestock we eliminate predators. A lot of non-target species are also harmed by poison bait/traps.

Rangeland conservation

Better understanding of rangeland ecology

Especially below the soil

Distinguish between past and present events

Processes occur slowly

Some effects may have occurred before grazing

Incorporate stochastic events

Rainfall can be very irregular: regular droughts, fires

We need to understand the importance of these stochastic events

Think long-term

Manage livestock sustainably and creatively

Minimize impacts on biodiversity

Mimic natural grazers

Grazing Fees

$1.41 per cow and calf, horse, or every 5 sheep (2018)

Grazing fees extraordinarily low

Fees virtually unchanged since 1966

Ranching industry fights back against increasing fees by threatening to pass that cost onto the consumer

Bureau of Land Management (BLM): $15,000,000/year in fees

50% goes to states, 50% goes to habitat improvement

Increased fees could help with restoration and management efforts

Conservation Reserve Program

Started in 1985

Government leases land for 10 years

Landowners paid $50/per acre/per month

Stipulation: give up the right to farming that property

By not farming the land for 10 years it gives the land a chance to recover

As of 2008:

136,000 square kilometers enrolled

700 million tons of topsoil saved

Duck populations up 30%

Other rangeland wildlife up 2-50%

Carbon dioxide sequestration increasing

$39 million in recreational fees to landowners

Land owner allowed to lease that property for hunting

Aquatic Conservation

Failure to protect freshwater ecosystems have resulted in the extinction or endangerment of 20% of the world’s freshwater fish

In North America, 30% of fish are threatened or endangered (364 species)

Habitat loss or degradation is the main cause

Many fish and freshwater invertebrates are found in individual lakes/rivers

Endemism: only found in specific areas

Rivers

Easy targets for dumping

The solution to pollution is dilution (not the case)

Many rivers in industrial areas are so polluted, few species can inhabit them

OHIO: cyahoga river caught fire from so many pollutants

Dams impede movement of some species and change water conditions

Dams result in changes in Flow, temperature, oxygen levels, siltation rates

600,000 miles of river blocked by 75,000 dams in the US

1968 Wild and Scenic Rivers Act. Keeps 10,000 miles of river free flowing

1997: American Heritage Rivers Program. Designates rivers to receive special recognition and support

Receive federal support to restore and improve

9/18/18

Wetlands

Land covered by water for at least part of the year

Definition has varied; usually based on duration of flooding and vegetation

Swamps, mashes, fens, floodplains, prairie potholes, vernal pools

High biodiversity-complex habitat and abundant nutrients

43% of all endangered species in the US spend part of their lives in wetlands

$3 billion in food (crayfish, coastal fish, oysters, muscles, etc.)

$23 billion from recreation (hunting, fishing, boating, wildlife watching, etc.)

$1 billion from logging (have very important hardwood species)

1 million jobs are tied to wetlands

Wetlands: Human Impact

Wetlands often seen as obstacles

Drained or filled for development, agriculture, and transportation

Dredged and channelized for shipping

50% of wetlands have been lost globally

57% of US wetlands lost since colonial times

Ramsar Convention (Iran 1971)

The Convention on Wetlands of International Importance

Framework for wetland preservation and use

160 countries, 1.898 wetland conservation sites

Contracting parties agree to:

Designate and protect at least 1 wetland of international importance

Include wetland conservation in their national land-use planning

Promote wetland conservation, regardless of whether a given wetland is listed

Consult with other nations for assistance, especially if water system is shared

Ramsar Convention: What constitutes a wetland of international importance?

Rare or unique

High biodiversity or supporting rare and endangered species

Important in life cycle

Supports 20,000+ water birds or 1% of population of any given water bird species

Important for fish species

Supports 1% of population of any single non-water bird species

US- 27 sites, 1.5 million ha

Largest one being Chesapeake Bay

Everglades National Park

Okefenokee NWR

Upper MS river floodplain

Clean Water Act (CWA)

1972 – “Restore and maintain the chemical, physical, and biological integrity of the nation’s waters”

Does not explicitly protect wetlands

Section 404- prohibits dredging or filling of navigable waters without a permit

has been broadly interpreted to protect wetlands

Protecting wetlands is the job of the USACE

USACE administers permitting system

Mainly governs filling and discharge into wetlands

Does not govern draining, agriculture, or forestry

Does not address wildlife habitat or flood control

20% of wetlands are not covered at all under CWA

Does not protect wetlands that are less than 12 acres or isolated

Other CWA loopholes

Nationwide 26 Process-fast-track permitting system. Allows draining of 3 acre parcels without threatened and endangered study

Permit #29: Allows for destruction of ½ acre parcels for single family houses. 20,000 acres/year lost

Permit inspections have dropped 40% since 1972 à violations dropped 80%

Suggests that inspections are less rigorous

Due to there being no explicit wetland protection in the CWA

Coral Reefs

Cover 230,000 square miles, mostly in the tropics

Extremely high biodiversity (“The rainforests of the ocean”)

Great Barrier Reef occupies 0.1% of the ocean surface of the world, but it supports 8% of the world’s fish species – six times the number of species found in and equivalent area of the Atlantic coast of the US

Coral reef ecosystems off the coasts of 93 countries have been destroyed or degraded because of several factors

Coral Reefs: Pollution

Coral reefs are very sensitive to pollution

Parts of the Florida Keys coral reef, the continent’s only living barrier reef, are dying at a rate of 10 percent a year

The likely reason is pollution, mainly in the form of nutrients from human sewage and agricultural runoff

Stimulates the growth of algae that overwhelms the reef

Algal blooms

Sediment pollution is also a problem

Increases turbidity à decreased DO

Coral Reefs: Bleaching

Loss of the dinoflagellates that normally live within the coral tissue

Often a function of climate fluctuations

Water temperature increase or decrease

Strong El Nino years (1982-83 and 1987-88) elevated water temperature

In the 1982-83 season 70-90% of the corals in Panama and Costa Rica, and more than 95% of the corals in the Galapagos Islands were killed.

Natural occurrence: as long as it is short term corals recover

Bleaching becomes more frequent and widespread, linked to global warming

Coral Reefs: Poisoning

Cyanide poisoning is being used on an enormous scale in order to stun and capture live fish for Asian restaurants

Customers will pay much more for a fish if it is displayed live before they eat it

A special delicacy, made from the lips of hump-head wrasse, sells for $200 a plate

An estimated 150-400 tons of cyanide are now used each year by fishermen in the Philippines

A lot of organisms are killed, not just stunned by the cyanide

As long as people want live fish the practice will continue to happen

Overexploitation

Exploitation

Harvest for

Food

Fiber (clothing)

Medicine

Scientific/ornamental collection

Exploitation is fine, the issue is harvesting species beyond their ability to recover –overexploitation

9/20

Commercial Overexploitation

High demand

Greed (Tragedy of the Commons)

Unacceptable substitutes

Unacceptable substitutes

Poor regulation and oversight (TOTC again)

Technological capability

Resource value

Ex. Stellars Sea Cow

The ship St. Peter became shipwrecked off Kamchutka in November 1741

They manage to survive by hunting sea cow

The sea cow was estimated to be 28 feet long and 7-8 tons

When the shipwrecked men got off the island on August 1742 they told everyone about the sea cow

Cow was extinct within a few years

Ex. The Great Auk

The Great Auk was a flightless sea bird

It was found in Canada, Greenland, Iceland, Norway, and Great Britain

Animal had few natural predators and no fear of humans so they were easy to hunt

In a matter of a year they were extinct

Greatest threat to Marine Biodiversity?

The sea is the largest source of animal protein used by humans, with most of it from wild stocks

Unlike the land, most animals harvested are from higher trophic levels, which tends to destabilize ecosystems

Many fisheries have collapsed worldwide (Atlantic Cod, Atlantic Bluefin, Tuna, Swordfish, Orange Roughy, several salmon stocks, several shark species, and many more)

90% of all large fish including Tuna, Marlin, Swordfish, Sharks, Cod, and Halibut are gone

The Amphibian and Reptile Industry

Food

Amphibians and reptiles have long been used as a source of protein

Now they are served as a delicacy of oddity for example, frog legs au gratin, frog legs teriyaki

The USA has imported 2.5 million kilograms of frog legs from Japan and India in 1976

Between 1979 and 1987 45000 kgs of alligator were sold every year

In the 1960s 150000 iguanas were eaten per year in Nicaragua alone

12 million fresh water turtles are sold to China from SE Asia per year

Skin

Reptiles and amphibians are used for skins

Reptile skins: shoes, purses, belts

Amphibian skins: shoes, purses, belts, book binding, glue, and fishing lures

Pets

Hong Kong pet trade: importing and exporting salamanders, newts, toads, and frogs from all over the world. Per Year: 34000 fire bellied toad, 9350 Japanese fire bellied newts, etc.

Effects on Non-target Species

Trophic cascades

Bycatch: long drift nets

Mutualists: if you harvest a certain tree you can be harvesting the fungi as well that relies on the tree

Evolutionary Effects

Bighorn sheep in Canada

30 years of data on population pedigree and hunting

Horn length and body size highly heritable

Rams with large, fast growing horns selectively harvested

In the absence of hunting, males with big horns sire the most offspring

With hunting, they sire the least

“unrestricted harvesting of trophy rams has thus contributed to a decline in the very traits that determine trophy quality”

Ginseng

Herbarium records show decline in plants collected 1860-2007

Not only did number decline but plant size declined as well

Bush meat

Increased access to regional/global markets, increased local income, enhanced technology = increased demand and ability to supply bush meat

Rapid depletion of wildlife with potentially devastating consequences for the subsistence of local people and functioning of the forest (seed dispersal, pollination, and fertilization

A Catch 22

When fish supplies are low mammal populations decline

Both fish and terrestrial wildlife are declining, so supply of one can no longer buffer the other

Logistic Population Growth

Maximum sustained yield is at ½ of carrying capacity (K/2)

Total Harvest = total effort x catch per effort

Total effort = # of harvesters

Catch per effort is a function of method (rod and reel vs. drift net)

9/25/18

Exotic species

Exotic invasive, alien non-indigenous

$137 billion + in losses, damage, and control efforts

Threats to biodiversity: habitat loss, invasive species

Environmental tolerances and ecological barriers restrict species distributions

Natural selection acts upon this isolation and it results in unique assemblages of species adapted to that particular area

This is especially true on islands

Humans have altered this pattern by introducing exotic (non-native, invasive) species into new areas

Introduction of European mammals, birds, and plats into parts of Australia, Africa, and North America to make the area seem more like home and to provide known game sources

Many other introductions are accidental

Ship’s ballast often contain seeds and insects in its soil, and water ballast contains phytoplankton and zooplankton

Cargo can also contain exotics. In 1930s a ship from Trinidad landed in Manila carrying 41 species of insects. Examination of ships arriving in Oregon in 1989 found 200+ species of algae and zooplankton

Most introductions fail, even intentional ones

Environmental conditions are too different for them to survive

Those that do survive often flourish as a result of competitive release

Competitive release occurs when a species expand niche in absence of competition

Without native competitors and predators they are able to exploit resources more fully and numbers are less regulated

Some characteristics of successful invaders include the following: high reproductive rate, high dispersal rate, hermaphroditic or clonal reproduction, high variability, habitat and dietary generalist, tolerant of human activity and disturbance

Communities susceptible to successful invasion tend to be the following: similar to the exotics native environment, have low species diversity, absence of invader’s predators, absence of ecologically similar species, absences of predators/grazers in the invading environment ( naïve prey), human presence

I = A * E * R (I = species impact, A = abundance, E = effect per capita, R = range)

Exotic Species Case Studies

Brown tree snake

Accidentally transported from its native New Guinea to Guam during WW2, first discovered on Guam in 1952 (10 year to establish) by 1968 it had spread over most of the island, estimated 1 million snakes and 100,00 people, 13,000 snakes/mi2. Has led to the extinction of most birds on Guam, has caused 1200 power outages, costs $4 million annually in repairs, many bites, not getting seed dispersal with the birds being prey for these snakes, trapping, snake sniffing dogs, the snakes are sensitive to acetaminophen, 80mg will kill them, other wildlife would need to ingest 45000 mg to be lethal, therefore they ae using dead mice with Tylenol injected into them

Purple Loosestrife

Accidentally introduced from Europe and Asia into North America during 1930s, probably arrived in ships and ballast or livestock bedding, by 1985 only Alaska and Montana had no reports of it, rapidly outcompetes native aquatic plants, more than 50% of biomass in some wetlands have been displaced, serious reductions in waterfowl and wetland mammal populations, herbicide, biological control: 120 insects attack loosestrife, 14 are host specific, early results are promising

Zebra Mussels

Native to eastern Europe and western Russia, first found in the Great Lakes in 1988, probably released from ships ballast, reproduce very rapidly, females produce 300,000-1,000,000 eggs/year. They will attach to almost any object, they smother native mussels, they clog intake pipes, serotonin is critical for spawning, methiothepin can inhibit serotonin

Hemlock Wooly Adelgid

Feeds on the needles of all sizes of hemlocks, reduces nutrient movement within the tree and eventually needle death occurs, trees begin to yellow, prematurely lose needles, and stop producing new growth, tree death can occur within 3 – 5 after infestation, trees not killed outright by HWA are susceptible to other diseases and insects. Nearly 36,000 ha of hemlock in the GSMNP, 280 ha of old growth hemlock; the greatest concentration in eastern US, 200 ft tall, they provide food, shelter, and breeding sites across all seasons. 16 of 30 breeding birds were significantly correlated with hemlock, 84% of wood thrush nests in hemlocks, 281 species of insects are associated with hemlocks. Hemlock angle is an obligate moth species found only with hemlocks, spiders are found in larger numbers on hemlocks. Hemlock has been shown to moderate stream temperature summer and winter thereby easing heat and cold stress on aquatic organisms, shade cooling effect from hemlock canopy, loss of hemlocks would increase likelihood of exotic plants becoming established, death of all the hemlocks would increase fire risk. GSMNP is the most visited park, nearly 10 million visitors. Treatments include a soap formula and injecting pesticide into the roots.

10/2/18

Add in notes from google docs

Protected areas

“An area of land and/or sea dedicated to the protection and maintenance of biological diversity and managed through legal and other effective means” (IUCN 1994)

Protect biodiversity and ecological processes

12.5% of Earth’s surface

E.O Wilson book

Types of Protected areas (ICUN)

Strict nature reserves/wilderness areas

Undisturbed

Protection, study, education

National parks

National importance

Scenic

National landmarks

Unique national/natural interest

Managed sanctuaries/reserves

Reserve with human manipulation

Protected Landscapes/Seascapes

Human-nature interaction

Ecological and cultural value

Managed-Resource protected areas

E.g. National Forests

Sustained production of resources

Coasta Rica → 50% under protection (most)

Syria → 0% under protection (least)

Greenland → largest protected park

920,000 km2

5% of protected lands

Only 6% of earth is under strict protection (no human activity/involvement)

What to Protect?

Distinctiveness

Ecosystem with unique species or features

Endangerment

Areas with endangered species

Representation

Areas that are representative of a particular ecosystem

Utility

Species that have human value

Not mutually exclusive

E.g. the everglades represents a wetland ecosystem, it is distinct (w/ unique species) and it is home to many endangered species as well

Reserve Design

Six critical elements for having a successful protected area

Size

Heterogeneity

Shape

Connectivity

Buffer zone

Human activity

Reserve Size

Species area curve

More area = more species

Habitat Quality?

If the habitat has been degraded the species area relationship will be modified

How do we determine the appropriate size?

Extinction-size relationships ( recall island biogeography)

Larger islands contain more species and are more stable

Smaller islands have more turnover (species going extinct and new ones replacing them)

Islands closer to the mainland had more species than more distant islands

Population/single species approach

Home range requirements

Migration requirements

MVP (minimum viable population)

Ne and maintenance of genetic diversity

Edge effects

Temp usually higher at edge because it is exposed

Dryer (bc temp)

Windier

When we fragment an area we reduce the amount of interior and a greater proportion of that fragment is going to be edge. Is the reserve big enough that the edge effects can effectively be minimized?

Disturbance Regime

Is the area big enough that natural disturbances can occur naturally or are humans going to have to manage for it ( i.e. controlled burns)

SLOSS Debate

Single Large Or Several Small reserves

Single large reserves promote:

Home ranges

Interior spaces

Larger populations

Several small reserves promote:

Genetic diversity (more gene flow)

Heterogeneous habitat

Insurance (in the event of a natural disaster one reserve may be knocked out but the others remain untouched with a larger reserve the whole thing could be destroyed-- no backup)

Population studies show that large parks and protected areas in Africa contain larger populations of each species than small parks

2. Heterogeneity and Dynamics

Heterogeneous areas have higher diversity

Patch dynamics

Disturbance patterns

Patch longevity

Alpha (within patch) and beta (between patch) diversity

Presence in a patch is a function of colonization and extinction

Metapopulation

3. Landscape Context

What is the surrounding non-reserve matrix?

Industrial, residential, agricultural

Edge

Administrative boundary is based on political not ecological considerations

False edge = more protection within than without

Biotic vs. legal boundaries

Area-perimeter ratio

Smaller ratio

More edge effect, fewer interior, undisturbed habitats

More management, more cost

10/4/18

Landscape context

What is the surrounding non-reserve matrix

Industrial, residential, agricultural

Edge

Administrative boundary is based on political not ecological considerations

False edge = more protection within than without

Biotic vs legal boundaries

Area perimeter ration

Smaller ratio

More edge effect, fewer interior, undisturbed habitats

More management, more cost

Buffers

Influence land use plans

Human intervention

Direct indirect

Legal and illegal

4. Connecting fragmented habitats

Corridors

Periodic movement

Migration, seasonal movements

Immigration and emigration

Metapopulation

What does a corridor look like?

Line corridor

Entirely edge

Hedgerow, utility strip

Strip corridor

Broader with interior habitat and patch dynamics

An overpass divided highway allows migration safely between two forested areas. (B) Individuals disperse between two large protected areas using smaller protected areas

Natural and Modified elements

Modified landscape elements: roads, fields, industrial zones

Exclusion of modified landscape elements is not possible

Use of landscape elements around natural areas changes

How do we deal with the constantly changing area around protected areas?

5. Buffer zones

Blend protected areas with developed areas – buffer zone

Zoning

Model

Reserve core

Buffer zone (compatible with core goals

Transition zone (can link several reserve systems