Biol 201 Lecture 19 Communities_2

8/18/2019 Biol 201 Lecture 19 Communities_2

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Communities: who, how many,

and how do they interact?

What is community ecology?

The Python Challenge in Florida

Keystone species

Succession

Impacts of Brown Tree Snake Invasion in Guam

• Extirpation of 8 of 11 species of native

forest birds

• Decimated other vertebrate species,

including flying fox (a bat) and half oflizard species

• Dramatically altered existing food

webs

(Wiles et al., 2003)

Collapse of native birdsWhat is community ecology?

1. Why do some areas have many more

species than others?

2. Why are some species common while

others are rare?

3. How do the species interact?

What is community ecology?

4. Are some species more important than others

in structuring the community?

5. What will happen when a new species is

introduced?

6. Why and how do communities change

through time and across space?

What species are there? Species Richness.

Step 1 of being a community ecologist:

Figure out what species are in the community.

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=KSIb6zTYnS2aPM&tbnid=4PBU-daOVhM1lM:&ved=0CAUQjRw&url=http://sensingnature.co.uk/education/176-2/&ei=nsI3UceOHoOzqQGul4CACg&psig=AFQjCNGohpPJsLTgKgW9e-P7U-DcmOUpGA&ust=1362695147477399http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=QoiSZMdNsEem5M&tbnid=oVriTrfI4aMUfM:&ved=0CAUQjRw&url=http://geographywiki.wikispaces.com/Don+Pipping&ei=OsI3Ub-RGMTErQHixYGoAg&psig=AFQjCNGyIXqCgcpUV4qIhcuFivGJYsaBJA&ust=1362695081069445http://en.wikipedia.org/wiki/File:Snake_browntree.jpghttp://en.wikipedia.org/wiki/File:Boiga_irregularis_coiled.jpg


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Species richnessRichness: (S)

a count of the number

of species present in

an area.

TREES

Species richnessWhite spruce

Trembling asp en

Balsam poplar

Ponderosa pine

White spruce

Douglas Fir

Whitebark pine

Western larch

Lodgepole pine

Black cottonwood

Trembling aspen

Silver fir

Grand fir

Subalpine fir

Paper birch

Western redcedar

Mountain alder

Engelmann spruce

Western white pine

Black spruce

Douglas maple

Green alder

Sitka alder

Water birch

. . .and more. . .

3 species

~65 species

How many of each species are there?

Species evenness, diversity indices, dominantsStep 2 of being a community ecologist:

Figure out how many of each species are in the community.

(yep, big task is how to count things).

pitfall trap for dung beetles

How common are the different species?

Dominance and evenness

Durães et al. 2005. Neotropical Entomology 34:721-731

Dominance and evenness: there’s math

for that

Simpson’s Diversity Index

D = Σ(ni/N)2

ni = number of individuals of species i

N = number of individuals of all species

D close to 1 : one species dominates

D close to 0 : few individuals each of

many species (more even)

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=0RFFdHsjopNM1M&tbnid=JP8hicsZs7J83M:&ved=0CAUQjRw&url=http://sites.sinauer.com/ecology2e/ccc23.1.html&ei=D7g3Uc68PIaAqgGaroDoCQ&bvm=bv.43287494,d.aWM&psig=AFQjCNHliyFf9J4ehRGGwIhFwgdqqNFr4g&ust=1362692490670692http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=W3-uoGd_IeOyQM&tbnid=0ab3HC8aOocyJM:&ved=0CAUQjRw&url=http://www.coleoptera-neotropical.org/paginas/2_PAISES/Argentina/scarab_arg.html&ei=OcE3UfTnMIXyqAGokIHQBA&psig=AFQjCNHgSpEB_7szT1_FfwL7N2bTRG3voA&ust=1362694827369509http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=T1ajYLX8JW99pM&tbnid=jqM-U41LdI5INM:&ved=0CAUQjRw&url=http://www.americaninsects.net/b/canthon-sp-6-spot.html&ei=D783UYaJGoaCrAHB5YCIDQ&psig=AFQjCNH4gRCTJZQ5qQ597RjtYqw9-LA0Hw&ust=1362694281596251http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=PLcynUuDNEFw6M&tbnid=-_1cMhF3C8e8fM:&ved=0CAUQjRw&url=http://www.flickriver.com/photos/botalex/tags/beetle/&ei=t743UYOzCY75qAGxzoDACw&psig=AFQjCNG5L_vHdtMeUTl9jdS2j9Z_Bl6RCg&ust=1362694184437334http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=yaWz_c8T73RbPM&tbnid=kjfBbsy2-B1m8M:&ved=0CAUQjRw&url=http://www.scielo.br/scielo.php?pid=S1519-566X2005000500003&script=sci_arttext&ei=Qb03Ue74DsaiqQGh6IDIDg&psig=AFQjCNH1dyhJn7v4UxM02lQfu3c9c0-bUA&ust=1362693798649516http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=y3a6BGRviriepM&tbnid=86aXMzBUOxNu0M:&ved=0CAUQjRw&url=http://www.amentsoc.org/publications/bulletin/articles/dung-beetles-of-ayrshire.html&ei=V8M3Ub7hOMiorAHVkYGoDA&psig=AFQjCNEHzdVZYEnEme1LNsQtwAPaV-mQIA&ust=1362695287694157http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=0RFFdHsjopNM1M&tbnid=JP8hicsZs7J83M:&ved=0CAUQjRw&url=http://sites.sinauer.com/ecology2e/ccc23.1.html&ei=D7g3Uc68PIaAqgGaroDoCQ&bvm=bv.43287494,d.aWM&psig=AFQjCNHliyFf9J4ehRGGwIhFwgdqqNFr4g&ust=1362692490670692http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=0RFFdHsjopNM1M&tbnid=JP8hicsZs7J83M:&ved=0CAUQjRw&url=http://sites.sinauer.com/ecology2e/ccc23.1.html&ei=D7g3Uc68PIaAqgGaroDoCQ&bvm=bv.43287494,d.aWM&psig=AFQjCNHliyFf9J4ehRGGwIhFwgdqqNFr4g&ust=1362692490670692


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Dominance and evenness: simple examples

D = Σ(ni/N)2

Species 1 33 97 60

Species 2 33 2 30

Species 3 34 1 10

=

(33/100)2

+(33/100)2

+(34/100)2

=0.33

=

(97/100)2

+(2/100)2

+(1/100)2

=0.94

=

(60/100)2

+(30/100)2

+(10/100)2

=0.46

Communities: how do they interact?

Step 3 of being a community ecologist:

Figure out how species in the community interact.

Limpkin

Florida panther

Key largo woodrat

Wood stork

Grey fox

Example 2: The Python Challenge

Burmese pythons (Python molurus bivitattus)

are invading Florida (pet releases and subsequent breeding)

Pythons can

reach 7 m, 90 kg

(a few near 200 kg!)

They constrict

(suffocate) their prey.

Native to SE Asia.

Background to the python problem

>1 million constrictors (9 species) imported

into US in last 30 years.

Some dumped into the wild when they grow too big

or owners tire of them.

First noticed wild in Florida in 1979;

noticeable problem from 2000 forward. Estimate:

>100,000


Florida’s 46 native snakes are SMALL;

pythons are BIG.

common kingsnake

~1 m.

Coralsnake

~75 cmcottonmouth

~1 m


The species in the Everglades evolved with small snakes, not big ones.

Boid (constrictor) snakes went extinct in Florida

20.6-16.3 million years ago. . .

Pythons are active both night and day.

NET EFFECT:

Pythons eat:

a) many species >45 bird species, many mammals, reptiles

b) big species deer, rabbit, opossum, sheep, heron

c) a lot of prey big body = big food intake

d) predators alligator, bobcat, fox, coyote

http://www.washingtonpost.com/national/health-science/pythons-kill-off-native-animals-in-everglades/2012/01/30/gIQAdawJdQ_gallery.htmlhttp://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=Bz85xe7nhB5VAM&tbnid=RZI5Pn9tYWhjqM:&ved=0CAUQjRw&url=http://weblogs.sun-sentinel.com/news/politics/dcblog/pythons/&ei=fs03UcSDHaStygGYlYCgBg&bvm=bv.43287494,d.aWc&psig=AFQjCNEHFaVVhKJHJCISFuL8LpE1r-JE1Q&ust=1362697934999372http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=lVQpvf66LC9vfM&tbnid=Tq5xuw_t2xHq6M:&ved=0CAUQjRw&url=http://www.currion.net/2012/11/09/cottonmouth/&ei=P8w3UdbsBsPmygHww4C4Bw&bvm=bv.43287494,d.aWc&psig=AFQjCNE48pMKNGOOUrKilYSC-I_cUJoGNA&ust=1362697653509096http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=Ogwnu3h1y56vXM&tbnid=KOKnf7kwZN5TcM:&ved=0CAUQjRw&url=http://onlyhdwallpapers.com/high-definition-wallpaper/greyfox-high-resolution-desktop-hd-wallpaper-233715/&ei=Qsk3UffUDMWuqAGZh4CwBA&psig=AFQjCNEwLNX0gpLdUhhQ5F9ihMWwkLWjvQ&ust=1362696882832244http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=ZtLkxCoT-mpTbM&tbnid=vRwmDWlVdmeFIM:&ved=0CAUQjRw&url=http://www.friedchickenandcoffee.com/2010/01/06/strapped-redneck/woodstork/&ei=78g3UdnPCsz-rAHZvICoAg&psig=AFQjCNHxbMX5iQZ7yFWLnBJIfuGGSeab9Q&ust=1362696770495844http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=_Aju2k7iQNkd6M&tbnid=1QilznCmuF-5PM:&ved=0CAUQjRw&url=http://www.allaboutbirds.org/guide/Limpkin/&ei=pcg3Ua64JcvMqQHK14C4CQ&psig=AFQjCNEEQFoXZC1vD2hCLWuslQzPokhf4w&ust=1362696713685772http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=7kRxzqVJAJE7UM&tbnid=ChadQ63uo2WY3M:&ved=0CAUQjRw&url=http://www.favorfloridakeys.com/Croc%20Lake%20NWR.htm&ei=WMg3UfmdC86yqAHm8YDICQ&psig=AFQjCNGLaBEl4ie8NXh1v8wqZV4JCC5uiA&ust=1362696637822045


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South Florida sampling locations in relation to python distribution.

Dorcas M E et al. PNAS 2012;109:2418-2422

©2012 by National Academy of Sciences

Python removals from Everglades and its environs from 1995 –2010.



Mammal roadkills from 1993 –1999, before pythons become common.



Mammal declines after python increases



Before pythons

After pythons

Many pythons

A few pythons

No pythons

Mammal declines after python increases: 2003-2011

87.5% decline in bobcats

99.3% decline in raccoons98.9% decline in opossums

94.1% decline in deer

No observations in 2011

cottontails

red fox (also grey fox)

Other invaders in Florida

Invasive species in Florida

cost >$0.5 billion per year

Argentine Tegu (~3 ft long):

eats sea turtle eggs

Nile monitor lizard

(~6 ft long):

kills pets

Cuban tree frog (~5”):

eats native frog species

lionfish:

eats native fish

http://localhost/var/www/apps/conversion/tmp/scratch_4//upload.wikimedia.org/wikipedia/commons/b/bf/Pterois_volitans_Manado-e_edit.jpghttp://en.wikipedia.org/wiki/File:Tupinambis-merianae-BA-Zoo.JPGhttp://floridadventure2012.files.wordpress.com/2011/09/nile_monitor.jpghttp://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=N4m1hhxzESGOXM&tbnid=OtR9vXfk9AbFiM:&ved=0CAUQjRw&url=http://animals.nationalgeographic.com/animals/mammals/red-fox/&ei=wNQ3UeD4AYrdrQGvxoGoCQ&psig=AFQjCNHBxq8yX-XAYIdSxjvtqDHZxYaefg&ust=1362699825421513http://localhost/var/www/apps/conversion/tmp/scratch_4//upload.wikimedia.org/wikipedia/commons/8/84/Sylvilagus_floridanus_14070.JPGhttp://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=HaCFhgyV8VJk4M&tbnid=3WCR977R2pIp1M:&ved=0CAUQjRw&url=http://animals.nationalgeographic.com/animals/mammals/white-tailed-deer/&ei=MdM3UZTlI4rKqQGGrIC4CQ&psig=AFQjCNHqsda0-uGAVtX_47kO3G79CZ7T1Q&ust=1362699434636576http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=M66kCEKBdhiiPM&tbnid=ZsJ-Oyc7UZhvWM:&ved=0CAUQjRw&url=http://true-wildlife.blogspot.com/2010/11/bobcat.html&ei=6dI3UYSJG4vPqAGOwYDQBA&psig=AFQjCNEc9g0iTZnktmqTnuzwVv7J_2i5PQ&ust=1362699361505005http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=tzoBgssAQ6s_EM&tbnid=9J-ZTzB_wmuexM:&ved=0CAUQjRw&url=http://www2.needham.k12.ma.us/eliot/technology/lessons/animals/opossum.htm&ei=dtI3UZX6DMW0qAGq6IDwCw&psig=AFQjCNG6_R9qxcyw4UT9USKK713ot7XymQ&ust=1362699244155781


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The human response 1: new law banning transport

of pythons across state lines

Jan 17, 2012, Federal ban on movement of 4 snake species

across state lines:

Burmese python

Anaconda

2 African pythons

• No new imports of these snakes as pets

• Cannot ship snakes across state lines

• Can’t even take your snake to the veterinarian across

state lines

The human response 2: the 2013 Python Challenge

Jan 12 – Feb 10, open hunt for pythons.

Cash rewards for most killed, largest killed.

1600 people from 38 states registered. . .

68 pythons killed

The human response 3: aftermath of the Python

Challenge

--No Python Challenge this year; need better trained

people to go after these animals

(volunteer Python Patrol?)

--All killed animals were necropsied. . .lots of

cotton rats as prey

The human response 3: aftermath of the Python

Challenge

A few weeks ago, the “Swamp Apes” were out

scouting for pythons again. . .and found a Nile Crocodile!

--Big & aggressive species

--Kill humans

--Kill big prey

Do some species have more impact

on their communities than others?Step 4 of being a community ecologist:

Figure out which species have large or small impactson presence / abundance of other species in the community.

python additions in Florida?

loss of wolves in most of US?

severe decline of Lyall’s mariposa lily

in S. Okanagan?

Keystone species: disproportionate impact

on community structure relative to their abundance

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=kiL2PloTanxVcM&tbnid=kjfkW9JJtRwQOM:&ved=0CAUQjRw&url=http://www.nps.gov/wica/naturescience/bison-wallow.htm&ei=Gdo3UY37EcPPqQHJhICYBw&psig=AFQjCNHuS4zLr7bpY2ac7TBSb9bYTg16hw&ust=1362701204980182http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=7Ed0mVDmDu_H1M&tbnid=Slgf4kQdxXHV1M:&ved=0CAUQjRw&url=http://www.bite.ca/bitedaily/2012/07/animal-of-the-week-the-beaver/&ei=hdk3UfzvIsK9qgGUl4HIDg&psig=AFQjCNGoR99_HwDFtHVrem4VwIn5sM7E-g&ust=1362701053762603http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=3xsf83RBXBvpsM&tbnid=l2tU16D1xmKkKM:&ved=0CAUQjRw&url=http://www.floridasportsman.com/2013/01/14/fwc-kicks-off-2013-python-challenge/&ei=C9c3UenDKYjmrAHrzYHgCw&psig=AFQjCNHWt42tQlt_2JOQGQmy6tk7dyiUrQ&ust=1362700350606736http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=bx7pP7B_jX26IM&tbnid=ulaCsSHPI_w71M:&ved=0CAUQjRw&url=http://www.voxxi.com/python-challenge-draws-about-800-hunters/&ei=yNY3Uci9LMHhrAGj6YHQCw&psig=AFQjCNHWt42tQlt_2JOQGQmy6tk7dyiUrQ&ust=1362700350606736


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Keystone species: creating habitat (ecosystem engineers) Keystone species: key trophic players

1871

1981

Succession: changes in communities through time

Succession - colonization and extinctions on a site by

species through time.

(Changes in richness, evenness, and dominance!)

Primary succession - succession following

disturbance that removes most biotic material from

the site.

Secondary succession - succession following a

disturbance that leaves soil, seeds, or organisms on

site.

Biological legacy - organisms, propagules, and

organic materials that survive disturbance.

Basic definitions of succession

How predictable (repeatable) is it?

after same kind of disturbance, will same

kind of community re-form by going through

same steps?

How idiosyncratic is it?

Will legacies, timing, and other site- and time-

specific details lead to different communities

after the same kind of disturbance?

Did disturbance fundamentally change the abiotic

conditions?

Key questions about succession Abiotic shift: boiling sulfuric acid kills trees

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=BT5mdSYAlk3SBM&tbnid=Cuqox5vJ46TbQM:&ved=0CAUQjRw&url=http://canadafurandfeathers.blogspot.com/2012/04/prairie-birds-and-prairie-dogs.html&ei=-9o3UcCQK4vuqQHXkICYCw&psig=AFQjCNGRxEYX3kZ_ajv4TjDjAPBlLHZLVg&ust=1362701416014037http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=pE87M9yyqfXrOM&tbnid=qapT66QIYYQ-zM:&ved=0CAUQjRw&url=http://www.panthera.org/photo-of-day?page=6&ei=vdo3UcnOKIbpqAGuz4CQCA&psig=AFQjCNEAdSym-uNyFhqdI4XUZxoCgZkjmA&ust=1362701367724305http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=Y0P902Oo92kLUM&tbnid=tuaFwbJDr58v-M:&ved=0CAUQjRw&url=http://zoo4950.wordpress.com/2011/03/13/butting-heads-with-the-beaver/&ei=e9o3Ua2YFsSVrAGRvoD4DA&psig=AFQjCNE_zlgaX48gHwYlr8fjRyntSpAk0A&ust=1362701302662072http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=7Ed0mVDmDu_H1M&tbnid=Slgf4kQdxXHV1M:&ved=0CAUQjRw&url=http://www.bite.ca/bitedaily/2012/07/animal-of-the-week-the-beaver/&ei=hdk3UfzvIsK9qgGUl4HIDg&psig=AFQjCNGoR99_HwDFtHVrem4VwIn5sM7E-g&ust=1362701053762603


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Tree kill without a huge abiotic shift: blow-down Glacial retreat—exposes mineral cobble

Primary succession: colonizing after glacial retreatPlant colonization in Glacier Bay, Alaska,

following glacial retreat

Secondary succession:

hardwood forest regeneration after fire

Key issues during PRIMARY succession

(predictable vs. idiosyncratic patterns)

1. Where do colonists come from?

2. What abiotic conditions do they find?

3. How do species’ interactions (facilitation, competition,

predation etc.) determine which species dominate?

4. What spatial patterns are evident in colonization?

http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=yihuH_ctj6_dtM&tbnid=N7odwdcshrV64M:&ved=0CAUQjRw&url=http://www.ethlife.ethz.ch/archive_articles/100607_Gletscher_su/index_EN&ei=h0k_UYfoI8izrQH-lIDQBQ&bvm=bv.43287494,d.aWM&psig=AFQjCNHmu308y5sIdO7-8yw02kQGX0weCw&ust=1363188472149111http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=t9E1DUb6MVH0dM&tbnid=yrSHXvSc67NTxM:&ved=0CAUQjRw&url=http://www.redwood.forestthreats.org/wind.htm&ei=1l4_UbzjLsW0qAHxi4HICg&bvm=bv.43287494,d.aWM&psig=AFQjCNFTdzMa6wY4S-8UtXpWgK7CQSpGGQ&ust=1363193926965563


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Key issues during SECONDARY succession

(predictable vs. idiosyncratic patterns)

1. Where do colonists come from? will previous dominant

continue as dominant?

2. What abiotic conditions do they find?

3. How do species’ interactions (facilitation, competition,

predation etc.) determine which species dominate?

4. What legacies are present and how important are they?

5. Will the same ‘climax’ communities come back

after going through the same stages?

Fire and volcanoes: key influences in Yellowstone

volcanoes: temperature, soils

(andesite, rhyolite)

fire: soils, seeds, biomass

Mature forests in Yellowstone: fuel for fires Regrowth of Lodgepole pines in Yellowstone after fire

Key question

--What drives density of stands regrowing after fire?

Major approach

--map areas of different sapling densities &

relate to soil, fire history, elevation

Turner et al. 2004. Ecosystems 7:751-775.

Predictors of post-fire regeneration:

elevation, soil, serotiny, and fire severity

Regeneration spans 6 orders of magnitude


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Colonists (and dominance/

evenness) affected by timing—

--of disturbance, and

--of species dispersal

“Succession” occurs at very different time scales

(remember, it’s just community shifts through time. . .)
http://www.google.ca/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=HB59MBKy70Wd2M&tbnid=8GhEmSljtlwqzM:&ved=0CAUQjRw&url=http://www.cosmographicresearch.org/prelim_glacial_maximum.htm&ei=X1M_Ue77C8HhrAHeh4CACg&bvm=bv.43287494,d.aWM&psig=AFQjCNHS1LZ_cqLY6M9YnXfmtkykW29kDw&ust=1363191003406523

Biol 201 Lecture 19 Communities_2

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Transcript of Biol 201 Lecture 19 Communities_2