Biolo logic ical C l Control l of Weeds: s: Reconst nstit - - PowerPoint PPT Presentation

Biolo logic ical C l Control l of Weeds: s: Reconst nstit itut uting ing G God’s s Plan

• F. A

Allen Dr Dray Jr., Ec Ecologi gist U.S. D . Dept. of

• f A

Agriculture Agricultural R Research Se Service Invas asive Pl Plant t Res esear arch L Lab Fort L t Laude derdal dale, F FL

(3) Abraham was called away…

Humans migrate…

Credits: (1) Falco (2015) https://pixabay.com/en/church-door-portal-metal-input-753812/ (2) Smith (2002) https://www.theswordbearer.org/images/wallpapers/W017_ark_std.jpg (3) Molnar (1850) https://commons.wikimedia.org/wiki/File:Molnár_Ábrahám_kiköltözése_1850.jpg (4) Rohl (2015) https://www.flickr.com/photos/99714170@N03/16570793350/

(2) Noah floated away… (1) Cain ran away… (4) Moses walked away…

Humans migrate…

we began millennia ago and are still doing so today

Credits: (1) Wade (2000) The Human Family Tree: 10 Adams and 18 Eves, https://archive.nytimes.com/www.nytimes.com/library/national/science/050200sci-genetics-evolution.html (2) Metrocosm.com (2016) https://www.weforum.org/agenda/2016/07/the-worlds-immigration-in-one-map/

(2) International migration 2010-2015 (1) Human genetic history

Humans migrate…

bringing other organisms along…intentionally or otherwise

Credits: (1) F. & K. Starr (2009) http://www.starrenvironmental.com/images/image/?q=24966795025 (2) Horikoshi (2016) http://ediblehi.com/poi/ (3) Wee (2017) http://www.besgroup.org/2017/01/13/to-cull-or-not-to-cull-the-red-junglefowl/

e.g., Polynesians settling Hawai’i (3) Gallus gallus (red junglefowl) (2) Colocasia esculenta (taro) (1) Dioscorea bulbifera (air potato)

Humans migrate…

bringing other organisms along…intentionally or otherwise

Credits: (1) Roullier et al (2013) Historical collections reveal patterns of diffusion of sweet potato in Oceania obscured by modern plant movements and recombination. Proceedings of the National Academy of Sciences 110(6): 2205-2210. (2) Southern Exposure Seed Exchange (2018) http://www.southernexposure.com/images/sweet-potatoes-freshly-dug.jpg

(2) Ipomoea batata (sweet potato) e.g., Polynesians settling Hawai’i (1) Sweet potato invasions of Oceania

Human movement of organisms…

Global homogenization of biotas

• Baiser et al (2012) showed that faunas

and floras have generally become more similar over time

• Some ecologists have begun calling

the post-Columbian portion of the Holocene Epoch… the Homogenocene

• Geologists have a formal process

underway to rename part or all of the Holocene…the Anthropocene

Credits: (1) Baiser et al (2012) Pattern and process of biotic homogenization in the New Pangea. Proceedings of the Royal Society B 279: 4772-4777. (2) Olden (2013) Biotic homogenization, http://depts.washington.edu/oldenlab/biotic-homogenization/

(2) Biotic homogenization

Exotic species

Organisms occurring in habitats where they did not

• ccur in pre-Columbian times

Credits: (1) Keys (2013) http://illinoisisam.blogspot.com/2013/06/the-hunt-for-invasive-species-slogans.html

Credits: (1)Anonymous (2018) Goldflame honeysuckle, https://www.jacksonandperkins.com/gold-flame-honeysuckle/p/25952/

Exotic species … can be benign

• Many, perhaps even most,

horticultural plants grow

• nly where planted

(1) Gold flame honeysuckle (Lonicera x heckrottii)

Credits: (1) Schlaepfer et al (2011) The potential conservation value of non-native species. Conservation Biology 25(3): 428-437. (2) Hung et al (2018) The worldwide importance of honey bees as pollinators in natural habitats. Proceedings of the Royal Society B 285:

Exotic species … can be beneficial

• European honey

bees (Apis mellifera) pollinate many native plants (Schlaepfer et al 2011) (2) Honey bees pollinating native CA cactus

Exotic organisms … alter ecosystems intentionally

Credits: (1) US-FWS (2010) Land Protection Plan: Flint Hills Legacy Conservation Area, Kansas. https://www.fws.gov/mountain- prairie/refuges/lpp_PDFs/flh_lpp_final_all.pdf (2) Prepelka (2008) Tallgrass Prairie National Preserve, http://www.scenicusa.net/101908.html (3) Andorka (2018) https://pv-magazine-usa.com/2018/02/28/bp-backs-20-mw-solar-project-in-kansas/

(1) Tallgrass prairies (3) Former tallgrass prairie (2) Tallgrass prairie remnant

Exotic organisms … alter ecosystems unintentionally

Credits: (1) Flynn (2014) http://orchidswamp.org/the-park/natural-history/06-cypress-dome-on-copeland-prairie/ (2) USDA (2004) Melaleuca replacing cypress dome.

(2) Melaleuca quinquenervia (cajeput) dome (1)Taxodium ascendens (pond cypress) dome

Exotic organisms … alter ecosystems unintentionally

Credits: (1) UF-IFAS (2018) Plant management in Florida waters – an integrated approach. https://plants.ifas.ufl.edu/manage/why-manage-plants/native-plants/ (2) FLEPPC (2017) Florida Exotic Pest Plant Council’s 2017 List of Invasive Plant Species, http://www.fleppc.org/list/list.htm

Some exotic biota become destructive

• >4200 species of plants outside of cultivation in

Florida (UF-IFAS 2018)

• ~3000 are native, the rest introduced
• 165 are considered invasive FLEPPC (2017)
• Half of these are Category I species

“Invasive exotics that are altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives.”

Credits: (1) Rosenzweig (2001) The four questions: what does the introduction of exotic species do to diversity? Evolutionary Ecology Research 3(3): 361-367. (2) Dray (2012) D. bulbifera infestation at Snyder Park, Fort Lauderdale, FL. (3) Hunter (2008) If It’s Green, It’s Good? Invasive Species in our Backyards. https://vimeo.com/10262935

• Rosenzweig (2001) “The words

‘good’ and ‘bad’ constitute value judgements and so lie beyond the bounds of science...”

• Lay public: “If its green, its good.”

(Hunter 2008)

Exotic organisms … alter ecosystems

These outcomes are considered undesirable by most ecologists, including those of us working in biological

• control. However, this judgement is not without

controversy…

(2) Dioscorea bulbifera (air potato)

Credits: (1) NIV Cultural Backgrounds Study Bible (2016) Genesis 1: 9, 12, 18, 25, and 31 (2) Leopold (1949) A Sand County Almanac

Exotic organisms … alter ecosystems

• Of course, from a Christian environmentalist’s perspective

“And God saw that it was good.” (1) provides a correct and necessary structural framework within which to make such moral (ethical) judgements.

• Thus, loss of species…or destruction of habitats is “wrong” or

“bad” because it uncouples biotic communities and relationships that God declared “good”.

• "A thing is right when it tends to preserve the integrity,

stability, and beauty of the biotic community. It is wrong when it tends otherwise.” (Leopold 1949)

Biological control - defined

Biological control (biocontrol) is the science of re-associating natural enemies with their hosts in regions where neither the host nor the enemy naturally occurs. The goal is to produce enough stress to the host that it no longer causes problems in its non-native range.

Biological control - defined

The goal of biological control is not eradication of the weed. Most biological control projects do not result in “complete” control (no other control measures needed) but rather they result in “substantial” control in which other methods are needed to reduce the weed to acceptable levels albeit with less effort (Hoffman, 1995).

Credits: (1) Hoffman (1995) Biological control of weeds: the way forward, a South African perspective. In: Weeds in a Changing

• World. British Crop Protection Council Symposium Proceedings no. 64 (ed J. K. Waage) pp. 77–98. The British Crop

Protection Council, Farnham

Eliminate Eradicate

Biological control – the process

• Foreign surveys (find the critters)
• Quarantine studies (make sure they’re safe)
• Release & establishment (get them into the field)
• Long-term monitoring (determine effectiveness)
• Redistribution (move them around if necessary)
• Technology transfer (help others use the critters)

Credits: (1) USACE (1998) https://el.erdc.dren.mil/apis/Biocontrol/ProcessMain.aspx

Biological control – the process

Biological control - safety

Biological control - safety

The Centrifugal Method (Phylogenetic)

• Target species: Dioscorea bulbifera
• U.S. congeners: Dioscorea villosa & D. floridana
• Caribbean/MesoAmerican congeners: D. (R.) cordata, D. trifida
• Exotic congeners in U.S.: D. polystachya
• Congeners that are T & E: none
• Economically important congeners: D. alata & D. cayennensis
• Other families within order (Dioscoreales): Burmanniaceae
• Closely related orders: Pandanales (eg, Croomia pauciflora)
• Representatives from superorder Lilianae: eg, Crinum americanum
• Economically important non-Lilianae: eg, Solanum tuberosum
• Ecologically important habitat associates: Smilax laurifolia (FL T&E)
• Species fed upon by proposed bioagent congeners (eg, Lilium sp)

Biological control - safety

Lilioceris egena 82 spp, 46 families, 25 orders

Biological control - safety

Credits: (1) Pemberton (2000) Predictable risk to native plants in weed biocontrol. Oecologia 125: 489-494. (2) Louda et al (2003) Nontarget effects – the Achilles’ heel of biological control? Annual Review of Entomology 48: 365-396.

153 agents released against 53 weeds in US & Hawaii

• Of these, 15 also attack non-targets (n=40 plants)
• Physiological host range trials predicted all but 1 of these

attacks

• The bug Teleonemia scrupulosa introduced into Hawaii in

1902 against Lanatana camara without testing.

• Most famous case is Rhinocyllus conicus, introduced in

1969 against exotic thistles, attacks 22 of 90 native Cirsium as well. This insect was known to attack multiple species of Cirsium, Carduus, Onopordum, & Silybum in Europe, so attacks of natives was predictable.

Biological control - efficacy

Credits: (1) Julien & Griffiths (1998) Biological Control of Weeds: A World Catalog of Agents and Their Target Weeds, 4th Ed.

Worldwide: 368 agents vs 135 target weeds, 1172 attempts Established Yes No Unknown Effective Yes 319 n/a n/a No 192 n/a n/a Unknown 193 n/a n/a Totals 704 347 121

• 67 % established

persistent populations

• 62 % cause population

level effects

• For many,

establishment & efficacy unknown

Biological control - efficacy

Is it possible to evaluate efficacy prior to release? Doing so requires recreating habitats like these. (1) Bulang Mtn, Yunnan, China (2) Green Stone Forest, Yunnan, China

Biological control - efficacy

Credits: (1) Crawley (1983) Herbivory: The Dynamics of Animal-Plant Interactions

“The principal effect of herbivores on plant species richness acts not through the animals eating the plants to extinction, but through their feeding modifying the competitive abilities of one plant species with another” (Crawley 1983) Plant-insect interactions are quite complex, and …

Biological control - success

Success, like beauty, is often in the eye of the beholder.

Credits: (1) Hogervorst (2005) https://commons.wikimedia.org/wiki/File:MuscovyDuck.jpg

(1) Cairina moschata (muskovy ducks)

Biological control – success Melaleuca quinquenervia

Strat ategy

El Eliminate te s sta tands ds Pr Prevent R t Regen enerati tion Her erbici cida dal Co Contr trol & Mechanical R Removal Biologi gical al Cont

• ntrol

Credits: (1) Laroche (1994, 1999) Melaleuca Management Plan for South Florida

• Melaleuca stands removed from public lands
• Biological control implemented

 Seed production reduced 98%  Stand densities reduced ≥85%  Sapling growth strongly curtailed  Coppicing reduced  Seedling survival reduced by ≥60%  Reduced canopy, increased light penetration  Increasing biodiversity

• Melaleuca is now much less invasive

Conclusion: All goals have been achieved so the project is a “success” despite the continued existence

• f dense infestations.

Biological control – success Melaleuca quinquenervia

Biological control of invasive weeds

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