Island Ecology

John J. Knapp
College of Agriculture and Crop Science
California Polytechnic State University
San Luis Obispo

Invasive species have been identified as the largest threat to biodiversity worldwide next to habitat destruction. The invasion has reached epic proportions around the globe, with the U.S. alone spending over one billion dollars for invasive plant management each year. Unfortunately, there are just too many invasive plants and too few resources to try to control them all. Controlling invasive plant species without a plan is like trying to win a football game by only playing defense; therefore it is vital to have a plan in place that identifies which invasive plant species pose the greatest threat to native ecosystems.

Having visited Catalina Island for many years and lived there for several, I wanted my Masters thesis research to benefit the place I call home. I will be producing a prioritized invasive plant management plan for the Catalina Island Conservancy, which will rank 63 invasive plant species found on the island. The formation of the plan includes:

• Identifying which non-native plant species are invasive.
• Conducting a literature review to gather information on biological characteristics and climatic preferences of each species.
• Surveying 233 major drainages, 200 ridgelines, 50 miles of coastline, over 200 miles of roads and all inhabited areas.
• Modeling the climactic preference of several plant species to predict their invasiveness.
• Subjecting each invasive species to a ranking index to produce a prioritized list of all invasive species island-wide.
• Ranking each watershed for management priority based on the rarity of the native habitat and extent of the invasive plant species infesting it.

It is my goal to produce an invasive plant management plan that will allow the Catalina Island Conservancy to make unbiased and ecologically sound decisions and utilize limited resources efficiently in order to protect and restore Catalina Island’s unique ecosystem.

Family / Scientific Name		Common Name
Pinaceae		Pine Family
†Pinus canariensis		Canary island pine
†Pinus halepensis		Aleppo pine
Aizoaceae		Fig Marigold Family
†Aptenia cordifolia		Baby sun rose
†Carpobrotus chilensis		Sea fig
†Carpobrotus edulis		Hottentot fig
†Mesembryanthemum crystallinum		Crystalline iceplant
Amaranthaceae		Amaranth Family
†Amaranthus albus		Tumbleweed
Anarcardiaceae		Sumac Family
†Schinus molle		Peruvian pepper-tree
†Schinus terebinthifolius		Brazilian pepper tree
Apiaceae		Carrot Family
†Conium maculatum		Poison hemlock
†Foeniculum vulgare		Fennel
Apocynaceae		Dogbane Family
†Vinca major		Periwinkle
Asteraceae		Sunflower Family
†Carduus pycnocephalus		Italian thistle
†Centaurea solstitialis		Yellow star thistle, Barnaby’s thistle
†Cirsium vulgare		Bull thistle
†Cynara cardunculua		Artichoke thistle
†Picris echioides		Bristly ox-tongue
†Senecio milkanioides		German ivy
†Silybum marianum		Milk thistle
‡Xanthium spinosum		Spiny cocklebur
Brassicaceae		Mustard Family
†Brassica nigra		Black mustard
†Brassica rapa		Yellow field mustard
†Cakile maritima		Sea rocket
†Raphanus raphanistrum		Jointed charlock
†Raphanus sativus		Wild radish
†Rorippa nasturtium-aquaticum		Water cress
Chenopodiaceae		Goosefoot Family
†Atriplex semibaccata		Australian saltbush
†Salsola tragus		Russian thistle, Tumbleweed
Convolvulaceae		Morning Glory Family
†Convolvulus arvensis		Bindweed
Euphorbiaceae		Spurge Family
†Ricinus communis		Castor bean
Fabaceae		Pea Family
†Acacia decurrens		Green wattle
†Acacia melanoxylon		Blackwood acacia
†Caesalpinia spinosa		Tara
†Genista linifolia		Dyer’s greenwold
†Genista monspessulana		French broom
†Spartium junceum		Spanish broom
†Vicia villosa varia		Hairy vetch
Geraniaceae		Geranium Family
†Pelargonium x hortorum		Garden geranium
Lamiaceae		Mint Family
†Marrubium vulgare		orehound
Moraceae		Mulberry Family
†Ficus carica		Common fig
Myrtaceae		Myrtle Family
†Eucalyptus globulus		Tasmanian blue gum
†Eucalyptus spp.		Gum trees
Oxalidaceae		Oxalis Family
†Oxalis pes-caprae		Bermuda buttercup
Pittosporaceae		Pittosporum Family
†Pittosporum undulatum		Mock orange, Victorian box
Platanaceae		Sycamore Family
†Platanus acerifolia	London planetree
‡Platanus racemosa	Western sycamore, California sycamore
Rosaceae	Rose Family
†Cotoneaster sp.	Cotoneaster
†Rubus discolor	Himalayan blackberry
Simaroubaceae
†Ailanthus altissma	Tree-of-heaven
Solanaceae	Nightshade Family
†Nicotiana glauca	Tree tobacco
†Solanum elaeagnifolium	White horse nettle, Silver-leaved horse nettle
Tamaricaceae	Tamarisk Family
†Tamarix ramosissima	Salt cedar, Tamarisk
Tropaeolaceae	Nasturtium Family
†Tropaeolum majus	Garden nasturtium
Arecaceae	Palm Family
†Washingtonia robusta	Fan palm
†Washingtonia filifera	Palm
†Phoenix canariensis	Canary island date palm
†Phoenix spp.	Palm
Liliaceae	Lily Family
†Asparagus asparagoides	Asparagus
Poaceae	Grass Family
†Arund donax	Giant reed
†Cortaderia selloana	Pampas grass
†Cynodon dactylon	Bermuda grass
†Dactylis glomerata	Orchard grass
†Digitaria sanguinalis	Crabgrass
†Ehrharta calycina	Veldt grass
†Ehrharta erecta	Ehrharta
†Pennisetum clandestinum	Kikuyu grass
†Phalaris aquatica	Harding grass
†Piptatherum miliaceum	Smilo grass
Potamogetonaceae	Pondweed Family
†Potamogeton crispus	Pondweed