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Biological invasion (生物学的侵入)

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

[ Biological invasion | Invasive alien species ]

(sensu lato) human-assisted introductions of species that expands natural range

Assembly rules + Alien plants

1. How many species?
2. Which species?
3. What relative abundance?

Theoretical background
Competitive exclusion
Niche models
Spatial heterogeneity
Temporal variation

Different kinds of years
The superior competitor in common years must be the inferior competitor in rare years
Storage effect to survive runs of bad years
Difference in regeneration niche

Non-equilibrium models Table. Classification of species that are introduced from the outside
  • Native species: a species that is a part of the original ecosystem of the area in question
  • Exotic species (帰化種): a species that is not native to the region (country) in which it is found with and without human activity (→ weed)
  • Introduced species (導入種): a species introduced from another geographical region through human activity
    * the plant (or its propagule) has been transported by humans across a major geographical barrier
  • Naturalized species (帰化種): an introduced species that has become adapted to a new region.
    * the plant starts when abiotic and biotic barriers to survival are surmounted and when various barriers to regular reproduction are overcome
  • Invasive species (侵入種): an exotic species that becomes a component of native ecosystems in the region
    Example: Larix kaempferi on Mount Koma, northern Japan
    * the plant further requires that introduced plants produce reproductive offspring in areas distant from sites of introduction (> ca 100 m over < ca 50 years for taxa spreading by seeds and other propagules; > ca 6 m/3 years for taxa spreading by roots, rhizomes, stolons or creeping stems)
*: defined by Richardson et al. (2000) for plants
Invasions of exotic species into new geographical areas sometimes occur naturally and without human agency. However, human actions have increased this trickle to a flood ... Many introduced species are assimilated into communities without much obvious effect (Townsend et al. 2000).

Invasive alien species (IAS) (侵略的外来種)

Biological meaning
Non-native species invades an ecosystem and leads environmental harm, in particular, decreasing biodiversity. The causes of invasion are mostly originated from human disturbances, such as climate change, pollution, and habitat loss.
Socio-economical meaning
In addition to bilogical meaning, IAS adversely affects economy, e.g., agriculture, forestry and fisheries, or human health. The effects of IAS is often evaluated by the cost.

Hokkaido Blue List (北海道ブルーリスト)

established in 2004 and revised in 2010
Providing basic information on the status of alien species in Hokkaido (↔ red list)

Exotic plant (帰化植物)

= exotic plant, new-comer, stranger, alien, anthropophyte, etc.
1912 Thellung
  • Apophyte: native plants growing in disturbed land, such as in an abandoned field
  • Neophyte: plants that do not originally occur in an area but were brought there by humans after 1492 in the case of Europe
  • Ephemerophyte: non-natives (mostly neophytes) that occur only sporadically in an area and have not established permanent populations
1960 Sukopp
  • membership naturalization (adoption) - ecesis resistance
  • replacement naturalization (displacement) - ecological homeostasis

[ Washington State, USA ] weed control | references ]

Weed (雑草)

An unwanted wild plant, especially one which prevents crops or garden flowers from growing property
⇓ The simplest definition I think is: "any plant that disturbs human life."
This means that the plant is weedy in some regions and is non-weedy in the other regions. For example, Pteridium aquilinum (L.) Kuhn (Bracken Fern) is a wild vegetable for Japanese and thus is not weed, but is defenitely a weed for tropical regions, in particular, in post-fire areas.
Any of several kinds of plant which appear to die at the end of the growing season but grow agian the next year, especially one which is used to make medicine or to make food taste stronger

→ herbaceous species, herbage

Weeds in Japan, in particular, Hokkaido
Aegopodium podagraria L. (Bishop's goutweed), perennial
Amaranthus retroflexus L. (Redroot pigweed), annual
Bidens frondosa L. (Devil's beggartick), annual
Epilobium angustifolium L. (Fireweed), perennial
Galinsoga ciliata (Raf.) Blake (Shaggy soldier), annual
Hypochaeris radicata L. (Hairy Catsear), perennial
Linaria vulgaris Miller (Common Toadflax), perennial
Matricaria matricarioides (Less.) Porter (Pineapple Weed), annual
Plantago lanceolata L. (Narrowleaf plantain), perennial
Polygonum arenastrum Jord. ex Boreau (Oval-leaf knotweed), annual
Polygonum sachalinense Fr. Schm. (Giant knotweed), perennial
Rumex acetosella L. (Sheep Sorrel), annual/perennial
Rumex obtusifolius L. (Bitter-Dock), perennial
Setaria pumila (Poir.) Roemer et Schultes (Bitter-Dock), annual
Spergularia rubra (L.) C. Presl (Red sandspurrey), annual

Weed control (雑草防除)

Conparisons of weed control techniques

Control typeDirect controlHabitat manipulationOver-disturbancesBiological controlHerbicides (+Pesticides)
CostExtremely HighLowLowCase-by-caseLow
MeritLow-costLow-costNot adequate for mass outbreakInstant remedy
DemeritHigh-cost, Waste timeLong-termLong-termPollution, Plant resistance, Herbivore may re-occur, Simple ecosystem
  • Habitat manipulation: smother crops, fertilizer, limit disturbances
  • Over-disturbances → plowing, etc. → intermediate disturbance hypothesis
  • Herbicides + Pesticides: Demerit = High cost, Pollution. Plants often can get resistance to herbicides

[Cascades: forest zones, plant species, wetlands]

Weed species in Washington State

Trees/shrubsAlnus rubra (red alder)Clear cuts, roads
Cytissus scoparius (Scotch broom)Pastures, roadsHedera helix (English ivy)Urban woodlots
Hypericum perforatum (Klamath weed)Pastures, roads, clear cutsIlex aquifolium (English holly)Urban woodlots
Lythrum salicaria (purple loosestrife)WetlandsRubus discolor (Himalayan blackberry)Pastures, meadows, roads
Solanum dulcamara (bittersweet nightshade)Moist, shady sitesSorbus acuparia (rowan, mountain ash)Urban woodlots
Ulex europaeus (gorse)Pastures, dry hillsidesGraminoids
Agropyron repens (quackgrass)Moist pasturesBromus tectorum (cheat grass)Dry pastures, steppe
Dactylis glomerata (orchard grass)Moist, rich pasturesHolcus mollis (creeping velvet grass) Lawns
Juncus spp. (rushes)Wetlands, wet pasturesLolium perenne (perennial ryegrass)Pastures and meadows
Phalaris arundinacea (read canaarygrass)WetlandsPhleum pratense (timothy)Pastures, roads
Poa spp. (bluegrasses)Lawns, pastruesHerbaceous perennials
Achillea millefolium (yarrow)LawnsArctium spp. (burdock)Roads, waste places
Bellis perennis (English daisy)Lawns and trampled areasCentaurea diffusa (diffuse knapweed)Vacant lots, roads, pastures
Chrysanthemum leucanthemum (ox-eyed daisy)Roads, clearcutsCichorium intybus (chicory)Roads, pastures, meadows
Cirsium arvense (Canada thistle)Pastrues, roadsConium maculatum (poison hemlock)Waste places
Convolvulus spp. (bindweeds) Plantings, crops, roads Daucus carota (wild carrot) Meadows, waste places
Digitalis purpurea (foxglove) Roads Epilobium angustifolium (fireweed) Clear cuts, waste places
Equisetum arvense (horsetail) Moist waste places Glechoma hederaceae (ground ivy) Waste places
Hypochaeris glabra (false dandelion) Lawns, waste places Plantago spp. (plantains) Lawns, waste places
Polygonum cuspidatum (Japanese knotweed) Ornamentals, roads Pteridium aquilinum (bracken fern) Meadows, clear cuts
Ranunculus repens (creeping buttercup) Moist lawns, waste places Rumex acetosella (sour dock) Waste places
Rumex crispus (curly dock) Waste places Senecio jacobaea (tansy ragwort) Pastures
Sonchus arvensis (perennial sow thistle) Pastures, waste places Tanacetum vulgare (common tansey) Pastures, waste places
Taraxacum officinale (dandelion) Lawns, waste places Trifolium spp. (clover) Pastures, roads, lawns
Urtica dioica (stinging nettle) Rich farm sites, forests Verbascum thapsus (mullein) Arid roadsides
Annuals Anthemis cotula (mayweed) Trampled sites
Brassica campestris (field mustard) Mesic pastures Capsella bursa-pastoris (shepherd's purse) Waste places
Chenopodium album (lamb's quarter) Rich garden soil Erodium cicutarium (filare) Drier meadows, trampled sites
Eschscholtzia californica (California poppy) Dry, rocky urban sites Geranium molle (dove's foot geranium) Lawns, waste places
Lamium spp. (dead nettle) Meadows Matricaria matricarioides (pineapple weed) Trampled sites
Medicago lupulina (black medic) Lawns Polygonum persicaria (smartweed) Pastrues, meadows, sidewalks
Senecio vulgaris (groundsel) Gardens, roadsides Stellaria media (chickweed) Gardens
Table 1. Tolerance ranges of common weeds in Washington. Moisture: X = xeric; D = dry; E = mesic; O = moist; W = wet; H=hydrid. Nutrient: P = poor fertility; L = low fertility; A = average fertility; R = rich soil; E = excessive nitrogen. Soil pH: S = strong acid; M = moderately acidic; W = weakly acidic; N = neutral.
Species name (common name)MoistureNutrientSoil pHComments
Achillea millefolium (yarrow) xxx xxx xxx Grazed
Agropyron repens (quackgrass) xx xxx xx Disturbed, grazed
Aira carophyllea (silver hairgrass) xx xx xx Rocky, overgrazed
Alnus rubra (red alder) xxxx xx xxxx Native; floodplains & clearcuts
Amaranthus retroflexus (redroot pigweed) xxx xx xxxx
Ambrosia artemisifolia (ragweed) xxx xxx xxx
Anaphalis margaritacea (pearly everlasting) xx xx xx Native
Anthemis cotula (mayweed) xx xxx x
Arctium lappa (burdock) xxx xx
Arctium minus (common burdock) xxx xx
Artemisia vulgaris (mugwort) xx xx xxxx Greatly distributed; overgrazed
Asclepias fasicularis (narrowleaf milkweed) xx
Avena fatua (wild oats) xx xx xxx
Bellis perennis (English daisy) xx Lawns and trampled areas
Bidens frondosa (beggar ticks) xx xx
Brassica campestris (wild mustard) xxx xx Early succession in fields
Bromus tectorum (cheat grass) xx xxx Sandy, gravely soil; overgrazed
Capsella bursa-pastoris (shepherd's purse) xxx xx
Cardamine oligosperma (little bittercress) xx xxx
Centaurea cyanus (bachelor button) xx Meadows
Cerastium arvense (field chickweed) xx x xx
Cerastium viscosum (sticky mouse-ear chickweed) x xx x
Cerastium vulgatum (mouse-ear chickweed) xx xx
Chenopodium album (lambsquarter) xxx x
Chrysanthemum leucanthemum (ox-eyed daisy) xx xx xxxx
Cichorium intybus (chicory) xx x x
Cicuta douglasii (water hemlock) xx xx
Cirsium arvense (Canada thistle) xxx xx xxxx Overgrazed
Cirsium vulgare (bull thistle) xxx xx xxxx
Conium maculatum (poison hemlock) xx xxx Poisonous
Conringia orientalis (haresear mustard) x xxx Seeds poisonous
Convolvulus arvense (field bindweed) xxx xx
Convolvulus sepium (hedge bindweed) xx
Conyza canadensis (horseweed) xx xx Overgrazed
Crepis capillaris (smooth hawksbeard) xx Rocky soil
Cuscuta spp. (dodder) Parasitic
Cynoglossum officinale (hounds tongue) xxx
Cynosurus echinatus (hedgehog dogtail) xx Rocky soil
Cyperus esculentus (yellow nutgrass) xx xx Poor drainage
Cytissus scoparius (Scotch broom) xxx xx Nitrogen fixing
Dactylis glomerata (orchard grass) xx x xx Meadows
Datura stramonium (Jimsonweed) x xx Poisonous
Daucus carota (wild carrot) xx x xx
Descurania pinnata (tansey mustard) xx
Digitalis purpurea (foxglove) x xx Poisonous seeds
Digitaria sanguinalis (crabgrass) xx
Dipsaccus sylvestris (teasel) xx Ditches
Echinochola crus-galli (barnyard grass) xxx x
Elymus caput-medsae (Medusa head) xxx
Epilobium angustifolium (fireweed) xxx xx After fires; native
Epilobium minutum (willowweed) xx xxx
Equisetum arvense (field horsetail) xxx xxx xx
Erodium cicutarium (filare) xx xx xx Rocky, open fields
Eschscholtzia californica (California poppy) xx Rocky sites
Euphorbia peplus (petty spurge) xx xx Shaded
Galium aparine (bedstraw) xx xx Shaded
Geranium carolinianum (Carolina geranium) x
Geranium molle (dove's foot geranium) xx xxx Open
Geranium robertianum (Robert's geranium) xx xxx
Geranium pusillum (small geranium) x xx
Glechoma hederaceae (ground ivy) xx x Woods, moist lawns
Helianthus annus (sunflower) xx xxx
Hedera helix (English ivy) xx xxx
Holcus lanatus (velvet grass) xxx xx
Holcus mollis (creeping velvet grass) xx xx
Hordeum jubatum (foxtail barley) xx xxx Tolerates saline soil
Hyoscyamus niger (black henbane) xx xx
Hypericum perforatum (Klamath weed) xx xx Poisonous
Hypochaeris glabra (false dandelion) xx x
Hypochaeris radicata (false dandelion) xx x x Lawns
Ilex aquifolium (English holly) xx xx
Iva axillaris (poverty weed) x
Juncus effusus (soft rush) xx x x
Juncus tennuis (slender rush) xx
Lactuca serriola (prickly lettuce) xx xx
Lamium amplexicaule (henbit) xx xx
Lamium purpurea (dead nettle) xxx xx xx
Lapsana communis (nipplewort) xx
Lepidium virginicum (Virginia pepperweed) xx
Linaria vulgaris (yellow toadflax) xx xx
Lolium perenne (perennial ryegrass) xx xx Pastures
Lotus corniculatus (bird's foot tre-foil) xx xx Lawns
Lychnis alba (white cockle) xx
Lysimachia nummularia (moneywort) xx xxx xxx
Lythrum salicaria (purple loosestrife) xx xx Marshes, lakes
Malva neglecta (cheeseplant) xx
Matricaria matricarioides (pineapple weed) xx x Trampling
Melilotus alba (white sweet colver) xx xx Pastures
Medicago lupulina (black medic) xx xx Lawns
Mentha arvensis (field mint) xx
Mollugo verticillata (carpetweed) xx xx
Oxalis stricta (yellow wood sorrel) xx
Paspalum distichum (knotgrass)
Phalaris arundinacea (reedgrass) xx xx xx Ditches
Phleum pratense (timothy) xx x Pastures
Phragmites communis (reedgrass) x xxx x Ditches, lakes
Plantago lanceolara (English plantain) xxxx xxxx xxx
Plantago major (broad leaf plantain) xx xxxx xxxx Trampling
Poa annua (annual bluegrass) xx xx xxxx Lawns
Poa compressa (Canada bluegrass) xx xx xx
Poa pratense (Kentucky bluegrass) xxxx xxx xxxx Lawns, meadows
Poa trivialis (roughstalk bluegrass) xx xx
Polygonum aviculare (knotweed) x xx Trampling
Polygonum convolvulus (black bindweed) xxxx xx xx
Polygonum cuspidatum (Japanese knotweed) xx xxx
Polygonum persicaria (smartweed) xx xx
Polypogon monspeliensis (rabbit foot grass) xxxxx xx Tolerates brackish water
Portulaca oleracea (purslane) xxx xx
Prunella vulgaris (heal-all) xxxx xxx xxxx
Pteridium aquilinum (bracken fern) xxx xx xx Native; carcinogenic
Ranunculus acris (tall field buttercup) xx xxx xxxx Heavy soils
Ranunculus repens (creeping buttercup) xx xxxx xxxx Wet lawns
Rhus diversiloba (poison oak) xx Native; causes skin irritation
Rosa canina (dog rose) xx Hegergrows
Rubus discolor (Himalayan blackberry) xxx xx
Rubus laciniatus (evergreen blackberry) xxx xxx
Rumex acetocella (sour dock) xx xx x
Rumex crispus (curly dock) xx xx xxxx
Saponaria officinalis (saopwrot; bouncing bet) xxx
Senecio jacobaea (tansy ragwort) xxx xx x Poisonous
Senecio sylvestris (woodland groundsel) xx
Senecio vulgaris (groundsel) xx
Setaria viridis (green foxtail) xxx x
Silene cucubalis (bladder campion) xx xx
Sisymbrium officinale (hege mustard) xx xx
Solanum dulcamara (bittersweet nightshade) xx Poisonous
Solanum nigrum (black nightshade) xx xx Poisonous
Solidago canadnesis (goldenrod) xx xx
Sonchus arvensis (perennial sow thistle) xxx xxx
Sonchus asper (prickley thistle) xxx xxx
Sonchus oleraceus (annual sowthistle) xx xxx
Sorbus acuparia (mountain ash) xx xx
Spergula arvensis (corn spurry) xxx xx
Stellaria media (chickweed) xx xx
Tanacetum vulgare (tansey) xx
Taraxacum officinale (dandelion) xxxx xx xxxx Lawns
Thlaspi arvense (pennycress) xxx x
Tragopogon dubius (goatsbeard) xx xxx
Trifolium dubium (small hop clover) x x x Nitrogen fixer
Trifolium pratense (red clover) xxxx xx xxxx Nitrogen fixer
Trifolium procumbens (low hop clover) xxx xxx xxx Nitrogen fixer
Trifolium repens (white clover) xxxx xxx xxxx Nitrogen fixer
Triglochin maritimum (seaside arrowgrass) xx xxx Salt tolerant
Typha latifolia (cattail) x xx Wetlands
Urtica dioica (stinging nettle) xxx xx xxxx
Ulex europaeus (gorse) xx Overgrazed; nitrogen fixer
Verbascum blattaria (moth mullein) xx xx
Verbascum thapsus (mullein) xxx xx xx
Veronica peregrina (purslane speedwell) xx
Veronica seryphylla (winter speedwell) xx xx
Vicia sativa (vetch) xx xx Nitrogen fixer
Vinca major (periwinkle) xx xx Moist, shaded slopes

[ biomagnification ]

Agrichemicals (農薬)

Agrichemical or agrochemical = agricultural chemical
  • pesticides including insecticides
  • herbicides
  • fungicides and nematicides
+ synthetic fertilizers, hormones and other chemical growth agents


4500BP Sumerians, sulfur used for insecticides
3200BP China, mercery and arsenic compounds

used for controling body lice

3000BP Rome, the advent of agrichemicals?

Ex. the Roman era: a record of soaking barley seeds into wine and sprinkled plant ash and sulfur on crop fields (expected magical effect?)

sulfur (硫黄): still used as agrichemicals in the present (probably the world's first agrichemicals)

1941 France, BHC
1944 Germany, parathion (パラチオン)
1944 USA, dieldrin (ディルドリン)

→ all showing highly effective insecticidal effects → spreading around the world, mainly from developed countries