, Volume 166, Issue 4, pp 935–947 | Cite as

Relative effects of environment and direct species interactions on the population growth rate of an exotic ascidian

Population ecology - Original Paper


The success of exotic species can be influenced by both the abiotic environment and species interactions. Many studies have demonstrated significant effects of either type of factor on aspects of exotic success, but few have considered their relative effects on population growth rate, a more holistic measure of success. To quantify the relative effects of environment and direct competition on an exotic ascidian, Botrylloides violaceus, I manipulated direct contact interactions at four sites with different abiotic environments and tracked individual colonies over 3 years. I tested site and contact treatment effects on survival, growth and fecundity, and then conducted a life table response experiment on a periodic, size-structured population matrix model to test their effects on population growth rate. Both site and contact interaction were important to explaining variation in survival and growth. Contact interactions decreased the survival and growth of larger colonies but unexpectedly increased the survival of small colonies at some sites, which led to relatively weaker and spatially variable effects on overall population growth rates. Site effects on population growth rates were an order of magnitude larger than contact effects, and site variation in winter vital rates made the largest contributions to changes in population growth rate. The results of this study suggest that the abiotic environment plays a larger role in the success of B. violaceus. Thus, environmental variables, such as temperature and salinity, could be used to predict this exotic species’ success under different environmental scenarios, including global climate change.


Botrylloides violaceus Competition Exotic species Life table response experiment Matrix model 

Supplementary material

442_2011_1931_MOESM1_ESM.doc (3 mb)
Supplementary material (DOC 3044 kb)


  1. Akaike H (1974) A new look at the statistical model identification. IEEE Trans Automat Control 19:716–723CrossRefGoogle Scholar
  2. Amarasekare P (2002) Interference competition and species coexistence. Proc R Soc Lond B 269:2541–2550CrossRefGoogle Scholar
  3. Benton TG, Grant A (1999) Elasticity analysis as an important tool in evolutionary and population ecology. Trends Ecol Evol 14:467–471PubMedCrossRefGoogle Scholar
  4. Berrill NJ (1947) The developmental cycle of Botrylloides. Q J Microsc Sci 88:393–407PubMedGoogle Scholar
  5. Bruno JF, Fridley JF, Bromberg KD, Bertness MD (2005) Insights into biotic interactions from studies of species invasions. Species invasions: insights into ecology, evolution and biogeography. Sinauer, SunderlandGoogle Scholar
  6. Buhle ER, Margolis M, Ruesink JL (2005) Bang for buck: cost-effective control of invasive species with different life histories. Ecol Econ 52:355–366Google Scholar
  7. Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical- theoretic approach, 2nd edn. Springer, BerlinGoogle Scholar
  8. Burns JH (2008) Demographic performance predicts invasiveness of species in the Commelinaceae under high-nutrient conditions. Ecol Appl 18:335–346PubMedCrossRefGoogle Scholar
  9. Buss LW (1990) Competition within and between encrusting clonal invertebrates. Trends Ecol Evol 5:352–356PubMedCrossRefGoogle Scholar
  10. Carlsson NOL, Sarnelle O, Strayer DL (2009) Native predators and exotic prey—an acquired taste? Front Ecol Environ 7:525–532CrossRefGoogle Scholar
  11. Caswell H (2001) Matrix population models. Sinauer, SunderlandGoogle Scholar
  12. Connell JH (1961) Influence of interspecific competition and other factors on distribution of barnacle Chthamalus Stellatus. Ecology 42:710–723CrossRefGoogle Scholar
  13. Dayton PK (1971) Competition, disturbance, and community organization: the provision and subsequent utilization of space in a rocky intertidal community. Ecol Monogr 41:351–389CrossRefGoogle Scholar
  14. Dias GM, Delboni CGM, Duarte LFL (2008) Effects of competition on sexual and clonal reproduction of a tunicate: the importance of competitor identity. Mar Ecol Prog Ser 362:149–156CrossRefGoogle Scholar
  15. Dudas SE, Dower JF, Anholt BR (2007) Invasion dynamics of the varnish clam (Nuttallia obscurata): a matrix demographic modeling approach. Ecology 88:2084–2093PubMedCrossRefGoogle Scholar
  16. Elton CS (1958) The ecology of invasions by animals and plants. Methuen, LondonGoogle Scholar
  17. Emery SM, Gross KL (2005) Effects of timing of prescribed fire on the demography of an invasive plant, spotted knapweed Centaurea maculosa. J Appl Ecol 42:60–69CrossRefGoogle Scholar
  18. Epelbaum A, Herborg LM, Therriault TW, Pearce CM (2009) Temperature and salinity effects on growth, survival, reproduction and potential distribution of two non- indigenous botryllid ascidians in British Columbia. J Exp Mar Biol Ecol 369:43–52CrossRefGoogle Scholar
  19. Grey EK (2009) Do we need to jump in? A comparison of two survey methods of exotic ascidians on docks. Aquat Invasions 4:81–86CrossRefGoogle Scholar
  20. Grey EK (2010) Large enemy effects on exotic species success in marine fouling communities of Washington, USA. Mar Ecol Prog Ser 411:89–100CrossRefGoogle Scholar
  21. Jackson JBC (1977) Competition on marine hard substrata: the adaptive significance of solitary and colonial strategies. Am Nat 111:743–767CrossRefGoogle Scholar
  22. Jacquemyn H, Brys R, Neubert MG (2005) Fire increases invasive spread of Molinia caerulea mainly through changes in demographic parameters. Ecol Appl 15:2097–2108CrossRefGoogle Scholar
  23. Keane RM, Crawley MJ (2002) Exotic plant invasions and the enemy release hypothesis. Trends Ecol Evol 17:164–170CrossRefGoogle Scholar
  24. Koop AL, Horvitz CC (2005) Projection matrix analysis of the demography of an invasive, nonnative shrub (Ardisia elliptica). Ecology 86:2661–2672CrossRefGoogle Scholar
  25. Lambert G (2005) Ecology and natural history of the protochordates. Can J Zool 83:34–50CrossRefGoogle Scholar
  26. Lambert G, Sanamyan K (2001) Distaplia alaskensis sp.nov (Ascidiacea, Aplousobranchia) and other new ascidian records from south-central Alaska, with a redescription of Ascidia columbiana (Huntsman, 1912). Can J Zool 79:1766–1781Google Scholar
  27. Leichter JJ, Witman JD (1997) Water flow over subtidal rock walls: relation to distributions and growth rates of sessile suspension feeders in the Gulf of Maine Water flow and growth rates. J Exp Mar Biol Ecol 209:293–307CrossRefGoogle Scholar
  28. Levine JM, Adler PB, Yelenik SG (2004) A meta-analysis of biotic resistance to exotic plant invasions. Ecol Lett 7:975–989CrossRefGoogle Scholar
  29. Marco DE, Paez SA (2000) Invasion of Gleditsia triacanthos in Lithraea ternifolia Montane forests of central Argentina. Environ Manage 26:409–419PubMedCrossRefGoogle Scholar
  30. McCarthy A, Osman RW, Whitlatch RB (2007) Effects of temperature on growth rates of colonial ascidians: a comparison of Didemnum sp. to Botryllus schlosseri and Botrylloides violaceus. J Exp Mar Biol Ecol 342:172–174CrossRefGoogle Scholar
  31. Mitchell CE, Agrawal AA, Bever JD, Gilbert GS, Hufbauer RA, Klironomos JN, Maron JL, Morris WF, Parker IM, Power AG, Seabloom EW, Torchin ME, Vazquez DP (2006) Biotic interactions and plant invasions. Ecol Lett 9:726–740PubMedCrossRefGoogle Scholar
  32. Mönkkönen M, Forsman JT, Thomsom RL (2004) Qualitative geographical variation in interspecific interactions. Ecography 27:112–118CrossRefGoogle Scholar
  33. Mook D (1976) Studies on fouling invertebrates in Indian River. 1. Seasonality of settlement. Bull Mar Sci 26:610–615Google Scholar
  34. Mukai H, Saito Y, Watanabe H (1987) Viviparous development in Botrylloides (compound ascidian). J Morphol 193:263–276CrossRefGoogle Scholar
  35. Neubert MG, Caswell H (2000) Demography and dispersal: calculation and sensitivity analysis of invasion speed for structured populations. Ecology 81:1613–1628CrossRefGoogle Scholar
  36. Newell RC, Bayne BL (1973) A review on temperature and metabolic acclimation in intertidal marine invertebrates. Neth J Sea Res 7:421–433CrossRefGoogle Scholar
  37. Nydam M, Stachowicz JJ (2007) Predator effects on fouling community development. Mar Ecol Prog Ser 337:93–101CrossRefGoogle Scholar
  38. Osman RW, Whitlatch RB (1996) Processes affecting newly-settled juveniles and the consequences to subsequent community development. Invertebr Reprod Dev 30:217–225CrossRefGoogle Scholar
  39. Paine RT (1974) Intertidal community structure. Experimental studies on the relationship between a dominant competitor and its principal predator. Oecologia 15:93–120CrossRefGoogle Scholar
  40. Parker IM (2000) Invasion dynamics of Cytisus scoparius: a matrix model approach. Ecol Appl 10:726–743CrossRefGoogle Scholar
  41. Pechenik JA, Berard R, Kerr L (2000) Effects of reduced salinity on survival, growth, reproductive success, and energetics of the euryhaline polychaete Capitella sp I. J Exp Mar Biol Ecol 254:19–35PubMedCrossRefGoogle Scholar
  42. Pennings SC, Silliman BR (2005) Linking biogeography and community ecology: latitudinal variation in plant–herbivore interaction strength. Ecology 86:2310–2319CrossRefGoogle Scholar
  43. Peterson AT (2003) Predicting the geography of species invasions via ecological niche modeling. Q Rev Biol 78:419–433PubMedCrossRefGoogle Scholar
  44. Pimentel D, McNair S, Janecka J, Wightman J, Simmonds C, O’Connell C, Wong E, Russel L, Zern J, Aquino T, Tsomondo T (2001) Economic and environmental threats of alien plant, animal, and microbe invasions. Agric Ecosyst Environ 84:1–20CrossRefGoogle Scholar
  45. Saito Y, Mukai H, Watanabe H (1981) Studies on Japanese compound styelid ascidians: 2 A New species of the genus Botrylloides and redescription of B. violaceus Oka. Publ Seto Mar Biol Lab 26:357–368Google Scholar
  46. Sanford E, Roth MS, Johns GC, Wares JP, Somero GN (2003) Local selection and latitudinal variation in a marine predator–prey interaction. Science 200:1135–1137CrossRefGoogle Scholar
  47. Scavia D, Field JC, Boesch DF et al (2002) Climate change impacts on U.S. coastal and marine ecosystems. Estuaries 25:149–164CrossRefGoogle Scholar
  48. Shea K, Kelly D (1998) Estimating biocontrol agent impact with matrix models: Carduus nutans in New Zealand. Ecol Appl 8:824–832CrossRefGoogle Scholar
  49. Sibley RM, Hone J (2002) Population growth rate and its determinants: an overview. Philos Trans R Soc Lond B 3:1153–1170CrossRefGoogle Scholar
  50. Stachowicz JJ, Whitlatch RB, Osman RW (1999) Species diversity and invasion resistance in a marine ecosystem. Science 286:1577–1579PubMedCrossRefGoogle Scholar
  51. Stachowicz JJ, Terwin JR, Whitlatch RB, Osman RW (2002) Linking climate change and biological invasions: ocean warming facilitates nonindigenous species invasions. Proc Natl Acad Sci USA 99:15497–15500PubMedCrossRefGoogle Scholar
  52. Stoner DS (1990) Recruitment of a tropical colonial ascidian: relative importance of pre-settlement vs. post-settlement processes. Ecology 71:1682–1690CrossRefGoogle Scholar
  53. Sutherland JP, Karlson RH (1977) Development and stability of fouling community at Beaufort North-Carolina. Ecol Monogr 47:425–446CrossRefGoogle Scholar
  54. Thompson JN (1988) Variation in interspecific interactions. Annu Rev Ecol Syst 19:65–87CrossRefGoogle Scholar
  55. Travis J (1996) The significance of geographical variation in species interactions. Am Nat 148:S1–S8CrossRefGoogle Scholar
  56. Vitousek PM, DAntonio CM, Loope LL, Westbrooks R (1996) Biological invasions as global environmental change. Am Sci 84:468–478Google Scholar
  57. Werner PA, Caswell H (1977) Population-growth rates and age versus stage-distribution models for teasel (Dipsacus-Sylvestris-Huds). Ecology 58:1103–1111CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Department of Ecology and Evolutionary BiologyTulane UniversityNew OrleansUSA

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