Mark Bertness: Facilitating Community Ecology Presented by:
Laura Brown BIOL 7083
Slide 2
Background Born July 13, 1949 WA B.S. University of Puget Sound
(psychology/chemistry) M.S. Western Washington University (Biology)
Ph.D University of Maryland (evolutionary ecology) Geerat
Vermeij
Slide 3
Tree Jonathan M. Levine Brian Silliman John Bruno ME!
Slide 4
Research Overview Consumer control of salt marshes Human
impacts on coastal ecosystems Role of foundation species and
positive interactions in community organization Climate change
impacts on coastal ecosystems Historical states of impacted
ecosystems
Slide 5
Cross section of a southern New England salt marsh illustrating
the major vegetation zones and general results of this paper.
Bertness M D et al., 2002 2002 by National Academy of Sciences
Increasing Competition Increasing Physical Constraints
Slide 6
Slide 7
Spartina alterniflora Zone
Slide 8
Slide 9
Slide 10
Slide 11
Roots and rhizomes provide structural support Increases above
ground biomass Soil drainage Soil oxidation reduction potential In
situ decomposition of below- ground plant debris Facilitative
Mutualism! Bertness 1985 TreatmentNumber of StemsBiomass (g) With
Fiddlers23.12.420.62.5 Without Fiddlers13.31.415.71.8
Slide 12
Spartina patens Zone
Slide 13
Bertness 1991 Lower bound is set by environmental stress
Slide 14
Bertness 1991 Spartina patens Zone
Slide 15
Juncus gerardii Zone
Slide 16
Wrack!
Slide 17
Salicornia and Distichlis
Slide 18
Juncus Zone Initial colonizers Shade substrate Alleviate salt
stress Bertness and Shumway 1993
Slide 19
Bertness 1992
Slide 20
Rocky Intertidal Bertness 1989
Slide 21
Community Structure Time Spatial heterogeneity Competition
Predation Climatic stability Productivity Predation Hypothesis
Dominant predators keep species diversity high by reducing
monopolizers Competition hypothesis Highly diverse communities
arise in environments that are stable and result from competition
managed niches Menge and Sutherland 1976
Slide 22
Menge and Sutherland 1987
Slide 23
Community Structure Menge and Sutherland 1987
Slide 24
Positive interactions in communities Bertness and Callaway 1994
Current concepts of the role of interspecific interactions in
communities have been shaped by a profusion of experimental studies
of interspecific competition over the past few decades. Evidence
for the importance of positive interactions- facilitations- in
community organization and dynamics has accrued to the point where
it warrants formal inclusion into community ecology theory, as it
has been in evolutionary biology.
Slide 25
The greater influence between competition and positive
interactions? Bertness and Callaway 1994
Slide 26
Slide 27
Facilitation Study TypeBenthics % MEPS % Facilitation3.42.2
Predation15.110.6 Propagule Supply 12.36.1 Disturbance6.84.2
Competition2.71.2 Shaded = Facilitation Open = Competition Brooker
et al., 2008
Slide 28
Slide 29
Bruno, Stachowicz and Bertness 2003 Facilitation Niche Concept
S. alterniflora zone stabilization
Slide 30
Bruno, Stachowicz and Bertness 2003 Facilitation Niche Concept
S. alterniflora zone stabilization Environmental Stress Desert
shrubs reduce soil temp, but outcompete for shade
Slide 31
Bruno, Stachowicz and Bertness 2003 Facilitation Niche Concept
S. alterniflora zone stabilization Environmental Stress Desert
shrubs reduce soil temp, but outcompete for shade Invasibility with
higher richness
Slide 32
Bruno, Stachowicz and Bertness 2003 Facilitation Niche Concept
S. alterniflora zone stabilization Environmental Stress Desert
shrubs reduce soil temp, but outcompete for shade Invasibility with
higher richness Keystone species Intermediate Disturbance
Hypothesis Keystone species and species within those species
Slide 33
Facilitation
Slide 34
Community Structure Menge and Sutherland 1987
Slide 35
Facilitation IntraspecificInterspecific Bruno, Stachowicz and
Bertness 2003
Slide 36
Conclusion CompetitionPredation Facilitation
Slide 37
Mark Bertness
Slide 38
Citations Bertness, M.D. 1985. Fiddler crab regulation of
Spartina alterniflora production on a New England salt marsh.
Ecology 66:1042-1055. Bertness, M.D. 1989. Intraspecific
competition and facilitation in a northern acorn barnacle
population. Ecology 70:257-268. Bertness, M.D. 1991. Zonation of
Spartina patens and Spartina alterniflora in a New England salt
marsh. Ecology 72:138-148. Bertness, M.D. 1992. Ecology of New
England salt marsh. American Scientist 80:260-268. Bertness, M.D.,
P.J. Ewanchuk and B.R. Silliman. 2002. Anthropogenic modification
of New England salt marsh landscapes. 99:13985-1398. Bertness, M.D.
and R. Callaway. 1994. Positive interactions in communities. Tree
9:191-193. Bertness, M.D. and S.W. Shumway. 1993. Competition and
facilitation in marsh plants. The American Naturalist 142:718-724.
Brooker, R.W. F.T. Maestre, R.M. Callaway, C.L.Lortie, L.A.
Cavieres, G. Kunstler, P. Liancurt, K. Tielborger, J.M.J. Travis,
F. Anthelme, C. Armas, L. Coll, E. Corcket, S. Delzon, E. Forey, Z.
Kikvidze, J. olofsson, F. Pugnaire, C.L. Quiroz, P. Saccone, K.
Schiffers, M. Seifan, B. Touzard, and R. Michalet. 2008. Journal of
Ecology 96:18-34. Bruno, J.F., J.J. Stachowicz, and M.D. Bertness.
2003. Inclusion of facilitation into ecological theory. Trends in
Ecology and Evolution 18:119-125 Menge, B.A. and J.P. Sutherland.
1976. Species diversity gradients: synthesis of the roles of
predation, competition, and temporal heterogeneity. The American
Naturalist 110:351-369. Menge, B.A. and J.P. Sutherland. 1987.
Community regulation: variation in disturbance, competition, and
predation in relation to environmental stress and recruitment. The
American Naturalist 130:730-757.