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Successional Theory

Successional Theory. ENV 794 Gretchen Andrew Heidi McMaster Caryn Wright March 21, 2011. Ecological Development Terminology. Disturbance – an event, either natural or anthropogenic, that affects an ecosystem’s structure, content or function ( Clewell & Aronson, 2007)

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Successional Theory

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  1. Successional Theory ENV 794 Gretchen Andrew Heidi McMaster Caryn Wright March 21, 2011

  2. Ecological Development Terminology • Disturbance – an event, either natural or anthropogenic, that affects an ecosystem’s structure, content or function (Clewell & Aronson, 2007) • Succession – process that follows a disturbance to an ecosystem by which biota sequentially occupy and replace each other over time (Kimmins, 1997) • Chronosequence – a sequence of communities that characterizes a range of time since a disturbance (Molles, 2008)

  3. Primary succession – when a community develops on a site that isn’t established with biota i.e. a sand or silt bed, a body of water, volcanic flow (Cunningham et al., 2006) http://www.sciencebitz.com/wp-content/uploads/2008/01/primary-success.jpg

  4. Primary Ecological Development • Pioneer Species – the first hardy species (generally microbes) that colonize an area • I.e. - Lichens, moss are able to tolerate harsh conditions creating patches of organic material where debris accumulates providing soil where seeds are able to germinate • Communities become more diverse and competitive • The environmental conditions change and become richer, there is increased moisture and nutrient availability and shelter for species Cunningham, et al., 2006

  5. Secondary Ecological Development • Secondary Succession – abandoned agricultural area or deforested site resulting in bare soil • Initially colonized by annuals that are opportunistic, r-selected species (Abella’s lecture) • Perennials replace annuals

  6. Secondary succession – when a community exists and is disrupted by a fire or flood, deforestation, plowing or mining, and then replaced by another community type (Cunningham et al., 2006) Image source: http://www.sciencebitz.com/wp-content/uploads/2008/01/secondary-success.jpg

  7. Glacier Bay, Alaska • 1794 – Captain George Vancouver • 1879 – John Muir • 1915 – William Cooper • Observed that as the glacier retreated different species established themselves • The site was ideal for studying succession because of the past history recorded

  8. Theory • In both primary and secondary succession it was observed that communities reach a state that becomes resilient to further change • Analogy was made comparing the individual organism development and ecosystem development • It was observed that individual species and communities both began at a juvenile state and developed reaching a complex or mature form Cunningham, et al., 2006

  9. Henry Chandler Cowles • Cowles was among the first to formally identify the theory of succession through his 1899 paper The Ecological Relations of the Vegetation on the Sand Dunes of Lake Michigan

  10. Image source: http://www.nature.com/scitable/knowledge/library/succession-a-closer-look-13256638

  11. Integrated vs Individualistic • Integrated Hypothesis - F. E. Clements, that a community is an assemblage of closely linked species, locked into association by mandatory biotic interactions that cause the community to function as an integrated unit • Individualistic Hypothesis - H. A. Gleason, that a plant community is a chance assemblage of species found in the same area simply because they happen to have similar biotic requirements.

  12. Clements Community-unit theory • Frederic E. Clements – likened ecosystem succession to a relay where species replace one another in predictable groups in a predictable order (Cunningham, et al., 2006) • argued that each ecosystem had a characteristic climax community determined by climate and if undisturbed would reach a characteristic composition

  13. Henry GleasonIndividualistic Hypothesis • Gleason argued succession was a less predictable process • Emphasized chance individual species assemblages rather than community associations • Whitaker and Curtis continued his research with the “species-individualistic model” or “alternative continuum model” plant communities change gradually along complex environmental gradients

  14. Rivet Model - Paul and Anne Ehrlich, that many or most of the species in a community are associated tightly with other species in a web of life. • Redundancy Model - Henry Gleason and Brian Walker, that most of the species in a community are not tightly coupled with one another (that is, the web of life is very loose).

  15. Biomass Accumulation Model Image source:www.biol.vt.edu/faculty/valett/strmecol/.../Lect%2019%20Succession.ppt

  16. Disturbance Adapted Ecosystems • Some ecosystems never reach a “stable” state in the Clements sense but rather are used to periodic disturbances like fires or floods • Fires - eliminate competition and assist in seed germination • Disturbances are a natural part of some ecosystems Image source: http://research.uvu.edu/Gray/previous.htm

  17. Invasive Species • Succession requires a continuous introduction of species (Cunningham, et al., 2006) • This can be problematic if a non-native introduced species becomes invasive or noxious Image source: http://www.cal-ipc.org/ip/management/plant_profiles/Bromus_madritensis.php

  18. References Abella, S. R. 25 March 2010. Disturbance and Plant Succession in the Mojave and Sonoran Deserts of the American Southwest . Int. J. Environ. Res. Public Health 2010, 7, 1248-1284; doi:10.3390/ijerph7041248. Cunningham & Cunningham. Principles of Environmental Science. 2006. Gleason, H. A. 1926 - The individualistic concept of the plant association. Bull. Torrey Bot. Club 53: 7-26. Goodall, D. W. 1963 - The continuum and the individualistic association. Vegetation I : 297-316. Molles, M.C. Ecology Concepts and Applications. 2008. Whittaker, R. H.. 1972. Evolution and Measurement of Species Diversity. Taxon. Vol. 21, No. 2/(May, 1972), pp. 213-251Published by: International Association for Plant Taxonomy (IAPT) http://www.jstor.org/stable/1218190

  19. Bridging Succession Theory and Ecological Restoration Presented by: Gretchen Andrew ENV 794 March 21, 2011 Image source: http://www.matthew-and-maria.com/?p=25

  20. Presentation Outline • Relevance of Topic • Arguments & Justifications • Mutual Benefits • Application of Successional Theory in Restoration • Conclusion Image source: desertmuseum.org

  21. Why is this topic important? “Practicing restoration outside the framework of succession may be likened to building bridges without attending to the law of physics.” Walker et al., 2007b “Current management focuses on eliminating weeds rather than understanding and manipulating the ecological processes and mechanisms promoting invasion and species compositional changes.” Sheley et al., 2006 “Restoration is the acid test of our ability to understand not only how ecosystems are assembled and held together but also how they change over time.” Walker et al., 2007a

  22. Arguments Against the Application • Successional patterns can be unpredictable • Succession too slow a process to apply to restoration • The differences between the two disciplines are too great • Time scales • Spatial scales • Subject matter • Paradigms Walker, et al. 2007b Photo source: exchristian.net

  23. Justification for the Application • Restoration already relies on broader successional patterns of change for its success • Succession is all about how species & substrate change over time, & restoration is all about manipulating those changes • Each discipline can offer understanding & insights to the other Photo source: asianjobportal.com Walker, et al. 2007b

  24. What Succession Offers Restoration • Long-term perspective • Short-term predictions • Reference system for likely outcomes • Generalizations of possible trajectories • Understanding of mechanisms Walker, et al. 2007b Image source: clipart.com

  25. What Restoration Offers Succession • Practical data • Corrections to abiotic constraints • Species interactions in particular circumstances • Sustainability of particular succession communities • Practical tests of successional theory • Use of controls • Treatment comparisons • Data / Statistical analysis • Peer-reviewed results Walker, et al. 2007b Image source: lyonperepente.fr

  26. Major Phases of Succession • Amelioration • Dispersal • Colonization • Establishment • Species assembly / ecosystem development • Also represent the major constraints to successful restoration • How might succession theory be applied to overcoming these restraints? del Moral et al. (2007) Image source: ecostudies.org

  27. Amelioration of Abiotic Constraints • Causes • Natural phenomenon • Human activities • Role (in succession & restoration) • Advance recovery of structure & function • Improve fertility • Reduce toxicity • Improve growing conditions for plants • Natural processes • Wind deposits dust, pollen, seeds, insects • Water erosion removes overburden • Frost-thaw cycle fractures rocks • Wind erosion forms microtopography (safe sites) Image source: superstock.com del Moral et al. (2007)

  28. Successional Theory Applied to Amelioration • Lessons from succession • Stress restricts establishment • Safe-site creation important • Low fertility may increase diversity • Application to restoration • Reduce toxicity • Create safe-sites • Increase heterogeneity del Moral et al. (2007) ; Sheley et al. (2006) Image source: debudeodhar.com

  29. Example of Amelioration in Restoration Neil B. Reid, N. B. and M.A. Naeth, 2005. Establishment of a Vegetation Cover on Tundra Kimberlite Mine Tailings: 2. A Field Study. Restoration Ecology, 13(4): 602-608. ekati.bhpbilliton.com www.monitoringagency.net/PhotoGallery

  30. Dispersal • Role • Improve colonization • Increase functional group diversity • Obstacles • Depleted seed bank • Impermeable or inhospitable habitats • Natural processes • Landscape permeability del Moral et al. (2007) Image source: alnus-eco.com

  31. Successional Theory Applied to Dispersal • Lessons from succession • Regional species pool is limited • Chance is important • Application in restoration • Sow/introduce plant species • Install bird perches del Moral et al. (2007) ; Sheley et al. (2006)

  32. Example of Application in Restoration to Improve Dispersal Martínez-Garza, C. and H.F. Howe, 2003. Restoring tropical diversity: beating the time tax on species diversity. Journal of Applied Ecology, 40: 423-429.

  33. Colonization • Role • Speed up ecosystem development • Decrease competition by invasives • Obstacles • Few large-seeded spp on isolated sites • High seeding failure rates • Competition • Seed predation • Natural processes • Spontaneous recolonization • Trajectories started by ruderal species • Trees & shrubs provide refuge to birds & protect seedlings Image source: desertmuseum.org del Moral et al. (2007)

  34. Successional Theory Applied to Colonization • Lessons from succession • Disharmony characterizes early vegetation • Survival probabilities low & random • Natural dispersal doesn’t provide most colonists • Tools for restoration • Introduce array of species • Plant more species than are required del Moral et al. (2007) ; Sheley et al. (2006)

  35. Example of Application in Restoration to Improve Colonization Slocum, M.G. and C.C. Horvitz, 2000. Seed arrival under different genera of trees in a neotropical pasture. Plant Ecology, 149(1): 51-62.

  36. Establishment • Role • Allow seedlings to grow fast enough to survive changing conditions • Obstacles • Drought • Excessive light or heat • Herbivory • Natural processes • Mechanisms that trap seeds • Stable surfaces • Safe-sites del Moral et al. (2007) Image source: travelwebshots.com

  37. Successional Theory Applied to Establishment • Concepts from succession • Functional redundancy • Facilitation • Inhibition • Tools for restoration • Introduce several species in several functional groups • Provide safe-sites • Plant saplings in scattered clusters to provide mutual support • Protect seedlings from herbivores (e.g., fencing) del Moral et al. (2007)

  38. Example of Application in Restoration to Improve Establishment Urbanska, K.M., 1995. Biodiversity assessment in ecological restoration above the timberline. Biodiversity & Conservation, 4: 679-695. Jakobshorn, Davos, Switzerland

  39. Conclusion • Succession theory and ecological restoration are inherently linked • Despite the differences between the two disciplines, each has much to offer the other in terms of knowledge & insights • Practical strategies exist for applying succession theory to restoration projects Photo source: fr.treknature.com

  40. Works Cited del Moral, R., L. Walker, J. Bakker, 2007. Insights gained from succession for the restoration of landscape structure and function. In: Linking restoration and ecological succession, Walker, L. R., Walker, J., R.J. Hobbs (Eds), Springer, New York, N.Y., 1-18. Martínez-Garza, C. and H.F. Howe, 2003. Restoring tropical diversity: beating the time tax on species diversity. Journal of Applied Ecology, 40: 423-429. Neil B. Reid, N. B. and M.A. Naeth, 2005. Establishment of a Vegetation Cover on Tundra Kimberlite Mine Tailings: 2. A Field Study. Restoration Ecology, 13(4): 602-608. Sheley, R.L., J.M. Mangold, J.L. Anderson. 2006. Potential for successional theory to guide restoration of invasive-plant-dominated rangeland. Ecological Monographs, 76(3):365-379. Slocum, M.G. and C.C. Horvitz, 2000. Seed arrival under different genera of trees in a neotropical pasture. Plant Ecology, 149(1): 51-62. Walker, L.R., E. Velazquez, A.B. Shiels. 2009. Applying lessons from ecological succession to the restoration of landslides. Plant and Soil, 324(1-2):157-168. Walker, L. R., Walker, J., R.J. Hobbs (eds), 2007a. Linking restoration and ecological succession. Springer, New York, N.Y., 190 pp. Walker, L. R., J. Walker, and R. del Moral, 2007b. Forging a new alliance between succession and restoration. In: Linking restoration and ecological succession. Walker, L. R., Walker, J., R.J. Hobbs (Eds), Springer, New York, N.Y., 1-18. Urbanska, K.M., 1995. Biodiversity assessment in ecological restoration above the timberline. Biodiversity & Conservation, 4: 679-695.

  41. Ecological Succession- Theory applied to real life examples • Topics of interest • Succession significance and background • Obtaining “equilibrium” • Is it possible • Disturbance • Succession examples • Problems facing future restoration efforts and succession predictions in new areas

  42. Background and the significance of Succession in Ecology Ecological succession studies are particularly important when it comes to addressing concerns about biodiversity loss, climate change, invasive species, and ecological restoration.

  43. Background and the significance of Succession in Ecology cont. • Historical succession models are used as a predictor of changes in biodiversity and ecosystem services impacted by invasive species and climate change. • Understanding succession of different climates, gives restorers a better idea of how to manage these new ecosystem areas. • Invasive species are a concern to ecologists and those relying on succession traits known to an area. • Tamarisk is an invasive species threatening portions of the newly exposed shore line of Lake Mead National Recreation Area. • It is important to address concerns about invasive • species when discussing succession because these • invasives are not part of the “natural” cycle of succession.

  44. Some examples of different types of “succession” The theory of succession addresses the dynamics. There is not any particular “end-point” as it is always changing. Tree saplings found here at the bottom of a dry river bed. Most of these species will be washed away when the river fills up with water with winter snow melt. During the dry period, perennials, grasses and some tree saplings have begun to populate this exposed area. However, this new area will change again with the spring thaw.

  45. Some examples of different types of “succession” cont. From another extreme, this forest has been under going succession for a very long time. Forest vegetation pushing up the side of an old cinder cone volcano after eruption This particular site has been a 10,000 year battle up hill. www.morning-earth.org/graphic-e/Transf-Success.htm

  46. Some examples of different types of “succession” cont. An example of a moderate successional change. Succession example of an old plowed field being encroached upon by vegetation.

  47. Factors that change succession possibilities • Issues inhibiting the use succession history. Issues scientists are facing in predicting succession: • Perchlorate in the water in Lake Mead- what might this chemical be changing in the succession dynamics on the Lake Mead shore line? • Invasive species- quagga and zebra muscles, tamarisk, brome, Russian thistle • Climate change- temperatures are different than historical succession models of the area • Human interference- both with restoration and continuous disturbance http://worldwaders.posterous.com/north-brigantine-natural-area-experimental-cl http://ecology.ucdavis.edu/programs/restoration/ecolrestore.html

  48. Factors that change succession possibilities cont. • “Global warming may intensify the hydrological cycle and lead to increased drought severity and duration, which could alter plant community structure and subsequent ecosystem water and carbon dioxide cycling.” (Scott, et al 2010) • Drought conditions not usual to an area can have affects on the plant species composition. • As native species die off due to water and moisture changes, it makes way for drought tolerant species to colonize an area, thereby changing the historical pattern of succession. • Characteristic questions facing ecologists: • When does an exotic species become a part of the “natural” ecosystem? • Is the exotic/invasive species part of the larger natural process?

  49. Historical and current succession studies • Polish desert succession • Historical maps used to track vegetation and human habits. • Land originally used by mining for metallurgy in the 13th century. • Narrowed down to primary and secondary succession. • Tracked to cyanobacterial communities holding soils for water retention to make way for annual plants. • Time a factor as well moisture levels and disturbances. Land was reclaimed beginning in 2009 to restore the area as best as possible to pre-disturbance. Cannot restore on its own with current conditions. http://www.krakowpost.com/article/1535

  50. Historical and current succession studies cont. • Lake Huron shoreline trends and water elevation changes • Low and high water trends in lakes can have successional trends over time • Riparian species in areas with the most moisture. • With the receding water to low points, the once moist ground is dry and makes way for grasses and then shrubs. • Species composition changes as water levels decline. http://web1.msue.msu.edu/iosco/openshoreline.htm

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