Inclusion of facilitation into ecological theory

Trends in Ecology & Evolution, Journal Year: 2003, Volume and Issue: 18(3), P. 119 - 125

Published: March 1, 2003

Language: Английский

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Tree-Grass Interactions in Savannas

Annual Review of Ecology and Systematics, Journal Year: 1997, Volume and Issue: 28(1), P. 517 - 544

Published: Nov. 1, 1997

Savannas occur where trees and grasses interact to create a biome that is neither grassland nor forest. Woody gramineous plants by many mechanisms, some negative (competition) positive (facilitation). The strength sign of the interaction varies in both time space, allowing rich array possible outcomes but no universal predictive model. Simple models coexistence grasses, based on separation rooting depth, are theoretically experimentally inadequate. Explanation widely observed increase tree biomass following introduction commercial ranching into savannas requires inclusion interactions among browsers, grazers, fires, their effects recruitment. Prediction consequences manipulating through clearing further an understanding how modify light, water, nutrient environments grasses. Understanding nature between grass, which under other circumstances mutually exclusive or unequal partners, yields theoretical insights has practical implications.

Language: Английский

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COMPETITION AND FACILITATION: A SYNTHETIC APPROACH TO INTERACTIONS IN PLANT COMMUNITIES

Ecology, Journal Year: 1997, Volume and Issue: 78(7), P. 1958 - 1965

Published: Oct. 1, 1997

Interactions among organisms take place within a complex milieu of abiotic and biotic processes, but we generally study them as solitary phenomena. Complex combinations negative positive interactions have been identified in number plant communities. The importance these two processes structuring communities can best be understood by comparing along gradients stress, consumer pressure, different life stages, sizes, densities the interacting species. Here, discuss roles stage, physiology, indirect interactions, physical environment on balance competition facilitation

Language: Английский

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Positive interactions among alpine plants increase with stress

Nature, Journal Year: 2002, Volume and Issue: 417(6891), P. 844 - 848

Published: June 1, 2002

Language: Английский

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Facilitation in plant communities: the past, the present, and the future

Journal of Ecology, Journal Year: 2007, Volume and Issue: 96(1), P. 18 - 34

Published: Sept. 6, 2007

1 Once neglected, the role of facilitative interactions in plant communities has received considerable attention last two decades, and is now widely recognized. It timely to consider progress made by research this field. 2 We review development facilitation research, focusing on history field, relationship between plant–plant environmental severity gradients, attempts integrate into mainstream ecological theory. then future directions for research. 3 With respect our fundamental understanding facilitation, clarification gradients central further progress, necessitates design implementation experiments that move beyond clear limitations previous studies. 4 There substantial scope exploring indirect effects communities, including their impacts diversity evolution, studies should connect degree non-transitivity competitive networks community promotion species coexistence, explore how varies with severity. 5 Certain modelling approaches (e.g. individual-based modelling), although thus far largely provide highly useful tools these processes. 6 Evolutionary responses might result from interactions, consideration lead re-assessment evolution growth forms. 7 Improved processes direct relevance ecosystem restoration, improving response change drivers. 8 Attempts apply developing knowledge would benefit explicit recognition potential interpretation fields restoration global ecology. 9 Synthesis: Plant provides new insights classic theory pressing issues. Awareness be part basic all ecologists.

Language: Английский

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Elton Revisited: A Review of Evidence Linking Diversity and Invasibility

Oikos, Journal Year: 1999, Volume and Issue: 87(1), P. 15 - 15

Published: Oct. 1, 1999

It is commonly believed that diverse communities better resist invasion by exotic species than do simple communities. We examined the history of this notion, and evaluated theoretical empirical work linking diversity invasions. found much historical has contributed to perception are less invasible, including Elton's observations MacArthur's species-packing diversity-stability models, based on controversial premises. Nevertheless, more recent studies consistently supported predicted negative relationship between invasibility. The results studies, however, were decidedly mixed. Constructed community directly manipulating both positive effects invasibility in field microcosm settings. Other tracking assembly ecological generally suggested decline as accumulate over time, though role itself was often ambiguous. Studies spatial correlation experimentally adding invaders natural systems indicated tend be invasible. argue these most likely reflect environmental factors spatially covarying with (e.g. resources, disturbance). not uncovered constructed studies. consistent abundance resident pattern suggests similar believed, implications for theories discussed.

Language: Английский

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Shrub Invasions of North American Semiarid Grasslands

Annual Review of Ecology and Systematics, Journal Year: 2000, Volume and Issue: 31(1), P. 197 - 215

Published: Nov. 1, 2000

▪ Abstract The composition and structure of the semiarid or desert grasslands southwestern North America have changed over past 150 y. Brushy woody species in these communities increased density cover. This increase is called brush encroachment because most been present at lower densities for thousands years. brushy were not introduced from other continents great distances. They are indigenous that cover changes local abiotic biotic conditions. plants cause changes, but their result factors. causes led to woody-brushy has difficult determine. Warming climate seems be a background condition, driving force chronic, high levels herbivory by domestic animals. reduced aboveground grass biomass, leading reduction fine fuel concomitant complete elimination grassland fires. combination factors favors encroachment, establishment, survival growth plants. Less competition grasses, dispersal seeds animals, rodent, lagomorph, insect populations seem modify rate change. Elevated atmospheric CO 2 necessary explain shrub grasslands. direction future change predict. will probably as stature number species. However, if soil nutrients increase, legumes may replaced Reversing going on y difficult, long-term, perhaps impossible, task.

Language: Английский

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Plant Competition Underground

Annual Review of Ecology and Systematics, Journal Year: 1997, Volume and Issue: 28(1), P. 545 - 570

Published: Nov. 1, 1997

Belowground competition occurs when plants decrease the growth, survival, or fecundity of neighbors by reducing available soil resources. Competition belowground can be stronger and involve many more than aboveground competition. Physiological ecologists population community have traditionally studied from different perspectives. Physiologically based studies often measure resource uptake without determining integrated consequences for plant performance, while level examine performance but fail to identify intermediary mechanism. competitive ability is correlated with such attributes as root density, surface area, plasticity either in growth properties enzymes involved nutrient uptake. Unlike light, which larger a disproportionate advantage shading smaller ones, resources apparently symmetric. decreases increases levels, it premature generalize about relative importance above- across gradients. Although shoot are assumed additive effects on some provide evidence contrary, potential interactions between two forms should considered future investigations. Other research recommendations include simultaneous study gaps, since their closures may not occur simultaneously, improved estimates neighborhood. Only combining tools perspectives physiological ecology biology we fully understand how characteristics, neighborhood structure, global climate change influence influenced belowground.

Language: Английский

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Mutualism, Facilitation, and the Structure of Ecological Communities

BioScience, Journal Year: 2001, Volume and Issue: 51(3), P. 235 - 235

Published: Jan. 1, 2001

Language: Английский

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THE INTERPLAY OF FACILITATION AND COMPETITION IN PLANT COMMUNITIES

Ecology, Journal Year: 1997, Volume and Issue: 78(7), P. 1966 - 1975

Published: Oct. 1, 1997

If plants cannot simultaneously acclimate to shade and drought because of physiological trade-offs, then are expected be less tolerant shading under drier conditions. One observation that, at first sight, seems incompatible with this idea is the fact that establishment new in dry areas often restricted shady sites canopy other plants, called "nurse plants." We use a graphical model resolve paradox. The visualizes how facilitative patterns can understood from simultaneous effects plant canopies on microsite light moisture, growth responses establishing seedlings those factors. approach emphasizes positive negative always occur simultaneously. In presented light–water model, facilitation only occurs when improvement water relations exceeds costs caused by lower levels. This may true conditions, whereas situations, competition rather than observed. shows changes availability shift interactions competitive vice versa, as observed some field patterns. It argued environmental factors explaining same context.

Language: Английский

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