Journal : Atmosphere, ecology and evolution: what drove the Miocene expansion of C4 grasslands?

Volume 96 Issue 1 Page 35-45, January 2008

To cite this article: Colin P. Osborne (2008) Atmosphere, ecology and evolution: what drove the Miocene expansion of C₄ grasslands?
Journal of Ecology 96 (1) , 35–45 doi:10.1111/j.1365-2745.2007.01323.x

Abstract

ESSAY REVIEW

Atmosphere, ecology and evolution: what drove the Miocene expansion of C₄ grasslands?

• Colin P. Osborne* *Correspondence author. E-mail: c.p.osborne@sheffield.ac.uk

• Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK

*Correspondence author. E-mail: c.p.osborne@sheffield.ac.uk

Key-words: atmospheric CO₂, C₄ plants, climate change, fire, grassland, grazing, Poaceae, rainfall, savanna, seasonality

Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

Summary

1.	Grasses using the C4 photosynthetic pathway dominate today's savanna ecosystems and account for ~20% of terrestrial carbon fixation. However, this dominant status was reached only recently, during a period of C4 grassland expansion in the Late Miocene and Early Pliocene (4–8 Myr ago). Declining atmospheric CO2 has long been considered the key driver of this event, but new geological evidence casts doubt on the idea, forcing a reconsideration of the environmental cues for C4 plant success.
2.	Here, I evaluate the current hypotheses and debate in this field, beginning with a discussion of the role of CO2 in the evolutionary origins, rather than expansion, of C4 grasses. Atmospheric CO2 starvation is a plausible selection agent for the C4 pathway, but a time gap of around 10 Myr remains between major decreases in CO2 during the Oligocene, and the earliest current evidence of C4 plants.
3.	An emerging ecological perspective explains the Miocene expansion of C4 grasslands via changes in climatic seasonality and the occurrence of fire. However, the climatic drivers of this event are debated and may vary among geographical regions.
4.	Uncertainty in these areas could be reduced significantly by new directions in ecological research, especially the discovery that grass species richness along rainfall gradients shows contrasting patterns in different C4 clades. By re-evaluating a published data set, I show that increasing seasonality of rainfall is linked to changes in the relative abundance of the major C4 grass clades Paniceae and Andropogoneae. I propose that the explicit inclusion of these ecological patterns would significantly strengthen climate change hypotheses of Miocene C4 grassland expansion. Critically, they allow a new series of testable predictions to be made about the fossil record.
5.	Synthesis. This paper offers a novel framework for integrating modern ecological patterns into theories about the geological history of C4 plants.

This article is cited by:

• Erika J. Edwards and Christopher J. Still. (2008) Climate, phylogeny and the ecological distribution of C4 grasses. Ecology Letters 11:3, 266–276
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Journal : Methods to account for spatial autocorrelation in the analysis of species distributional data: a review

Volume 30 Issue 5 Page 609-628, October 2007

To cite this article: Carsten F. Dormann, Jana M. McPherson, Miguel B. Araújo, Roger Bivand, Janine Bolliger, Gudrun Carl, Richard G. Davies, Alexandre Hirzel, Walter Jetz, W. Daniel Kissling, Ingolf Kühn, Ralf Ohlemüller, Pedro R. Peres-Neto, Björn Reineking, Boris Schröder, Frank M. Schurr, Robert Wilson (2007) Methods to account for spatial autocorrelation in the analysis of species distributional data: a review
Ecography 30 (5) , 609–628 doi:10.1111/j.2007.0906-7590.05171.x

Abstract

Methods to account for spatial autocorrelation in the analysis of species distributional data: a review

• Carsten F. Dormann,
• Jana M. McPherson,
• Miguel B. Araújo,
• Roger Bivand,
• Janine Bolliger,
• Gudrun Carl,
• Richard G. Davies,
• Alexandre Hirzel,
• Walter Jetz,
• W. Daniel Kissling,
• Ingolf Kühn,
• Ralf Ohlemüller,
• Pedro R. Peres-Neto,
• Björn Reineking,
• Boris Schröder,
• Frank M. Schurr and
• Robert Wilson,

C. F. Dormann (carsten.dormann@ufz.de), Dept of Computational Landscape Ecology, UFZ Helmholtz Centre for Environmental Research, Permoserstr. 15, DE-04318 Leipzig, Germany. – J. M. McPherson, Dept of Biology, Dalhousie Univ., 1355 Oxford Street HAlifax NS, B3H 4J1 Canada. – M. B. Araújo, Dept de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, C/ Gutiérrez Abascal, 2, ES-28006 Madrid, Spain, and Centre for Macroecology, Inst. of Biology, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark. – R. Bivand, Economic Geography Section, Dept of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, NO-5045 Bergen, Norway. – J. Bolliger, Swiss Federal Research Inst. WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland. – G. Carl and I. Kühn, Dept of Community Ecology (BZF), UFZ Helmholtz Centre for Environmental Research, Theodor-Lieser-Strasse 4, DE-06120 Halle, Germany, and Virtual Inst. Macroecology, Theodor-Lieser-Strasse 4, DE-06120 Halle, Germany. – R. G. Davies, Biodiversity and Macroecology Group, Dept of Animal and Plant Sciences, Univ. of Sheffield, Sheffield S10 2TN, U.K. – A. Hirzel, Ecology and Evolution Dept, Univ. de Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland. – W. Jetz, Ecology Behavior and Evolution Section, Div. of Biological Sciences, Univ. of California, San Diego, 9500 Gilman Drive, MC 0116, La Jolla, CA 92093-0116, USA. – W. D. Kissling, Community and Macroecology Group, Inst. of Zoology, Dept of Ecology, Johannes Gutenberg Univ. of Mainz, DE-55099 Mainz, Germany, and Virtual Inst. Macroecology, Theodor-Lieser-Strasse 4, DE-06120 Halle, Germany. – R. Ohlemüller, Dept of Biology, Univ. of York, PO Box 373, York YO10 5YW, U.K. – P. R. Peres-Neto, Dept of Biology, Univ. of Regina, SK, S4S 0A2 Canada, present address: Dept of Biological Sciences, Univ. of Quebec at Montreal, CP 8888, Succ. Centre Ville, Montreal, QC, H3C 3P8, Canada. – B. Reineking, Forest Ecology, ETH Zurich CHN G 75.3, Universitätstr. 16, CH-8092 Zürich, Switzerland. – B. Schröder, Inst. for Geoecology, Univ. of Potsdam, Karl-Liebknecht-Strasse 24-25, DE-14476 Potsdam, Germany. – F. M. Schurr, Plant Ecology and Nature Conservation, Inst. of Biochemistry and Biology, Univ. of Potsdam, Maulbeerallee 2, DE-14469 Potsdam, Germany. – R. Wilson, Área de Biodiversidad y Conservación, Escuela Superior de Ciencias Experimentales y Tecnología, Univ. Rey Juan Carlos, Tulipán s/n, Móstoles, ES-28933 Madrid, Spain.

Abstract

Species distributional or trait data based on range map (extent-of-occurrence) or atlas survey data often display spatial autocorrelation, i.e. locations close to each other exhibit more similar values than those further apart. If this pattern remains present in the residuals of a statistical model based on such data, one of the key assumptions of standard statistical analyses, that residuals are independent and identically distributed (i.i.d), is violated. The violation of the assumption of i.i.d. residuals may bias parameter estimates and can increase type I error rates (falsely rejecting the null hypothesis of no effect). While this is increasingly recognised by researchers analysing species distribution data, there is, to our knowledge, no comprehensive overview of the many available spatial statistical methods to take spatial autocorrelation into account in tests of statistical significance. Here, we describe six different statistical approaches to infer correlates of species’ distributions, for both presence/absence (binary response) and species abundance data (poisson or normally distributed response), while accounting for spatial autocorrelation in model residuals: autocovariate regression; spatial eigenvector mapping; generalised least squares; (conditional and simultaneous) autoregressive models and generalised estimating equations. A comprehensive comparison of the relative merits of these methods is beyond the scope of this paper. To demonstrate each method's implementation, however, we undertook preliminary tests based on simulated data. These preliminary tests verified that most of the spatial modeling techniques we examined showed good type I error control and precise parameter estimates, at least when confronted with simplistic simulated data containing spatial autocorrelation in the errors. However, we found that for presence/absence data the results and conclusions were very variable between the different methods. This is likely due to the low information content of binary maps. Also, in contrast with previous studies, we found that autocovariate methods consistently underestimated the effects of environmental controls of species distributions. Given their widespread use, in particular for the modelling of species presence/absence data (e.g. climate envelope models), we argue that this warrants further study and caution in their use. To aid other ecologists in making use of the methods described, code to implement them in freely available software is provided in an electronic appendix.

This article is cited by:

• Hong Qian. Effects of historical and contemporary factors on global patterns in avian species richness. Journal of Biogeography doi: 10.1111/j.1365-2699.2008.01901.x
  Abstract Abstract and References Full Text Article Full Article PDF
• José Alexandre Felizola Diniz-Filho, Thiago Fernando L. V. B. Rangel and Luis Mauricio Bini. Model selection and information theory in geographical ecology. Global Ecology and Biogeography doi: 10.1111/j.1466-8238.2008.00395.x
  Abstract Abstract and References Full Text Article Full Article PDF
• Hong Qian and Robert E. Ricklefs. Global concordance in diversity patterns of vascular plants and terrestrial vertebrates. Ecology Letters doi: 10.1111/j.1461-0248.2008.01168.x
  Abstract Abstract and References Full Text Article Full Article PDF
• (2008) Editorial: launching Software Notes. Ecography 31:1, 3–3
  Summary Abstract and References Full Text Article Full Article PDF
• José Alexandre F. Diniz-Filho, Bradford A. Hawkins, Luis Mauricio Bini, Paulo De Marco Jr and Tim M. Blackburn,. (2007) Are spatial regression methods a panacea or a Pandora's box? A reply to Beale et al. (2007). Ecography 30:6, 848–851
  Summary Abstract and References Full Text Article Full Article PDF
• Daniel Sol, Montserrat Vilà, Ingolf Kühn. (2007) The comparative analysis of historical alien introductions. Biological Invasions ,
  CrossRef

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Journal : The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial ecosystems

Volume 11 Issue 3 Page 296-310, March 2008

To cite this article: Marcel G. A. van der Heijden, Richard D. Bardgett, Nico M. van Straalen (2008) The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial ecosystems
Ecology Letters 11 (3) , 296–310 doi:10.1111/j.1461-0248.2007.01139.x

Abstract

REVIEW AND SYNTHESIS

The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial ecosystems

• Marcel G. A. van der Heijden^1,2*¹Department of Animal Ecology, Faculty of Earth and Life Sciences, Institute of Ecological Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands²Agroscope Reckenholz-Tänikon, Research Station ART, Reckenholzstrasse 191, 8046 Zurich, Switzerland*E-mail: marcel.vanderheijden@art.admin.ch
• Richard D. Bardgett³³Soil and Ecosystem Ecology, Lancaster University, Lancaster LA1 4YQ, UK and
• Nico M. van Straalen¹¹Department of Animal Ecology, Faculty of Earth and Life Sciences, Institute of Ecological Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands

• ¹Department of Animal Ecology, Faculty of Earth and Life Sciences, Institute of Ecological Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
  ²Agroscope Reckenholz-Tänikon, Research Station ART, Reckenholzstrasse 191, 8046 Zurich, Switzerland
  ³Soil and Ecosystem Ecology, Lancaster University, Lancaster LA1 4YQ, UK

*E-mail: marcel.vanderheijden@art.admin.ch

Abstract

Microbes are the unseen majority in soil and comprise a large portion of life’s genetic diversity. Despite their abundance, the impact of soil microbes on ecosystem processes is still poorly understood. Here we explore the various roles that soil microbes play in terrestrial ecosystems with special emphasis on their contribution to plant productivity and diversity. Soil microbes are important regulators of plant productivity, especially in nutrient poor ecosystems where plant symbionts are responsible for the acquisition of limiting nutrients. Mycorrhizal fungi and nitrogen-fixing bacteria are responsible for c. 5–20% (grassland and savannah) to 80% (temperate and boreal forests) of all nitrogen, and up to 75% of phosphorus, that is acquired by plants annually. Free-living microbes also strongly regulate plant productivity, through the mineralization of, and competition for, nutrients that sustain plant productivity. Soil microbes, including microbial pathogens, are also important regulators of plant community dynamics and plant diversity, determining plant abundance and, in some cases, facilitating invasion by exotic plants. Conservative estimates suggest that c. 20 000 plant species are completely dependent on microbial symbionts for growth and survival pointing to the importance of soil microbes as regulators of plant species richness on Earth. Overall, this review shows that soil microbes must be considered as important drivers of plant diversity and productivity in terrestrial ecosystems.

This article is cited by:

• Gerlinde B. De Deyn, Johannes H. C. Cornelissen and Richard D. Bardgett. (2008) Plant functional traits and soil carbon sequestration in contrasting biomes. Ecology Letters 11:5, 516–531
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Journal : Complementarity as a mechanism of coexistence between functional groups of grasses

Volume 95 Issue 6 Page 1296-1305, November 2007

To cite this article: N GROSS, K. N SUDING, S LAVOREL, C ROUMET (2007) Complementarity as a mechanism of coexistence between functional groups of grasses
Journal of Ecology 95 (6) , 1296–1305 doi:10.1111/j.1365-2745.2007.01303.x

Abstract

Complementarity as a mechanism of coexistence between functional groups of grasses

• N. GROSS*†‡†Laboratoire d’Ecologie Alpine (LECA), UMR 5553 CNRS – Université Joseph Fourier, BP 53, F-38041 Grenoble, France, ‡Station Alpine Joseph Fourier (SAJF), UMS 2579 CNRS – Université Joseph Fourier, BP 53, F-38041 Grenoble, France, *Author to whom correspondence should be addressed: Nicolas Gross. Tel.: +33 4 76 63 54 38. Fax: +33 4 76 51 46 73. E-mail: nicolas.gross@ujf-grenoble.fr.,
• K. N. SUDING§§Department of Ecology and Evolutionary Biology – University of California Irvine, Irvine, CA, 92697–2525, USA, and ,
• S. LAVOREL†‡†Laboratoire d’Ecologie Alpine (LECA), UMR 5553 CNRS – Université Joseph Fourier, BP 53, F-38041 Grenoble, France, ‡Station Alpine Joseph Fourier (SAJF), UMS 2579 CNRS – Université Joseph Fourier, BP 53, F-38041 Grenoble, France, and
• C. ROUMET¶¶Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS – 1919, Route de Mende, 34293 Montpellier, Cedex 5, France

• †Laboratoire d’Ecologie Alpine (LECA), UMR 5553 CNRS – Université Joseph Fourier, BP 53, F-38041 Grenoble, France, ‡Station Alpine Joseph Fourier (SAJF), UMS 2579 CNRS – Université Joseph Fourier, BP 53, F-38041 Grenoble, France, §Department of Ecology and Evolutionary Biology – University of California Irvine, Irvine, CA, 92697–2525, USA, and ¶Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175, CNRS – 1919, Route de Mende, 34293 Montpellier, Cedex 5, France

*Author to whom correspondence should be addressed: Nicolas Gross. Tel.: +33 4 76 63 54 38. Fax: +33 4 76 51 46 73. E-mail: nicolas.gross@ujf-grenoble.fr.

Key-words: biotic interactions, complementarity, dominant species, fertilization, functional groups, grasses, overyielding, subalpine grasslands

Journal of Ecology (2007)
doi: 10.1111/j.1365-2745.2007.01303.x

Summary

1.	Increasing functional diversity often leads to an increase in ecosystem productivity in the form of overyielding. While the mechanisms (i.e. complementarity or facilitation) that underlie overyielding provide strong insights into species coexistence and community assembly, they are rarely tested. In subalpine grasslands, traditional management through manuring and hay-making results in intermediate productivity that is associated with high functional diversity. This functional diversity results from the coexistence between conservative plant species (with slow growth rates, low specific leaf area) and exploitative species (with fast growth rates, high specific leaf area).
2.	We hypothesized that overyielding occurs among these two functional groups and tested whether complementarity or facilitation can explain overyielding. Using three perennial grass species per functional group, we compared single and mixed functional group mesocosms at low and intermediate levels of fertilization to test the occurrence of overyielding. Additionally, we measured the outcomes of biotic interactions among these two functional groups by manipulating plant density.
3.	After two growing seasons, we found evidence of overyielding under intermediate levels of fertility. Overyielding was associated with a reduction of competition intensity when both functional groups were grown together. These results suggest that complementarity, as evidenced by a decrease in competition intensity, rather than facilitation, explains the observed overyielding. Indeed, we found evidence for complementarity for light and modification of nutrient use as possible mechanisms for the overyielding.
4.	Synthesis. Complementarity between functional groups might be an important mechanism enhancing functional diversity, particularly in harsh environments at intermediate rather than low fertility.

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Journal : Exotic invasive plant accumulates native soil pathogens which inhibit native plants

Volume 96 Issue 1 Page 58-67, January 2008

To cite this article: Seema Mangla, Inderjit, Ragan M. Callaway (2008) Exotic invasive plant accumulates native soil pathogens which inhibit native plants
Journal of Ecology 96 (1) , 58–67 doi:10.1111/j.1365-2745.2007.01312.x

Abstract

Exotic invasive plant accumulates native soil pathogens which inhibit native plants

• Seema Mangla ¹¹Centre for Environmental Management of Degraded Ecosystems (CEMDE), University of Delhi, Delhi 110007, India; and ,
• Inderjit ¹*¹Centre for Environmental Management of Degraded Ecosystems (CEMDE), University of Delhi, Delhi 110007, India; and *Correspondence author. E-mail: inderjit@cemde.du.ac.in and
• Ragan M. Callaway ²²Organismal Biology and Ecology, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA

• ¹Centre for Environmental Management of Degraded Ecosystems (CEMDE), University of Delhi, Delhi 110007, India; and ²Organismal Biology and Ecology, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA

*Correspondence author. E-mail: inderjit@cemde.du.ac.in

Key-words: allelopathy, Chromolaena odorata, Fusarium, fungal pathogen, indirect interactions, invasion, soil biota, soil pathogen, root leachate

Summary

1.	We investigated the role of a native generalist soil pathogen through which a non-native invasive plant species may suppress naturalized/native plant species.
2.	We found that rhizosphere soils of Chromolaena odorata, one of the world's most destructive tropical invasive weeds, accumulate high concentrations of the generalist soil borne fungi, Fusarium (tentatively identified as F. semitectum), thus creating a negative feedback for native plant species.
3.	Soils collected beneath Chromolaena in the Western Ghats of India inhibited naturalized/native species and contained over 25 times more spores of the pathogenic fungi Fusarium semitectum than soils collected at the same locations beneath neighbouring native species that were at least 20 m from any Chromolaena plant. Sterilization of these soils eliminated their inhibitory effect. Chromolaena root leachate experimentally added to uninvaded soils increased Fusarium spore density by over an order of magnitude, and increased the inhibitory effect of the soils.
4.	The positive effect of Chromolaena root leachates on Fusarium spores was attenuated by activated carbon, suggesting a biochemical basis for how the invader stimulated the pathogen.
5.	Synthesis. Invasive plants have been shown to escape inhibitory soil biota in their native range and to inhibit soil biota in their invaded range, but our results indicate that the impacts of Chromolaena are due to the exacerbation of biotic interactions among native plants and native soil biota, which is to our knowledge a new invasive pathway.

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Journal : Dispersion of traits related to competitive ability in an old-field plant community

Volume 96 Issue 1 Page 204-212, January 2008

To cite this article: Brandon S. Schamp, Joyce Chau, Lonnie W. Aarssen (2008) Dispersion of traits related to competitive ability in an old-field plant community
Journal of Ecology 96 (1) , 204–212 doi:10.1111/j.1365-2745.2007.01328.x

Abstract

Dispersion of traits related to competitive ability in an old-field plant community

• Brandon S. Schamp*¹¹Department of Biology, Queen's University, Kingston, Ontario K7L 3 N6, Canada, and *Correspondence author. E-mail: schampb@biology.queensu.ca,
• Joyce Chau ^{2 2}Citizens’ Environment Watch, 147 Spadina Avenue, Suite 204, Toronto ON M5V 2L7, Canada and
• Lonnie W. Aarssen ¹¹Department of Biology, Queen's University, Kingston, Ontario K7L 3 N6, Canada, and

• ¹Department of Biology, Queen's University, Kingston, Ontario K7L 3 N6, Canada, and ²Citizens’ Environment Watch, 147 Spadina Avenue, Suite 204, Toronto ON M5V 2L7, Canada

*Correspondence author. E-mail: schampb@biology.queensu.ca

Key-words: coexistence, competitive asymmetry, competition, convergence, divergence, limiting similarity, niche separation, over-dispersion, physical space niche, under-dispersion

Summary

1.	We investigated patterns in the dispersion (i.e. spread and spacing) of plant species traits that are frequently associated with competitive ability, in an old-field plant community. In contrast with previous studies, we found no evidence for significant over- or under-dispersion of maximum plant height, maximum plant biomass, or seed mass.
2.	These findings hold across three plot sizes (10 × 10 cm, 30 × 30 cm, 50 × 50 cm), and when plot size is measured in terms of number of ramets (50 ramets, 250 ramets or 500 ramets) rather than per unit area. Plot size, however, significantly affected the direction of dispersion observed across test statistics, supporting previous studies that have observed that trait dispersion patterns are sensitive to plot size.
3.	While no significant dispersion was detected, dispersion direction, measured as the tendency for a two-tailed test to indicate trends for a given trait, was more frequently observed when analyses were weighted by abundance. Abundance weighted analyses had significantly different dispersion directions compared with presence/absence analyses for one of three traits considered. These findings suggest that abundance weighted analyses may yield more consistent trait dispersion patterns.
4.	Synthesis. Our results may be interpreted as evidence for limited, if any, functional niche partitioning between co-occurring species via size-mediated differences in rooting depth or physical space niches (i.e. limiting similarity). Alternatively, some species with large differences in competitive traits may avoid competition through niche separation, while others may simply compete asymmetrically, leading to overall patterns of dispersion that cannot be distinguished from random. This interpretation supports recent perspectives that niche and neutral theoretical concepts are not mutually exclusive; both, working together, can be applied to the interpretation of plant community assembly and structure.

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Journal : Short- and long-term effects of disturbance and propagule pressure on a biological invasion

Volume 96 Issue 1 Page 68-77, January 2008

To cite this article: Kevin H. Britton-Simmons, Karen C. Abbott (2008) Short- and long-term effects of disturbance and propagule pressure on a biological invasion
Journal of Ecology 96 (1) , 68–77 doi:10.1111/j.1365-2745.2007.01319.x

Abstract

Short- and long-term effects of disturbance and propagule pressure on a biological invasion

• Kevin H. Britton-Simmons* *Correspondence and present address. Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA. E-mail: aquaman@u.washington.edu and
• Karen C. Abbott†

• Department of Ecology and Evolution, The University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA

*Correspondence and present address. Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA. E-mail: aquaman@u.washington.edu

Key-words: biological invasion, biotic resistance, disturbance, establishment probability, propagule pressure, Sargassum muticum

†Present address: Department of Zoology, University of Wisconsin, 430 Lincoln Drive, Madison, WI 53706, USA

Summary

1.	Invading species typically need to overcome multiple limiting factors simultaneously in order to become established, and understanding how such factors interact to regulate the invasion process remains a major challenge in ecology.
2.	We used the invasion of marine algal communities by the seaweed Sargassum muticum as a study system to experimentally investigate the independent and interactive effects of disturbance and propagule pressure in the short term. Based on our experimental results, we parameterized an integrodifference equation model, which we used to examine how disturbances created by different benthic herbivores influence the longer term invasion success of S. muticum.
3.	Our experimental results demonstrate that in this system neither disturbance nor propagule input alone was sufficient to maximize invasion success. Rather, the interaction between these processes was critical for understanding how the S. muticum invasion is regulated in the short term.
4.	The model showed that both the size and spatial arrangement of herbivore disturbances had a major impact on how disturbance facilitated the invasion, by jointly determining how much space-limitation was alleviated and how readily disturbed areas could be reached by dispersing propagules.
5.	Synthesis. Both the short-term experiment and the long-term model show that S. muticum invasion success is co-regulated by disturbance and propagule pressure. Our results underscore the importance of considering interactive effects when making predictions about invasion success.

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Journal : Landscape configuration and flood frequency influence invasive shrubs in floodplain forests of the Wisconsin River (USA)

Volume 96 Issue 1 Page 91-102, January 2008

To cite this article: Katharine I. Predick, Monica G. Turner (2008) Landscape configuration and flood frequency influence invasive shrubs in floodplain forests of the Wisconsin River (USA)
Journal of Ecology 96 (1) , 91–102 doi:10.1111/j.1365-2745.2007.01329.x

Abstract

Landscape configuration and flood frequency influence invasive shrubs in floodplain forests of the Wisconsin River (USA)

• Katharine I. Predick* *Correspondence author. School of Natural Resources, University of Arizona, Biological Sciences East, 1311 E. 4th Street, Tucson, AZ 85721–0043, USA. E-mail: kipredick@arizona.edu and
• Monica G. Turner

• Department of Zoology, University of Wisconsin, Madison, WI 53706, USA

*Correspondence author. School of Natural Resources, University of Arizona, Biological Sciences East, 1311 E. 4th Street, Tucson, AZ 85721–0043, USA. E-mail: kipredick@arizona.edu

Key-words: anthropogenic disturbance, exotic species, flood regime, landscape pattern, landscape ecology, land-use history, habitat quality, invasive species, riparian forest, soil nutrients

Summary

1.	Invasive species are present worldwide, yet predicting which invasive species will become problematic in which ecosystems remains an important ecological challenge. Floodplains are at particular risk for invasion, especially when subjected to anthropogenic disturbance.
2.	We examined how components of flood regime, habitat quality and habitat configuration influenced the presence and abundance of three invasive shrubs in the floodplain of the Wisconsin River. Shrub taxa included two non-natives (Lonicera spp. and Rhamnus spp.) and one native (Zanthoxylum americanum). Observations of taxa presence and abundance were recorded in nine forested river reaches, spanning three physiographic regions. We also compared the productivity of Z. americanum across a flood control levee in one reach.
3.	Physiographic region significantly predicted the presence and abundance of these three taxa, acting as a synthetic indicator of differences in climate, geography and topography. Invasion was greatest in regions where modifications to flood regime and land use were most pronounced. Physiographic region was excluded from subsequent analyses to assess more specific predictors of shrub distributions.
4.	Habitat configuration and quality both predicted shrub taxa presence and abundance. Shrub taxa were most frequently observed and most abundant in small forest patches, near roads, and in sandy soil with low nutrient content. Edge habitats have many of these characteristics. Edges appear to be favoured by avian shrub dispersers and provide conditions suitable for invasive establishment.
5.	Flooding influenced non-native and native invaders differently. Non-native taxa were observed less frequently and at lower abundances in frequently flooded areas, probably because of a sensitivity to flooding. However, the presence, abundance and productivity of the native invader increased with flooding. Anthropogenic modifications to the flood regime limited hydrologic connectivity and may have reduced the competitive advantage of flood-tolerant traits, which allowed the invasion of upland species.
6.	Synthesis. In the floodplain of the Wisconsin River, anthropogenic modifications that created edge habitat and altered flood regime facilitated shrub invasions, whereas unfragmented forest and intact flood regime limited invasion. Large patches of floodplain forest, less regulated flooding regimes, and lower road densities may help reduce the spread of invasive shrubs in temperate floodplains.

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Journal : Neighbourhood models of the effects of the invasive Acer platanoides on tree seedling dynamics: linking impacts on communities and ecosystem

Journal of Ecology

Volume 96 Issue 1 Page 78-90, January 2008

To cite this article: Lorena Gómez-Aparicio, Charles D Canham, Patrick H Martin (2008) Neighbourhood models of the effects of the invasive Acer platanoides on tree seedling dynamics: linking impacts on communities and ecosystems
Journal of Ecology 96 (1) , 78–90 doi:10.1111/j.1365-2745.2007.01317.x

Abstract

Neighbourhood models of the effects of the invasive Acer platanoides on tree seedling dynamics: linking impacts on communities and ecosystems

• Lorena Gómez-Aparicio ^1,2*¹Institute of Ecosystem Studies, PO Box AB, Millbrook, NY 12545–0129, USA; ²Instituto de Recursos Naturales y Agrobiología (IRNAS-CSIC), PO Box 1052, Sevilla 41080, Spain; and *Correspondence author: E-mail: lorenag@irnase.csic.es,
• Charles D. Canham ¹¹Institute of Ecosystem Studies, PO Box AB, Millbrook, NY 12545–0129, USA; and
• Patrick H. Martin ^1,31Institute of Ecosystem Studies, PO Box AB, Millbrook, NY 12545–0129, USA; ³Department of Horticulture and Landscape Architecture, Colorado State University, 1173 Campus Delivery, Fort Collins, CO 80523–1173, USA

• ¹Institute of Ecosystem Studies, PO Box AB, Millbrook, NY 12545–0129, USA; ²Instituto de Recursos Naturales y Agrobiología (IRNAS-CSIC), PO Box 1052, Sevilla 41080, Spain; and ³Department of Horticulture and Landscape Architecture, Colorado State University, 1173 Campus Delivery, Fort Collins, CO 80523–1173, USA

*Correspondence author: E-mail: lorenag@irnase.csic.es

Key-words: Acer platanoides, invasive species, neighbourhood index, plant-soil feedbacks, seedling survival and growth, spatially explicit models, soil fertility, temperate forests

Summary

1.	Effects of invasive species on ecosystem processes are often thought to underlie the effects of invaders on community dynamics. Specifically, positive feedbacks in which invasive species alter ecosystem function in ways that favour their own growth have been suggested as an important mechanism contributing to the success of invasion.
2.	In this study, we analysed the impacts of the invasive exotic tree Acer platanoides on survival and growth of conspecific and native tree seedlings, and explored whether these impacts can be explained by the ecosystem effects of the invader. Seedlings of Acer platanoides, Acer saccharum, Fraxinus americana and Prunus serotina were monitored in quadrats in three forest stands in north-western Connecticut. Soil resources and light levels were quantified in the same quadrats.
3.	Maximum-likelihood methods were used to predict seedling survival and growth as a function of the size and spatial configuration of A. platanoides trees in the immediate neighbourhood (0–25 m).
4.	The abundance of A. platanoides in the neighbourhood had moderate negative effects on survival of first-year conspecific seedlings, but did not affect survival of older conspecific or native seedlings. These negative effects on conspecifics were not correlated with soil nutrients or light levels, but were presumably related to Janzen-Connell effects. In contrast, A. platanoides had strong positive effects on the growth of seedlings of all four species. These positive effects appear to be related to the positive impacts of the invader on soil fertility.
5.	Our results support the importance of canopy-seedling feedbacks as a mechanism regulating the rate of invasion in forests. However, they also indicate that the net consequences of feedbacks on the process of invasion are probably determined by the balance of positive and negative feedbacks acting at the same time on different aspects of regeneration (i.e. survival vs. growth).
6.	Synthesis. Because the species with the highest inherent growth rates were the most responsive to the ‘fertilizing’ effect of A. platanoides, we conclude that the invasion of north-eastern forests by this exotic tree may facilitate canopy dominance by fast-growing native and exotic species associated with fertile soils.

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Journal : Is invasiveness a legacy of evolution? Phylogenetic patterns in the alien flora of Mediterranean islands

Journal of Ecology

Volume 96 Issue 1 Page 46-57, January 2008

To cite this article: Philip W. Lambdon (2008) Is invasiveness a legacy of evolution? Phylogenetic patterns in the alien flora of Mediterranean islands
Journal of Ecology 96 (1) , 46–57 doi:10.1111/j.1365-2745.2007.01324.x

Abstract

Is invasiveness a legacy of evolution? Phylogenetic patterns in the alien flora of Mediterranean islands

• Philip W. Lambdon* *Correspondence and present address: Global Programmes Department, Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire SG19 2DL, UK. E-mail: plambdon@googlemail.com.

• NERC Centre for Ecology and Hydrology, Hill of Brathens, Banchory, Aberdeenshire, AB31 4BW, UK

*Correspondence and present address: Global Programmes Department, Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire SG19 2DL, UK. E-mail: plambdon@googlemail.com.

Key-words: biological invasions, cladistic relationships, macro- vs. microevolution, relatedness measures, screening protocols, taxonomy, trait analysis.

Summary

1.	The Mediterranean region has been invaded by a wide range of introduced plant species which differ greatly in their ecology, morphology and human utilization. In order to identify a suite of traits which characterize invasiveness, recent studies have advocated the use of evolutionary relationships to unravel highly confounded influences.
2.	This study attempts to identify an evolutionary component to invasiveness and other complex invasion-related traits in the Mediterranean alien flora using an autocorrelation technique, the ‘phylogenetic association test’. I compared a traditional hierarchical taxonomy with the recent phylogeny of the Angiosperm Phylogeny Group.
3.	Invasiveness did not have a significant phylogenetic component. Any weak clustering was generally at the genus level.
4.	Several associated ‘meta-traits’ (high introduction frequency, adaptation to several habitat types and favourability for different modes of introduction), exhibited stronger phylogenetic components. Although each of these conveys some of the attributes of invasiveness, their clustering patterns differed considerably, suggesting that they arise from independent evolutionary pressures. Furthermore, within each meta-trait, different clusters may have been selected for different reasons.
5.	Other reasons for the lack of a detectable evolutionary component to invasiveness are discussed. Firstly, the results of our test simulations suggested that incorrect phylogeny could result in a moderate degree of error. Secondly, over evolutionary time, complex or stochastic events such as ecosystem change could radically alter the adaptive advantages of particular traits.
6.	Synthesis. Since invasiveness has little phylogenetic component, I argue that it is less likely to be predictable from as yet unidentified traits in any simple way. Although trait syndromes could develop without leaving a phylogenetic pattern, its absence probably indicates that the dominant selective forces are responses to short-term ecological shifts, and a greater mechanistic understanding of these is needed.

This article is cited by:

• Philip W. Lambdon. Why is habitat breadth correlated strongly with range size? Trends amongst the alien and native floras of Mediterranean islands. Journal of Biogeography doi: 10.1111/j.1365-2699.2008.01894.x
  Abstract Abstract and References Full Text Article Full Article PDF

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Journal : Exotic invasive plant accumulates native soil pathogens which inhibit native plants

Journal of Ecology

Volume 96 Issue 1 Page 58-67, January 2008

To cite this article: Seema Mangla, Inderjit, Ragan M. Callaway (2008) Exotic invasive plant accumulates native soil pathogens which inhibit native plants
Journal of Ecology 96 (1) , 58–67 doi:10.1111/j.1365-2745.2007.01312.x

Abstract

Exotic invasive plant accumulates native soil pathogens which inhibit native plants

• Seema Mangla ¹¹Centre for Environmental Management of Degraded Ecosystems (CEMDE), University of Delhi, Delhi 110007, India; and ,
• Inderjit ¹*¹Centre for Environmental Management of Degraded Ecosystems (CEMDE), University of Delhi, Delhi 110007, India; and *Correspondence author. E-mail: inderjit@cemde.du.ac.in and
• Ragan M. Callaway ²²Organismal Biology and Ecology, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA

• ¹Centre for Environmental Management of Degraded Ecosystems (CEMDE), University of Delhi, Delhi 110007, India; and ²Organismal Biology and Ecology, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA

*Correspondence author. E-mail: inderjit@cemde.du.ac.in

Key-words: allelopathy, Chromolaena odorata, Fusarium, fungal pathogen, indirect interactions, invasion, soil biota, soil pathogen, root leachate

Summary

1.	We investigated the role of a native generalist soil pathogen through which a non-native invasive plant species may suppress naturalized/native plant species.
2.	We found that rhizosphere soils of Chromolaena odorata, one of the world's most destructive tropical invasive weeds, accumulate high concentrations of the generalist soil borne fungi, Fusarium (tentatively identified as F. semitectum), thus creating a negative feedback for native plant species.
3.	Soils collected beneath Chromolaena in the Western Ghats of India inhibited naturalized/native species and contained over 25 times more spores of the pathogenic fungi Fusarium semitectum than soils collected at the same locations beneath neighbouring native species that were at least 20 m from any Chromolaena plant. Sterilization of these soils eliminated their inhibitory effect. Chromolaena root leachate experimentally added to uninvaded soils increased Fusarium spore density by over an order of magnitude, and increased the inhibitory effect of the soils.
4.	The positive effect of Chromolaena root leachates on Fusarium spores was attenuated by activated carbon, suggesting a biochemical basis for how the invader stimulated the pathogen.
5.	Synthesis. Invasive plants have been shown to escape inhibitory soil biota in their native range and to inhibit soil biota in their invaded range, but our results indicate that the impacts of Chromolaena are due to the exacerbation of biotic interactions among native plants and native soil biota, which is to our knowledge a new invasive pathway.

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Journal : Short- and long-term effects of disturbance and propagule pressure on a biological invasion

Journal of Ecology

Volume 96 Issue 1 Page 68-77, January 2008

To cite this article: Kevin H. Britton-Simmons, Karen C. Abbott (2008) Short- and long-term effects of disturbance and propagule pressure on a biological invasion
Journal of Ecology 96 (1) , 68–77 doi:10.1111/j.1365-2745.2007.01319.x

Abstract

Short- and long-term effects of disturbance and propagule pressure on a biological invasion

• Kevin H. Britton-Simmons* *Correspondence and present address. Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA. E-mail: aquaman@u.washington.edu and
• Karen C. Abbott†

• Department of Ecology and Evolution, The University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA

*Correspondence and present address. Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA. E-mail: aquaman@u.washington.edu

Key-words: biological invasion, biotic resistance, disturbance, establishment probability, propagule pressure, Sargassum muticum

†Present address: Department of Zoology, University of Wisconsin, 430 Lincoln Drive, Madison, WI 53706, USA

Summary

1.	Invading species typically need to overcome multiple limiting factors simultaneously in order to become established, and understanding how such factors interact to regulate the invasion process remains a major challenge in ecology.
2.	We used the invasion of marine algal communities by the seaweed Sargassum muticum as a study system to experimentally investigate the independent and interactive effects of disturbance and propagule pressure in the short term. Based on our experimental results, we parameterized an integrodifference equation model, which we used to examine how disturbances created by different benthic herbivores influence the longer term invasion success of S. muticum.
3.	Our experimental results demonstrate that in this system neither disturbance nor propagule input alone was sufficient to maximize invasion success. Rather, the interaction between these processes was critical for understanding how the S. muticum invasion is regulated in the short term.
4.	The model showed that both the size and spatial arrangement of herbivore disturbances had a major impact on how disturbance facilitated the invasion, by jointly determining how much space-limitation was alleviated and how readily disturbed areas could be reached by dispersing propagules.
5.	Synthesis. Both the short-term experiment and the long-term model show that S. muticum invasion success is co-regulated by disturbance and propagule pressure. Our results underscore the importance of considering interactive effects when making predictions about invasion success.

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Journal : A checklist for ecological management of landscapes for conservation

Ecology Letters

Volume 11 Issue 1 Page 78-91, January 2008

To cite this article: David Lindenmayer, Richard J. Hobbs, Rebecca Montague-Drake, Jason Alexandra, Andrew Bennett, Mark Burgman, Peter Cale, Aram Calhoun, Viki Cramer, Peter Cullen, Don Driscoll, Lenore Fahrig, Joern Fischer, Jerry Franklin, Yrjo Haila, Malcolm Hunter, Philip Gibbons, Sam Lake, Gary Luck, Chris MacGregor, Sue McIntyre, Ralph Mac Nally, Adrian Manning, James Miller, Hal Mooney, Reed Noss, Hugh Possingham, Denis Saunders, Fiona Schmiegelow, Michael Scott, Dan Simberloff, Tom Sisk, Gary Tabor, Brian Walker, John Wiens, John Woinarski, Erika Zavaleta (2008) A checklist for ecological management of landscapes for conservation

Ecology Letters 11 (1) , 78–91 doi:10.1111/j.1461-0248.2007.01114.x

Abstract

REVIEW AND SYNTHESIS

A checklist for ecological management of landscapes for conservation

• David Lindenmayer¹*¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia*E-mail: david.lindenmayer@anu.edu.au,
• Richard J. Hobbs²²School of Environmental Science, Murdoch University, Murdoch, Western Australia 6150, Australia,
• Rebecca Montague-Drake¹¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia,
• Jason Alexandra³³Land and Water Australia, Canberra, ACT 2601, Australia,
• Andrew Bennett⁴⁴School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia,
• Mark Burgman⁵⁵Department of Botany, University of Melbourne, Parkville, Victoria 3050, Australia,
• Peter Cale⁶⁶Department for Environment and Heritage, Berri, South Australia 5343, Australia,
• Aram Calhoun⁷⁷Department of Wildlife Ecology, 5755 Nutting Hall University of Maine, Orono, ME 04469, USA,
• Viki Cramer²²School of Environmental Science, Murdoch University, Murdoch, Western Australia 6150, Australia,
• Peter Cullen⁸⁸PO Box 89, Gunning, NSW 2581, Australia,
• Don Driscoll¹¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia,
• Lenore Fahrig⁹⁹Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Canada K1S 5B6,
• Joern Fischer¹¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia,
• Jerry Franklin¹⁰¹⁰College of Forest Resources, Box 352100, University of Washington, Seattle, WA 98195-2100, USA,
• Yrjo Haila¹¹¹¹Department of Regional Studies, 33014 University of Tampere, Tampere, Finland,
• Malcolm Hunter⁷⁷Department of Wildlife Ecology, 5755 Nutting Hall University of Maine, Orono, ME 04469, USA,
• Philip Gibbons¹¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia,
• Sam Lake¹²¹²School of Biological Sciences, Monash University, Victoria 3800, Australia,
• Gary Luck¹³¹³Institute for Land, Water and Society, Charles Sturt University, Albury, NSW 2640, Australia,
• Chris MacGregor¹¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia,
• Sue McIntyre¹⁴¹⁴CSIRO Sustainable Ecosystems, GPO Box 284, Canberra, ACT 2601, Australia,
• Ralph Mac Nally¹⁵¹⁵Australian Centre for Biodiversity: Analysis, Policy and Management, School of Biological Sciences, Monash University, Victoria 3800, Australia,
• Adrian Manning¹¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia,
• James Miller¹⁶¹⁶Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA 50011-3221, USA,
• Hal Mooney¹⁷¹⁷Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA,
• Reed Noss¹⁸¹⁸Department of Biology, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816-2368, USA,
• Hugh Possingham¹⁹¹⁹The Ecology Centre, The University of Queensland, St Lucia, QLD 4072, Australia,
• Denis Saunders²⁰²⁰18 Abernethy Street, Weetangera, ACT 2614, Australia,
• Fiona Schmiegelow²¹²¹Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada,
• Michael Scott²²²²USGS-Idaho Cooperative Fish and Wildlife Research Unit, PO Box 441141, University of Idaho, Moscow, ID 83844-1141, USA,
• Dan Simberloff²³²³Department of Ecology and Evolutionary Biology, 569 Dabney Hall, University of Tennessee, Knoxville, TN 37996, USA,
• Tom Sisk²⁴²⁴Environmental Sciences, PO Box 5694, Northern Arizona University, Flagstaff, AZ 86011-5694, USA,
• Gary Tabor²⁵²⁵Wildlife Conservation Society, Bozeman, MT, USA,
• Brian Walker¹⁵¹⁵Australian Centre for Biodiversity: Analysis, Policy and Management, School of Biological Sciences, Monash University, Victoria 3800, Australia,
• John Wiens²⁶²⁶The Nature Conservancy, 4245 N. Fairfax Drive, Suite 100, Arlington, VA 22203, USA,
• John Woinarski²⁷²⁷Department of Natural Resources, Environment and the Arts, PO Box 496, Palmerston, Northern Territory, Australia and
• Erika Zavaleta²⁸²⁸Environmental Studies Department, University of California-Santa Cruz, CA, USA

• ¹Fenner School of the Environment and Society, The Australian National University, Canberra, ACT 0200, Australia
  ²School of Environmental Science, Murdoch University, Murdoch, Western Australia 6150, Australia
  ³Land and Water Australia, Canberra, ACT 2601, Australia
  ⁴School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia
  ⁵Department of Botany, University of Melbourne, Parkville, Victoria 3050, Australia
  ⁶Department for Environment and Heritage, Berri, South Australia 5343, Australia
  ⁷Department of Wildlife Ecology, 5755 Nutting Hall University of Maine, Orono, ME 04469, USA
  ⁸PO Box 89, Gunning, NSW 2581, Australia
  ⁹Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Canada K1S 5B6
  ¹⁰College of Forest Resources, Box 352100, University of Washington, Seattle, WA 98195-2100, USA
  ¹¹Department of Regional Studies, 33014 University of Tampere, Tampere, Finland
  ¹²School of Biological Sciences, Monash University, Victoria 3800, Australia
  ¹³Institute for Land, Water and Society, Charles Sturt University, Albury, NSW 2640, Australia
  ¹⁴CSIRO Sustainable Ecosystems, GPO Box 284, Canberra, ACT 2601, Australia
  ¹⁵Australian Centre for Biodiversity: Analysis, Policy and Management, School of Biological Sciences, Monash University, Victoria 3800, Australia
  ¹⁶Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA 50011-3221, USA
  ¹⁷Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA
  ¹⁸Department of Biology, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816-2368, USA
  ¹⁹The Ecology Centre, The University of Queensland, St Lucia, QLD 4072, Australia²⁰18 Abernethy Street, Weetangera, ACT 2614, Australia
  ²¹Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
  ²²USGS-Idaho Cooperative Fish and Wildlife Research Unit, PO Box 441141, University of Idaho, Moscow, ID 83844-1141, USA
  ²³Department of Ecology and Evolutionary Biology, 569 Dabney Hall, University of Tennessee, Knoxville, TN 37996, USA
  ²⁴Environmental Sciences, PO Box 5694, Northern Arizona University, Flagstaff, AZ 86011-5694, USA
  ²⁵Wildlife Conservation Society, Bozeman, MT, USA
  ²⁶The Nature Conservancy, 4245 N. Fairfax Drive, Suite 100, Arlington, VA 22203, USA
  ²⁷Department of Natural Resources, Environment and the Arts, PO Box 496, Palmerston, Northern Territory, Australia
  ²⁸Environmental Studies Department, University of California-Santa Cruz, CA, USA

*E-mail: david.lindenmayer@anu.edu.au

Abstract

The management of landscapes for biological conservation and ecologically sustainable natural resource use are crucial global issues. Research for over two decades has resulted in a large literature, yet there is little consensus on the applicability or even the existence of general principles or broad considerations that could guide landscape conservation. We assess six major themes in the ecology and conservation of landscapes. We identify 13 important issues that need to be considered in developing approaches to landscape conservation. They include recognizing the importance of landscape mosaics (including the integration of terrestrial and aquatic areas), recognizing interactions between vegetation cover and vegetation configuration, using an appropriate landscape conceptual model, maintaining the capacity to recover from disturbance and managing landscapes in an adaptive framework. These considerations are influenced by landscape context, species assemblages and management goals and do not translate directly into on-the-ground management guidelines but they should be recognized by researchers and resource managers when developing guidelines for specific cases. Two crucial overarching issues are: (i) a clearly articulated vision for landscape conservation and (ii) quantifiable objectives that offer unambiguous signposts for measuring progress.

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