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Berthelot S, Bauhus J, Dormann CF, Gravel D, Messier C, Nock CA, Paquette A, Reich PB, Fründ J. Exotic tree species have consistently lower herbivore load in a cross-Atlantic tree biodiversity experiment. Ecology 2023:e4070. [PMID: 37127925 DOI: 10.1002/ecy.4070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 03/02/2023] [Accepted: 03/14/2023] [Indexed: 05/03/2023]
Abstract
It is commonly expected that exotic plants experience reduced herbivory, but experimental evidence for such enemy release is still controversial. One reason for conflicting results might be that community context has rarely been accounted for, although the surrounding plant diversity may moderate enemy release. Here, we tested the effects of focal tree origin and surrounding tree diversity on herbivore abundance and leaf damage in a cross-Atlantic tree diversity experiment in Canada and Germany. We evaluated six European tree species paired with six North American congeners in both their native and exotic range, expecting lower herbivory for the exotic tree species in each pair at each site. Such reciprocal experiments have long been called for, but have not been realized thus far. In addition to a thorough evaluation of overall enemy release effects, we tested whether enemy release effects change with the surrounding tree diversity. Herbivore abundance was indeed consistently lower on exotics across all six tree genera (12 comparisons). This effect of exotic status was independent of continent, phylogenetic relatedness and surrounding tree diversity. In contrast, leaf damage associated with generalist leaf chewers was consistently higher on North American tree species. Interestingly, several species of European weevils were the most abundant leaf chewers on both continents and the dominant herbivores at the Canadian site. Thus, most observed leaf damage likely reflects the effect of generalist herbivores that feed heavily on plant species they have not evolved with. At the German site, sap-suckers were the dominant herbivores and showed a pattern consistent with enemy release. Taken together, the consistently lower herbivory on exotics on both continents is not purely a pattern of enemy release in the strict sense, but to some degree additionally reflects the susceptibility of native plants to invasive herbivores. In conclusion, our cross-Atlantic study is consistent with the idea that non-native trees have generally reduced herbivory, regardless of tree community diversity and species identity, but for different reasons depending on the dominant herbivore guild.
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Affiliation(s)
- Sylvie Berthelot
- Albert-Ludwigs-Universität Freiburg, Biometry and Environmental System Analysis, Tennenbacher Straße 4, Freiburg, Germany
| | - Jürgen Bauhus
- Albert-Ludwigs-Universität Freiburg, Chair of Silviculture, Tennenbacher Straße 4, Freiburg, Germany
| | - Carsten F Dormann
- Albert-Ludwigs-Universität Freiburg, Biometry and Environmental System Analysis, Tennenbacher Straße 4, Freiburg, Germany
| | - Dominique Gravel
- Département de Biologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Christian Messier
- Département des Sciences Naturelles and Institut des Sciences de la Forêt Tempérée (ISFORT), Université du Québec en Outaouais (UQO), Ripon, QC, Canada
- Centre d'étude de la Forêt, Université du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Charles A Nock
- University of Alberta, Department of Renewable Resources, Earth and Atmospheric Sciences Building, Edmonton, AB, Canada
| | - Alain Paquette
- Centre d'étude de la Forêt, Université du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Institute for Global Change Biology, University of Michigan, Ann Arbor, MI
| | - Jochen Fründ
- Albert-Ludwigs-Universität Freiburg, Biometry and Environmental System Analysis, Tennenbacher Straße 4, Freiburg, Germany
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2
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Hajek P, Link RM, Nock CA, Bauhus J, Gebauer T, Gessler A, Kovach K, Messier C, Paquette A, Saurer M, Scherer-Lorenzen M, Rose L, Schuldt B. Mutually inclusive mechanisms of drought-induced tree mortality. Glob Chang Biol 2022; 28:3365-3378. [PMID: 35246895 DOI: 10.1111/gcb.16146] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Unprecedented tree dieback across Central Europe caused by recent global change-type drought events highlights the need for a better mechanistic understanding of drought-induced tree mortality. Although numerous physiological risk factors have been identified, the importance of two principal mechanisms, hydraulic failure and carbon starvation, is still debated. It further remains largely unresolved how the local neighborhood composition affects individual mortality risk. We studied 9435 young trees of 12 temperate species planted in a diversity experiment in 2013 to assess how hydraulic traits, carbon dynamics, pest infestation, tree height and neighborhood competition influence individual mortality risk. Following the most extreme global change-type drought since record in 2018, one third of these trees died. Across species, hydraulic safety margins (HSMs) were negatively and a shift towards a higher sugar fraction in the non-structural carbohydrate (NSC) pool positively associated with mortality risk. Moreover, trees infested by bark beetles had a higher mortality risk, and taller trees a lower mortality risk. Most neighborhood interactions were beneficial, although neighborhood effects were highly species-specific. Species that suffered more from drought, especially Larix spp. and Betula spp., tended to increase the survival probability of their neighbors and vice versa. While severe tissue dehydration marks the final stage of drought-induced tree mortality, we show that hydraulic failure is interrelated with a series of other, mutually inclusive processes. These include shifts in NSC pools driven by osmotic adjustment and/or starch depletion as well as pest infestation and are modulated by the size and species identity of a tree and its neighbors. A more holistic view that accounts for multiple causes of drought-induced tree mortality is required to improve predictions of trends in global forest dynamics and to identify mutually beneficial species combinations.
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Affiliation(s)
- Peter Hajek
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Roman M Link
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
| | - Charles A Nock
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Freiburg, Germany
| | - Tobias Gebauer
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
- ETH Zurich, Institute of Terrestrial Ecosystems, Zurich, Switzerland
| | - Kyle Kovach
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Christian Messier
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
- University of Quebec in Outaouais (UQO), Institut des Sciences de la Forêt Tempérée (ISFORT), Gatineau, Quebec, Canada
| | - Alain Paquette
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | | | - Laura Rose
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Bernhard Schuldt
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
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3
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Hajek P, Link RM, Nock CA, Bauhus J, Gebauer T, Gessler A, Kovach K, Messier C, Paquette A, Saurer M, Scherer-Lorenzen M, Rose L, Schuldt B. Mutually inclusive mechanisms of drought-induced tree mortality. Glob Chang Biol 2022; 28:3365-3378. [PMID: 35246895 DOI: 10.1101/2020.12.17.423038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/16/2021] [Indexed: 05/22/2023]
Abstract
Unprecedented tree dieback across Central Europe caused by recent global change-type drought events highlights the need for a better mechanistic understanding of drought-induced tree mortality. Although numerous physiological risk factors have been identified, the importance of two principal mechanisms, hydraulic failure and carbon starvation, is still debated. It further remains largely unresolved how the local neighborhood composition affects individual mortality risk. We studied 9435 young trees of 12 temperate species planted in a diversity experiment in 2013 to assess how hydraulic traits, carbon dynamics, pest infestation, tree height and neighborhood competition influence individual mortality risk. Following the most extreme global change-type drought since record in 2018, one third of these trees died. Across species, hydraulic safety margins (HSMs) were negatively and a shift towards a higher sugar fraction in the non-structural carbohydrate (NSC) pool positively associated with mortality risk. Moreover, trees infested by bark beetles had a higher mortality risk, and taller trees a lower mortality risk. Most neighborhood interactions were beneficial, although neighborhood effects were highly species-specific. Species that suffered more from drought, especially Larix spp. and Betula spp., tended to increase the survival probability of their neighbors and vice versa. While severe tissue dehydration marks the final stage of drought-induced tree mortality, we show that hydraulic failure is interrelated with a series of other, mutually inclusive processes. These include shifts in NSC pools driven by osmotic adjustment and/or starch depletion as well as pest infestation and are modulated by the size and species identity of a tree and its neighbors. A more holistic view that accounts for multiple causes of drought-induced tree mortality is required to improve predictions of trends in global forest dynamics and to identify mutually beneficial species combinations.
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Affiliation(s)
- Peter Hajek
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Roman M Link
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
| | - Charles A Nock
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Freiburg, Germany
| | - Tobias Gebauer
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
- ETH Zurich, Institute of Terrestrial Ecosystems, Zurich, Switzerland
| | - Kyle Kovach
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Christian Messier
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
- University of Quebec in Outaouais (UQO), Institut des Sciences de la Forêt Tempérée (ISFORT), Gatineau, Quebec, Canada
| | - Alain Paquette
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | | | - Laura Rose
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Bernhard Schuldt
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
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4
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Urgoiti J, Messier C, Keeton WS, Reich PB, Gravel D, Paquette A. No complementarity no gain-Net diversity effects on tree productivity occur once complementarity emerges during early stand development. Ecol Lett 2022; 25:851-862. [PMID: 35106898 DOI: 10.1111/ele.13959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 11/22/2021] [Accepted: 12/09/2021] [Indexed: 12/21/2022]
Abstract
Although there is compelling evidence that tree diversity has an overall positive effect on forest productivity, there are important divergences among studies on the nature and strength of these diversity effects and their timing during forest stand development. To clarify conflicting results related to stand developmental stage, we explored how diversity effects on productivity change through time in a diversity experiment spanning 11 years. We show that the strength of diversity effects on productivity progressively increases through time, becoming significantly positive after 9 years. Moreover, we demonstrate that the strengthening of diversity effects is driven primarily by gradual increases in complementarity. We also show that mixing species with contrasting resource-acquisition strategies, and the dominance of deciduous, fast-developing species, promote positive diversity effects on productivity. Our results suggest that the canopy closure and subsequent stem exclusion phase are key for promoting niche complementarity in diverse tree communities.
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Affiliation(s)
- Jon Urgoiti
- Centre for Forest Research, Université du Québec à Montréal, Montréal, Québec, Canada
| | - Christian Messier
- Centre for Forest Research, Université du Québec à Montréal, Montréal, Québec, Canada.,Institut des sciences de la forêt tempérée (ISFORT), Université du Québec en Outaouais (UQO), Ripon, Québec, Canada
| | - William S Keeton
- Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia.,Institute for Global Change Biology, and School for the Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
| | - Dominique Gravel
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Alain Paquette
- Centre for Forest Research, Université du Québec à Montréal, Montréal, Québec, Canada
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5
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Martin‐Guay M, Belluau M, Côté B, Handa IT, Jewell MD, Khlifa R, Munson AD, Rivest M, Whalen JK, Rivest D. Tree identity and diversity directly affect soil moisture and temperature but not soil carbon ten years after planting. Ecol Evol 2022; 12:e8509. [PMID: 35136558 PMCID: PMC8809433 DOI: 10.1002/ece3.8509] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 12/01/2021] [Accepted: 12/16/2021] [Indexed: 01/05/2023] Open
Abstract
Soil C is the largest C pool in forest ecosystems that contributes to C sequestration and mitigates climate change. Tree diversity enhances forest productivity, so diversifying the tree species composition, notably in managed forests, could increase the quantity of organic matter being transferred to soils and alter other soil properties relevant to the C cycle.A ten-year-old tree diversity experiment was used to study the effects of tree identity and diversity (functional and taxonomic) on soils. Surface (0-10 cm) mineral soil was repeatedly measured for soil C concentration, C:N ratio, pH, moisture, and temperature in twenty-four tree species mixtures and twelve corresponding monocultures (replicated in four blocks).Soil pH, moisture, and temperature responded to tree diversity and identity. Greater productivity in above- and below-ground tree components did not increase soil C concentration. Soil pH increased and soil moisture decreased with functional diversity, more specifically, when species had different growth strategies and shade tolerances. Functional identity affected soil moisture and temperature, such that tree communities with more slow-growing and shade-tolerant species had greater soil moisture and temperature. Higher temperature was measured in communities with broadleaf-deciduous species compared to communities with coniferous-evergreen species.We conclude that long-term soil C cycling in forest plantations will likely respond to changes in soil pH, moisture, and temperature that is mediated by tree species composition, since tree species affect these soil properties through their litter quality, water uptake, and physical control of soil microclimates.
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Affiliation(s)
- Marc‐Olivier Martin‐Guay
- Institut des Sciences de la Forêt Tempérée (ISFORT)Université du Québec en Outaouais (UQO)RiponQuebecCanada
| | - Michaël Belluau
- Département des Sciences BiologiquesUniversité du Québec à Montréal (UQÀM)MontréalQuebecCanada
| | - Benoit Côté
- Department of Natural Resource Sciences (NRS)McGill UniversityMontréalQuebecCanada
| | - Ira Tanya Handa
- Département des Sciences BiologiquesUniversité du Québec à Montréal (UQÀM)MontréalQuebecCanada
| | - Mark D. Jewell
- Department of BiologyMcGill UniversityMontréalQuebecCanada
| | - Rim Khlifa
- Département Science et TechnologieUniversité TÉLUQMontréalQuebecCanada
| | - Alison D. Munson
- Département des Sciences du Bois et de la ForêtUniversité LavalQuébecQuebecCanada
| | - Maxime Rivest
- Department of BiologyMcGill UniversityMontréalQuebecCanada
| | - Joann K. Whalen
- Department of Natural Resource Sciences (NRS)McGill UniversityMontréalQuebecCanada
| | - David Rivest
- Institut des Sciences de la Forêt Tempérée (ISFORT)Université du Québec en Outaouais (UQO)RiponQuebecCanada
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6
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Williams LJ, Butler EE, Cavender-Bares J, Stefanski A, Rice KE, Messier C, Paquette A, Reich PB. Enhanced light interception and light use efficiency explain overyielding in young tree communities. Ecol Lett 2021; 24:996-1006. [PMID: 33657676 DOI: 10.1111/ele.13717] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/05/2020] [Accepted: 02/10/2021] [Indexed: 01/13/2023]
Abstract
Diverse plant communities are often more productive than mono-specific ones. Several possible mechanisms underlie this phenomenon but their relative importance remains unknown. Here we investigated whether light interception alone or in combination with light use efficiency (LUE) of dominant and subordinate species explained greater productivity of mixtures relative to monocultures (i.e. overyielding) in 108 young experimental tree communities. We found mixed-species communities that intercepted more light than their corresponding monocultures had 84% probability of overyielding. Enhanced LUE, which arose via several pathways, also mattered: the probability of overyielding was 71% when, in a mixture, species with higher 'inherent' LUE (i.e. LUE in monoculture) intercepted more light than species with lower LUE; 94% when dominant species increased their LUE in mixture; and 79% when subordinate species increased their LUE. Our results suggest that greater light interception and greater LUE, generated by inter and intraspecific variation, together drive overyielding in mixed-species forests.
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Affiliation(s)
- Laura J Williams
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA.,Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Ethan E Butler
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
| | - Jeannine Cavender-Bares
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Artur Stefanski
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA
| | - Karen E Rice
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA.,Extension Education, University of Florida, Fort Lauderdale, FL, 33314, USA
| | - Christian Messier
- Centre for Forest Research, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada.,Institut des sciences de la forêt tempérée, Université du Québec en Outaouais, Ripon, QC, J0V 1V0, Canada
| | - Alain Paquette
- Centre for Forest Research, Université du Québec à Montréal, Montréal, QC, H3C 3P8, Canada
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St Paul, MN, 55108, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, 2753, Australia
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7
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Grossman JJ, Butterfield AJ, Cavender-Bares J, Hobbie SE, Reich PB, Gutknecht J, Kennedy PG. Non-symbiotic soil microbes are more strongly influenced by altered tree biodiversity than arbuscular mycorrhizal fungi during initial forest establishment. FEMS Microbiol Ecol 2019; 95:5553462. [PMID: 31437281 DOI: 10.1093/femsec/fiz134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/21/2019] [Indexed: 11/13/2022] Open
Abstract
While the relationship between plant and microbial diversity has been well studied in grasslands, less is known about similar relationships in forests, especially for obligately symbiotic arbuscular mycorrhizal (AM) fungi. To assess the effect of varying tree diversity on microbial alpha- and beta-diversity, we sampled soil from plots in a high-density tree diversity experiment in Minnesota, USA, 3 years after establishment. About 3 of 12 tree species are AM hosts; the other 9 primarily associate with ectomycorrhizal fungi. We used phospho- and neutral lipid fatty acid analysis to characterize the biomass and functional identity of the whole soil bacterial and fungal community and high throughput sequencing to identify the species-level richness and composition of the AM fungal community. We found that plots of differing tree composition had different bacterial and fungal communities; plots with conifers, and especially Juniperus virginiana, had lower densities of several bacterial groups. In contrast, plots with a higher density or diversity of AM hosts showed no sign of greater AM fungal abundance or diversity. Our results indicate that early responses to plant diversity vary considerably across microbial groups, with AM fungal communities potentially requiring longer timescales to respond to changes in host tree diversity.
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Affiliation(s)
- Jake J Grossman
- Arnold Arboretum, Harvard University, 1300 Centre St., Boston, MA 02131, USA.,Department of Ecology, Evolution, and Behavior, University of Minnesota -- Twin Cities, 1475 Gortner Ave., St. Paul, MN, 55108, USA
| | - Allen J Butterfield
- Department of Chemical Engeineering, University of Minnesota -- Duluth, 1303 Ordean Ct., Duluth, MN 55812, USA
| | - Jeannine Cavender-Bares
- Department of Ecology, Evolution, and Behavior, University of Minnesota -- Twin Cities, 1475 Gortner Ave., St. Paul, MN, 55108, USA
| | - Sarah E Hobbie
- Department of Ecology, Evolution, and Behavior, University of Minnesota -- Twin Cities, 1475 Gortner Ave., St. Paul, MN, 55108, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota -- Twin Cities, 1530 Cleveland Ave. N., St. Paul, MN 55108, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith 2751, NSW, Australia
| | - Jessica Gutknecht
- Department of Soil, Water, and Climate, University of Minnesota --Twin Cities, 1991 Upper Buford Circle, St. Paul, MN 55108, USA
| | - Peter G Kennedy
- Department of Plant and Microbial Biology, University of Minnesota -- Twin Cities, 1475 Gortner Ave., St. Paul, MN 55108, USA
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8
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Archambault C, Paquette A, Messier C, Khlifa R, Munson AD, Handa IT. Evergreenness influences fine root growth more than tree diversity in a common garden experiment. Oecologia 2019; 189:1027-39. [PMID: 30850886 DOI: 10.1007/s00442-019-04373-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 02/26/2019] [Indexed: 10/27/2022]
Abstract
Recent studies have reported positive net diversity effects on aboveground tree growth. However, whether similar effects occur belowground through root investment, and whether such effects are related to evergreenness of tree communities, is less clear. Here we studied vertical distribution of standing fine root biomass of twelve North American temperate tree species planted in a common garden tree diversity experiment of varying species richness and evergreenness to test whether belowground niche complementarity of trees could explain positive diversity effects reported aboveground. We tested two alternative hypotheses: trees in mixtures increase uptake of soil resources (1) by increasing vertical root stratification and/or producing a greater fine root density (mg cm-3) or (2) by producing similar or fewer fine roots that are potentially more efficient. Additionally, we hypothesized that proportional allocation to belowground biomass increases with evergreenness of tree communities. Fine roots were sampled in six layers of 5-10 cm, from 0 to 40 cm depth in single-, two- and four-species mixtures. We did not observe an effect of species richness on rooting depth or root density, refuting the hypothesis that aboveground overyielding in tree mixtures is linked to fine root overyielding. Rather, we observed a significant negative diversity effect (- 7.6%) on total fine root density, suggesting overall less investment to fine roots with increasing diversity. The strong positive effect of evergreeness on proportional allocation to fine roots over aboveground parts suggests that deciduous tree roots may be generally more efficient at absorbing soil resources, at least in the early years after tree establishment.
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9
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Grossman JJ, Cavender-Bares J, Hobbie SE, Reich PB, Montgomery RA. Species richness and traits predict overyielding in stem growth in an early-successional tree diversity experiment. Ecology 2018; 98:2601-2614. [PMID: 28727905 DOI: 10.1002/ecy.1958] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/03/2017] [Accepted: 07/10/2017] [Indexed: 11/07/2022]
Abstract
Over the last two decades, empirical work has established that higher biodiversity can lead to greater primary productivity; however, the importance of different aspects of biodiversity in contributing to such relationships is rarely elucidated. We assessed the relative importance of species richness, phylogenetic diversity, functional diversity, and identity of neighbors for stem growth 3 yr after seedling establishment in a tree diversity experiment in eastern Minnesota. Generally, we found that community-weighted means of key functional traits (including mycorrhizal association, leaf nitrogen and calcium, and waterlogging tolerance) as well as species richness were strong, independent predictors of stem biomass growth. More phylogenetically diverse communities did not consistently produce more biomass than expected, and the trait values or diversity of individual functional traits better predicted biomass production than did a multidimensional functional diversity metric. Furthermore, functional traits and species richness best predicted growth at the whole-plot level (12 m2 ), whereas neighborhood composition best predicted growth at the focal tree level (0.25 m2 ). The observed effects of biodiversity on growth appear strongly driven by positive complementary effects rather than by species-specific selection effects, suggesting that synergistic species' interactions rather than the influence of a few important species may drive overyielding.
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Affiliation(s)
- Jake J Grossman
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, 140 Gortner Laboratory, 1479 Gortner Ave., St. Paul, Minnesota, 55108, USA
| | - Jeannine Cavender-Bares
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, 140 Gortner Laboratory, 1479 Gortner Ave., St. Paul, Minnesota, 55108, USA
| | - Sarah E Hobbie
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Twin Cities, 140 Gortner Laboratory, 1479 Gortner Ave., St. Paul, Minnesota, 55108, USA
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, Twin Cities, 115 Green Hall, 1530 Cleveland Ave. N., St. Paul, Minnesota, 55108, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, New South Wales, Australia
| | - Rebecca A Montgomery
- Department of Forest Resources, University of Minnesota, Twin Cities, 115 Green Hall, 1530 Cleveland Ave. N., St. Paul, Minnesota, 55108, USA
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10
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Raymond-Léonard LJ, Gravel D, Reich PB, Handa IT. Springtail community structure is influenced by functional traits but not biogeographic origin of leaf litter in soils of novel forest ecosystems. Proc Biol Sci 2018; 285:rspb.2018.0647. [PMID: 29848651 DOI: 10.1098/rspb.2018.0647] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 04/30/2018] [Indexed: 11/12/2022] Open
Abstract
With ongoing global change, shifts in the ranges of non-native species and resulting novel communities can modify biotic interactions and ecosystem processes. We hypothesized that traits and not biogeographic origin of novel plant communities will determine community structure of organisms that depend on plants for habitat or as a food resource. We tested the functional redundancy of novel tree communities by verifying if six pairs of congeneric European and North American tree species bearing similar leaf litter traits resulted in similar ecological filters influencing the assembly of springtail (Collembola) communities at two sites. Litter biogeographic origin (native versus non-native) did not influence springtail community structure, but litter genus, which generally reflected trait differences, did. Our empirical evidence suggests that a functional trait approach may be indeed as relevant as, and complementary to, studying biogeographic origin to understand the ecological consequences of non-native tree species in soils of novel forest ecosystems.
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Affiliation(s)
- Laura J Raymond-Léonard
- Département des sciences biologiques, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada
| | - Dominique Gravel
- Département de biologie, Université de Sherbrooke, Sherbrooke, Quebec JIK 2R1, Canada
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, USA.,Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2753, Australia
| | - I Tanya Handa
- Département des sciences biologiques, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada
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Khlifa R, Paquette A, Messier C, Reich PB, Munson AD. Do temperate tree species diversity and identity influence soil microbial community function and composition? Ecol Evol 2017; 7:7965-7974. [PMID: 29043048 PMCID: PMC5632628 DOI: 10.1002/ece3.3313] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/07/2017] [Accepted: 07/15/2017] [Indexed: 01/02/2023] Open
Abstract
Studies of biodiversity–ecosystem function in treed ecosystems have generally focused on aboveground functions. This study investigates intertrophic links between tree diversity and soil microbial community function and composition. We examined how microbial communities in surface mineral soil responded to experimental gradients of tree species richness (SR), functional diversity (FD), community‐weighted mean trait value (CWM), and tree identity. The site was a 4‐year‐old common garden experiment near Montreal, Canada, consisting of deciduous and evergreen tree species mixtures. Microbial community composition, community‐level physiological profiles, and respiration were evaluated using phospholipid fatty acid (PLFA) analysis and the MicroResp™ system, respectively. The relationship between tree species richness and glucose‐induced respiration (GIR), basal respiration (BR), metabolic quotient (qCO2) followed a positive but saturating shape. Microbial communities associated with species mixtures were more active (basal respiration [BR]), with higher biomass (glucose‐induced respiration [GIR]), and used a greater number of carbon sources than monocultures. Communities associated with deciduous tree species used a greater number of carbon sources than those associated with evergreen species, suggesting a greater soil carbon storage capacity. There were no differences in microbial composition (PLFA) between monocultures and SR mixtures. The FD and the CWM of several functional traits affected both BR and GIR. In general, the CWM of traits had stronger effects than did FD, suggesting that certain traits of dominant species have more effect on ecosystem processes than does FD. Both the functions of GIR and BR were positively related to aboveground tree community productivity. Both tree diversity (SR) and identity (species and functional identity—leaf habit) affected soil microbial community respiration, biomass, and composition. For the first time, we identified functional traits related to life‐history strategy, as well as root traits that influence another trophic level, soil microbial community function, via effects on BR and GIR.
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Affiliation(s)
- Rim Khlifa
- Centre d'étude de la forêt Département des sciences du bois et de la forêt Faculté de foresterie, de géographie et de géomatique Université Laval Québec QC Canada
| | - Alain Paquette
- Centre d'étude de la forêt Université du Québec à Montréal Montréal QC Canada
| | - Christian Messier
- Centre d'étude de la forêt Université du Québec à Montréal Montréal QC Canada.,Institut des sciences de la forêt feuillue tempérée (ISFORT) Université du Québec en Outaouais Ripon QC Canada
| | - Peter B Reich
- Department of Forest Resources University of Minnesota St. Paul MN USA.,Hawkesbury Institute for the Environment University of Western Sydney Penrith NSW Australia
| | - Alison D Munson
- Centre d'étude de la forêt Département des sciences du bois et de la forêt Faculté de foresterie, de géographie et de géomatique Université Laval Québec QC Canada
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