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Templer PH, Mack MC, Chapin FS, Christenson LM, Compton JE, Crook HD, Currie WS, Curtis CJ, Dail DB, D'Antonio CM, Emmett BA, Epstein HE, Goodale CL, Gundersen P, Hobbie SE, Holland K, Hooper DU, Hungate BA, Lamontagne S, Nadelhoffer KJ, Osenberg CW, Perakis SS, Schleppi P, Schimel J, Schmidt IK, Sommerkorn M, Spoelstra J, Tietema A, Wessel WW, Zak DR. Sinks for nitrogen inputs in terrestrial ecosystems: a meta-analysis of 15N tracer field studies. Ecology 2012; 93:1816-29. [PMID: 22928411 DOI: 10.1890/11-1146.1] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e., total ecosystem 15N recovery in plant and soil pools) across natural systems and N partitioning among ecosystem pools. The greatest recoveries of ecosystem 15N tracer occurred in shrublands (mean, 89.5%) and wetlands (84.8%) followed by forests (74.9%) and grasslands (51.8%). In the short term (< 1 week after 15N tracer application), total ecosystem 15N recovery was negatively correlated with fine-root and soil 15N natural abundance, and organic soil C and N concentration but was positively correlated with mean annual temperature and mineral soil C:N. In the longer term (3-18 months after 15N tracer application), total ecosystem 15N retention was negatively correlated with foliar natural-abundance 15N but was positively correlated with mineral soil C and N concentration and C:N, showing that plant and soil natural-abundance 15N and soil C:N are good indicators of total ecosystem N retention. Foliar N concentration was not significantly related to ecosystem 15N tracer recovery, suggesting that plant N status is not a good predictor of total ecosystem N retention. Because the largest ecosystem sinks for 15N tracer were below ground in forests, shrublands, and grasslands, we conclude that growth enhancement and potential for increased C storage in aboveground biomass from atmospheric N deposition is likely to be modest in these ecosystems. Total ecosystem 15N recovery decreased with N fertilization, with an apparent threshold fertilization rate of 46 kg N x ha(-1) x yr(-1) above which most ecosystems showed net losses of applied 15N tracer in response to N fertilizer addition.
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Drenovsky RE, Grewell BJ, D'Antonio CM, Funk JL, James JJ, Molinari N, Parker IM, Richards CL. A functional trait perspective on plant invasion. ANNALS OF BOTANY 2012; 110:141-53. [PMID: 22589328 PMCID: PMC3380596 DOI: 10.1093/aob/mcs100] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND AND AIMS Global environmental change will affect non-native plant invasions, with profound potential impacts on native plant populations, communities and ecosystems. In this context, we review plant functional traits, particularly those that drive invader abundance (invasiveness) and impacts, as well as the integration of these traits across multiple ecological scales, and as a basis for restoration and management. SCOPE We review the concepts and terminology surrounding functional traits and how functional traits influence processes at the individual level. We explore how phenotypic plasticity may lead to rapid evolution of novel traits facilitating invasiveness in changing environments and then 'scale up' to evaluate the relative importance of demographic traits and their links to invasion rates. We then suggest a functional trait framework for assessing per capita effects and, ultimately, impacts of invasive plants on plant communities and ecosystems. Lastly, we focus on the role of functional trait-based approaches in invasive species management and restoration in the context of rapid, global environmental change. CONCLUSIONS To understand how the abundance and impacts of invasive plants will respond to rapid environmental changes it is essential to link trait-based responses of invaders to changes in community and ecosystem properties. To do so requires a comprehensive effort that considers dynamic environmental controls and a targeted approach to understand key functional traits driving both invader abundance and impacts. If we are to predict future invasions, manage those at hand and use restoration technology to mitigate invasive species impacts, future research must focus on functional traits that promote invasiveness and invader impacts under changing conditions, and integrate major factors driving invasions from individual to ecosystem levels.
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Bowman DMJS, Balch J, Artaxo P, Bond WJ, Cochrane MA, D'Antonio CM, DeFries R, Johnston FH, Keeley JE, Krawchuk MA, Kull CA, Mack M, Moritz MA, Pyne S, Roos CI, Scott AC, Sodhi NS, Swetnam TW, Whittaker R. The human dimension of fire regimes on Earth. JOURNAL OF BIOGEOGRAPHY 2011; 38:2223-2236. [PMID: 22279247 PMCID: PMC3263421 DOI: 10.1111/j.1365-2699.2011.02595.x] [Citation(s) in RCA: 269] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Humans and their ancestors are unique in being a fire-making species, but 'natural' (i.e. independent of humans) fires have an ancient, geological history on Earth. Natural fires have influenced biological evolution and global biogeochemical cycles, making fire integral to the functioning of some biomes. Globally, debate rages about the impact on ecosystems of prehistoric human-set fires, with views ranging from catastrophic to negligible. Understanding of the diversity of human fire regimes on Earth in the past, present and future remains rudimentary. It remains uncertain how humans have caused a departure from 'natural' background levels that vary with climate change. Available evidence shows that modern humans can increase or decrease background levels of natural fire activity by clearing forests, promoting grazing, dispersing plants, altering ignition patterns and actively suppressing fires, thereby causing substantial ecosystem changes and loss of biodiversity. Some of these contemporary fire regimes cause substantial economic disruptions owing to the destruction of infrastructure, degradation of ecosystem services, loss of life, and smoke-related health effects. These episodic disasters help frame negative public attitudes towards landscape fires, despite the need for burning to sustain some ecosystems. Greenhouse gas-induced warming and changes in the hydrological cycle may increase the occurrence of large, severe fires, with potentially significant feedbacks to the Earth system. Improved understanding of human fire regimes demands: (1) better data on past and current human influences on fire regimes to enable global comparative analyses, (2) a greater understanding of different cultural traditions of landscape burning and their positive and negative social, economic and ecological effects, and (3) more realistic representations of anthropogenic fire in global vegetation and climate change models. We provide an historical framework to promote understanding of the development and diversification of fire regimes, covering the pre-human period, human domestication of fire, and the subsequent transition from subsistence agriculture to industrial economies. All of these phases still occur on Earth, providing opportunities for comparative research.
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D'Antonio CM, Hughes RF, Tunison JT. Long-term impacts of invasive grasses and subsequent fire in seasonally dry Hawaiian woodlands. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2011; 21:1617-1628. [PMID: 21830706 DOI: 10.1890/10-0638.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Invasive nonnative grasses have altered the composition of seasonally dry shrublands and woodlands throughout the world. In many areas they coexist with native woody species until fire occurs, after which they become dominant. Yet it is not clear how long their impacts persist in the absence of further fire. We evaluated the long-term impacts of grass invasions and subsequent fire in seasonally dry submontane habitats on Hawai'i, USA. We recensused transects in invaded unburned woodland and woodland that had burned in exotic grass-fueled fires in 1970 and 1987 and had last been censused in 1991. In the unburned woodlands, we found that the dominant understory grass invader, Schizachyrium condensatum, had declined by 40%, while native understory species were abundant and largely unchanged from measurements 17 years ago. In burned woodland, exotic grass cover also declined, but overall values remained high and recruitment of native species was poor. Sites that had converted to exotic grassland after a 1970 fire remained dominated by exotic grasses with no increase in native cover despite 37 years without fire. Grass-dominated sites that had burned twice also showed limited recovery despite 20 years of fire suppression. We found limited evidence for "invasional meltdown": Exotic richness remained low across burned sites, and the dominant species in 1991, Melinis minutiflora, is still dominant today. Twice-burned sites are, however, being invaded by the nitrogen-fixing tree Morella faya, an introduced species with the potential to greatly alter the successional trajectory on young volcanic soils. In summary, despite decades of fire suppression, native species show little recovery in burned Hawaiian woodlands. Thus, burned sites appear to be beyond a threshold for "natural recovery" (e.g., passive restoration).
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Corbin JD, D'Antonio CM. Abundance and productivity mediate invader effects on nitrogen dynamics in a California grassland. Ecosphere 2011. [DOI: 10.1890/es10-00113.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Firn J, Moore JL, MacDougall AS, Borer ET, Seabloom EW, HilleRisLambers J, Harpole WS, Cleland EE, Brown CS, Knops JMH, Prober SM, Pyke DA, Farrell KA, Bakker JD, O'Halloran LR, Adler PB, Collins SL, D'Antonio CM, Crawley MJ, Wolkovich EM, La Pierre KJ, Melbourne BA, Hautier Y, Morgan JW, Leakey ADB, Kay A, McCulley R, Davies KF, Stevens CJ, Chu CJ, Holl KD, Klein JA, Fay PA, Hagenah N, Kirkman KP, Buckley YM. Abundance of introduced species at home predicts abundance away in herbaceous communities. Ecol Lett 2011; 14:274-81. [PMID: 21281419 DOI: 10.1111/j.1461-0248.2010.01584.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.
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Bowman DMJS, Balch JK, Artaxo P, Bond WJ, Carlson JM, Cochrane MA, D'Antonio CM, Defries RS, Doyle JC, Harrison SP, Johnston FH, Keeley JE, Krawchuk MA, Kull CA, Marston JB, Moritz MA, Prentice IC, Roos CI, Scott AC, Swetnam TW, van der Werf GR, Pyne SJ. Fire in the Earth system. Science 2009; 324:481-4. [PMID: 19390038 DOI: 10.1126/science.1163886] [Citation(s) in RCA: 710] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Fire is a worldwide phenomenon that appears in the geological record soon after the appearance of terrestrial plants. Fire influences global ecosystem patterns and processes, including vegetation distribution and structure, the carbon cycle, and climate. Although humans and fire have always coexisted, our capacity to manage fire remains imperfect and may become more difficult in the future as climate change alters fire regimes. This risk is difficult to assess, however, because fires are still poorly represented in global models. Here, we discuss some of the most important issues involved in developing a better understanding of the role of fire in the Earth system.
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DiVittorio CT, Corbin JD, D'Antonio CM. Spatial and temporal patterns of seed dispersal: an important determinant of grassland invasion. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2007; 17:311-6. [PMID: 17489239 DOI: 10.1890/06-0610] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We measured spatial and temporal patterns of seed dispersal and seedling recruitment for 58 species in a grassland community to test whether seed dispersal could predict patterns of invasion after disturbance. For the 12 most abundant grasses, recruitment of native species was dependent on the propagule supply of both native and exotic species. Variability in seed rain on small spatial (1-10 m) and temporal (within season) scales led to qualitative differences in the outcome of disturbance colonization such that native species dominated disturbances when exotic seed supply was low but failed to establish when exotic seed supply was high. Local dispersal and spatial heterogeneity in species composition promoted coexistence of native and exotic species by creating refuges from high exotic seed supply within native dominated patches. Despite this, copious exotic seed production strongly limited recruitment of native species in exotic dominated patches. Most grasslands in California are presently dominated by exotic species, suggesting that competition at the seedling stage is a major barrier to native species restoration.
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Thomsen MA, D'Antonio CM, Suttle KB, Sousa WP. Ecological resistance, seed density and their interactions determine patterns of invasion in a California coastal grassland. Ecol Lett 2006; 9:160-70. [PMID: 16958881 DOI: 10.1111/j.1461-0248.2005.00857.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Relatively little experimental evidence is available regarding how ecological resistance and propagule density interact in their effects on the establishment of invasive exotic species. We examined the independent and interactive effects of neighbour cover (biotic resistance), winter vs. spring water addition (abiotic resistance) and seed density on the invasion of the European perennial grass Holcus lanatus into a California coastal grassland dominated by exotic annual grasses. We found that decreased competition from resident exotic grasses had no effect. In contrast, increased late-season water availability eroded the abiotic resistance offered by naturally dry conditions, facilitating invasion. Finally, watering treatment and seed density interacted strongly in determining seedling survival: while seedling mortality was close to 100% in ambient and winter water addition plots, survivor numbers increased with seed density in spring-watered plots. Thus, decreased abiotic resistance can amplify the effect of increased propagule density on seedling establishment, thereby increasing the likelihood of invasion.
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Thomsen MA, D'Antonio CM. Mechanisms of resistance to invasion in a California grassland: the roles of competitor identity, resource availability, and environmental gradients. OIKOS 2006. [DOI: 10.1111/j.2006.0030-1299.14929.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Corbin JD, Thomsen MA, Dawson TE, D'Antonio CM. Summer water use by California coastal prairie grasses: fog, drought, and community composition. Oecologia 2005; 145:511-21. [PMID: 16001220 DOI: 10.1007/s00442-005-0152-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Accepted: 05/03/2005] [Indexed: 10/25/2022]
Abstract
Plants in the Mediterranean climate region of California typically experience summer drought conditions, but correlations between zones of frequent coastal fog inundation and certain species' distributions suggest that water inputs from fog may influence species composition in coastal habitats. We sampled the stable H and O isotope ratios of water in non-photosynthetic plant tissue from a variety of perennial grass species and soil in four sites in northern California in order to determine the proportion of water deriving from winter rains and fog during the summer. The relationship between H and O stable isotopes from our sample sites fell to the right of the local meteoric water line (LMWL) during the summer drought, providing evidence that evaporation of water from the soil had taken place prior to the uptake of water by vegetation. We developed a novel method to infer the isotope values of water before it was subjected to evaporation in which we used experimental data to calculate the slope of the deltaH versus deltaO line versus the LMWL. After accounting for evaporation, we then used a two-source mixing model to evaluate plant usage of fog water. The model indicated that 28-66% of the water taken up by plants via roots during the summer drought came from fog rather than residual soil water from winter rain. Fog use decreased as distance from the coast increased, and there were significant differences among species in the use of fog. Rather than consistent differences in fog use by species whose distributions are limited to the coast versus those with broader distributions, species responded individualistically to summer fog. We conclude that fogwater inputs can mitigate the summer drought in coastal California for many species, likely giving an advantage to species that can use it over species that cannot.
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Corbin JD, D'Antonio CM. COMPETITION BETWEEN NATIVE PERENNIAL AND EXOTIC ANNUAL GRASSES: IMPLICATIONS FOR AN HISTORICAL INVASION. Ecology 2004. [DOI: 10.1890/02-0744] [Citation(s) in RCA: 299] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Corbin JD, D'Antonio CM. Can Carbon Addition Increase Competitiveness of Native Grasses? A Case Study from California. Restor Ecol 2004. [DOI: 10.1111/j.1061-2971.2004.00299.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Alexander JM, D'Antonio CM. Seed Bank Dynamics of French Broom in Coastal California Grasslands: Effects of Stand Age and Prescribed Burning on Control and Restoration. Restor Ecol 2003. [DOI: 10.1046/j.1526-100x.2003.00169.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Levine JM, Vilà M, D'Antonio CM, Dukes JS, Grigulis K, Lavorel S. Mechanisms underlying the impacts of exotic plant invasions. Proc Biol Sci 2003; 270:775-81. [PMID: 12737654 PMCID: PMC1691311 DOI: 10.1098/rspb.2003.2327] [Citation(s) in RCA: 638] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Although the impacts of exotic plant invasions on community structure and ecosystem processes are well appreciated, the pathways or mechanisms that underlie these impacts are poorly understood. Better exploration of these processes is essential to understanding why exotic plants impact only certain systems, and why only some invaders have large impacts. Here, we review over 150 studies to evaluate the mechanisms underlying the impacts of exotic plant invasions on plant and animal community structure, nutrient cycling, hydrology and fire regimes. We find that, while numerous studies have examined the impacts of invasions on plant diversity and composition, less than 5% test whether these effects arise through competition, allelopathy, alteration of ecosystem variables or other processes. Nonetheless, competition was often hypothesized, and nearly all studies competing native and alien plants against each other found strong competitive effects of exotic species. In contrast to studies of the impacts on plant community structure and higher trophic levels, research examining impacts on nitrogen cycling, hydrology and fire regimes is generally highly mechanistic, often motivated by specific invader traits. We encourage future studies that link impacts on community structure to ecosystem processes, and relate the controls over invasibility to the controls over impact.
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Barger NN, D'Antonio CM, Ghneim T, Brink K, Cuevas E. Nutrient Limitation to Primary Productivity in a Secondary Savanna in Venezuela1. Biotropica 2002. [DOI: 10.1111/j.1744-7429.2002.tb00569.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bauer KM, Berlow EL, D'Antonio CM. The Relationship between Climate and Rothrock Sagebrush Colonization Patterns. ACTA ACUST UNITED AC 2002. [DOI: 10.2307/4004006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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D'Antonio CM, Hughes RF, Vitousek PM. Factors Influencing Dynamics of Two Invasive C 4 Grasses in Seasonally Dry Hawaiian Woodlands. Ecology 2001. [DOI: 10.2307/2680088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Richardson DM, Allsopp N, D'Antonio CM, Milton SJ, Rejmánek M. Plant invasions--the role of mutualisms. Biol Rev Camb Philos Soc 2000; 75:65-93. [PMID: 10740893 DOI: 10.1017/s0006323199005435] [Citation(s) in RCA: 554] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Many introduced plant species rely on mutualisms in their new habitats to overcome barriers to establishment and to become naturalized and, in some cases, invasive. Mutualisms involving animal-mediated pollination and seed dispersal, and symbioses between plant roots and microbiota often facilitate invasions. The spread of many alien plants, particularly woody ones, depends on pollinator mutualisms. Most alien plants are well served by generalist pollinators (insects and birds), and pollinator limitation does not appear to be a major barrier for the spread of introduced plants (special conditions relating to Ficus and orchids are described). Seeds of many of the most notorious plant invaders are dispersed by animals, mainly birds and mammals. Our review supports the view that tightly coevolved, plant-vertebrate seed dispersal systems are extremely rare. Vertebrate-dispersed plants are generally not limited reproductively by the lack of dispersers. Most mycorrhizal plants form associations with arbuscular mycorrhizal fungi which, because of their low specificity, do not seem to play a major role in facilitating or hindering plant invasions (except possibly on remote islands such as the Galapagos which are poor in arbuscular mycorrhizal fungi). The lack of symbionts has, however, been a major barrier for many ectomycorrhizal plants, notably for Pinus spp. in parts of the southern hemisphere. The roles of nitrogen-fixing associations between legumes and rhizobia and between actinorhizal plants and Frankia spp. in promoting or hindering invasions have been virtually ignored in the invasions literature. Symbionts required to induce nitrogen fixation in many plants are extremely widespread, but intentional introductions of symbionts have altered the invasibility of many, if not most, systems. Some of the world's worst invasive alien species only invaded after the introduction of symbionts. Mutualisms in the new environment sometimes re-unite the same species that form partnerships in the native range of the plant. Very often, however, different species are involved, emphasizing the diffuse nature of many (most) mutualisms. Mutualisms in new habitats usually duplicate functions or strategies that exist in the natural range of the plant. Occasionally, mutualisms forge totally novel combinations, with profound implications for the behaviour of the introduced plant in the new environment (examples are seed dispersal mutualisms involving wind-dispersed pines and cockatoos in Australia; and mycorrhizal associations involving plant roots and fungi). Many ecosystems are becoming more susceptible to invasion by introduced plants because: (a) they contain an increasing array of potential mutualistic partners (e.g. generalist frugivores and pollinators, mycorrhizal fungi with wide host ranges, rhizobia strains with infectivity across genera); and (b) conditions conductive for the establishment of various alien/alien synergisms are becoming more abundant. Incorporating perspectives on mutualisms in screening protocols will improve (but not perfect) our ability to predict whether a given plant species could invade a particular habitat.
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Levine JM, D'Antonio CM. Elton Revisited: A Review of Evidence Linking Diversity and Invasibility. OIKOS 1999. [DOI: 10.2307/3546992] [Citation(s) in RCA: 916] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Weber E, D'Antonio CM. Germination and growth responses of hybridizing Carpobrotus species (Aizoaceae) from coastal California to soil salinity. AMERICAN JOURNAL OF BOTANY 1999; 86:1257-1263. [PMID: 10487813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Germination, growth, and physiological responses of hybridizing Carpobrotus from coastal California to soil salinity were studied. Hybrids are presumably the result of hybridization and introgression between the exotic Carpobrotus edulis, a succulent perennial invading coastal habitats, and the native or long-naturalized C. chilensis. Germination responses were investigated at 0, 10, 20, and 50% seawater. Seedling growth and physiology were compared by irrigating seedlings with solutions of the same seawater concentrations and in low and high nutrients. Germination was inhibited in the presence of salt, but recovered after transferring the seeds to fresh water. Seeds exposed to salt had higher final germination rates than control. Growth of Carpobrotus was slightly enhanced by low seawater concentrations but reduced at high salinity at both nutrient regimes. Leaf cell sap osmolarity increased with increasing soil salinity, and taxa did not differ significantly in this physiological adjustment. Leaf carbon isotope ratios (∂(13)C) ranged from -28 to -22‰ and became less negative at higher salinities, indicating an improved water use efficiency in the seedlings at high salt concentrations. In addition, ∂(13)C values were generally less negative at high than at low nutrients. Differences among taxa were generally small. The results show that salinity affects both establishment and growth of hybridizing Carpobrotus. The overall weak species differences in salt tolerance indicate that the exotic C. edulis can occupy the same sites as C. chilensis in terms of salinity. The similarity of hybrids in their response to salinity suggests that they may contribute to the invasion by Carpobrotus.
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Ewel JJ, O'Dowd DJ, Bergelson J, Daehler CC, D'Antonio CM, Gómez LD, Gordon DR, Hobbs RJ, Holt A, Hopper KR, Hughes CE, LaHart M, Leakey RRB, Lee WG, Loope LL, Lorence DH, Louda SM, Lugo AE, McEvoy PB, Richardson DM, Vitousek PM. Deliberate Introductions of Species: Research Needs. Bioscience 1999. [DOI: 10.2307/1313438] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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