Structuring evidence for invasional meltdown: broad support but with biases and gaps

Biological Invasions, Journal Year: 2017, Volume and Issue: 20(4), P. 923 - 936

Published: Oct. 14, 2017

Negative interactions have been suggested as a major barrier for species arriving in new habitat. More recently, positive drew attention from community assembly theory and invasion science. The invasional meltdown hypothesis (IMH) introduced the idea that among non-native could facilitate one another's invasion, even increasing their impact upon native community. Many studies addressed IMH, but with contrasting results, reflecting various types of evidence on multitude scales. Here we use hierarchy-of-hypotheses (HoH) approach to differentiate key aspects organizing linking empirical sub-hypotheses IMH. We also assess level support each sub-hypothesis based reported studies. identified 150 addressing majority comes different aims questions. Supporting at or ecosystem are currently rare. Evidence is scarce marine habitats vertebrates. Few questioned by more than 50% evaluated studies, indicating do not affect other's survival, growth, reproduction, abundance, density biomass reciprocal A ↔ B interactions. With HoH IMH presented here, can monitor progress tests evidences For instance, needed, these necessary address core this hypothesis.

Language: Английский

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Development of a Worldwide Consortium on Evolutionary Participatory Breeding in Quinoa

Frontiers in Plant Science, Journal Year: 2016, Volume and Issue: 7

Published: May 9, 2016

Chenopodium quinoa is gaining global importance due to its excellent protein quality and tolerance of abiotic stresses. The last 60 years have seen major strides in the expansion crop production experimentation. Quinoa's wide genetic diversity has led agronomic versatility adaptation different soil types, particularly saline soils, environments with extremely variable conditions terms humidity, altitude, temperature. potential contribute food security was recognized 2013 declaration International Year Quinoa (IYQ). Promoting use improved homogeneous varieties standardized comply applicable norms on seeds or suited intensified conventional agriculture farming systems may not generate necessary resilience needed respond current future challenges. Maintaining increasing biodiversity imperative, as dynamics constitute a threat farmers if spread generated narrow base. In this article, we propose that method evolutionary participatory breeding could be useful tool develop new material cooperation farmers. We introduce preliminary results population development Pacific Northwest region USA. conclude collaborative network (GCN-Quinoa) baseline for plant programs originating developing developed countries meet needs across range physical environments.

Language: Английский

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Competitive ability, stress tolerance and plant interactions along stress gradients

Ecology, Journal Year: 2018, Volume and Issue: 99(4), P. 848 - 857

Published: Jan. 18, 2018

Abstract Exceptions to the generality of stress‐gradient hypothesis ( SGH ) may be reconciled by considering species‐specific traits and stress tolerance strategies. Studies have tested competitive ability in mediating interaction outcomes, but few incorporated this predict how species interactions shift between competition facilitation along gradients. We used field surveys, salt experiments develop a predictive model interspecific shifts across salinity Field survey greenhouse tests revealed tradeoffs ability. Modeling showed that gradients, (1) plant shifted from at high salinities within physiological limits salt‐intolerant plants, (2) collapsed when exceeded (3) neighbor removal overestimate including intraspecific effects. A community‐level experiment, suggested are benign and, facilitative harsh condition, fuzzy under medium environmental due niche differences weak amelioration, works on strong not so confusion arises it is applied questionable Our study clarifies vary Moving forward, focusing applications rather than exceptions or nonexistent gradients would most productive.

Language: Английский

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Ecological mechanisms underlying aridity thresholds in global drylands

Functional Ecology, Journal Year: 2021, Volume and Issue: 36(1), P. 4 - 23

Published: Oct. 30, 2021

Abstract With ongoing climate change, the probability of crossing environmental thresholds promoting abrupt changes in ecosystem structure and functioning is higher than ever. In drylands (areas where it rains <65% what could be potentially evaporated), recent research has shown how three aridity [at (1‐Aridity Index) values 0.54, 0.70 0.80] leads to on structural functional attributes. Despite importance these findings their implications develop effective monitoring adaptation actions combat change desertification, we lack a proper understanding mechanisms unleashing shifts. Here review multiple that may explain existence observed across global drylands, discuss potential amplification underpin hypothetical temporal shifts with change. We propose each threshold caused by different specific mechanisms. The first mainly physiological plant water shortages. second unleashed involving soil processes plant–soil interactions such as erosion, community nutrient cycling circulation. collapse vegetation once third (0.8) crossed related survival limits plants cause sudden cover diversity losses plant–atmospheric feedbacks link further aridification. By identifying, revising linking relevant observed, provide set hypotheses identify knowledge gaps concerning study emergence drylands. were also able establish plausible factors are context dependent influence occurrence time. Our help focus future efforts strategies monitor, adapt or even revert A free Plain Language Summary can found within Supporting Information this article.

Language: Английский

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Neighbourhood diversity mitigates drought impacts on tree growth

Journal of Ecology, Journal Year: 2020, Volume and Issue: 108(3), P. 865 - 875

Published: Jan. 8, 2020

Abstract Biodiversity is considered to mitigate detrimental impacts of climate change on the functioning forest ecosystems, such as drought‐induced decline in productivity. However, previous studies produced controversial results and experimental evidence rare. Specifically, biological mechanisms underlying mitigation effects remain unclear, existing work focuses biodiversity related community scale. Using trait‐based neighbourhood models, we quantified changes above‐ground wood productivity 3,397 trees that were planted a large‐scale tree diversity experiment subtropical China across gradients climatic conditions over 6‐year period. This approach allowed us simultaneously assess what extent functional traits focal at local scale mediate growth response individual drought events. We found species richness can for young trees. Overall, positive net strongest during increased with increasing taxonomic neighbours. In particular, drought‐sensitive (i.e. those low cavitation resistance) benefitted most from growing diverse neighbourhoods, suggesting soil water partitioning among neighbours particularly facilitated vulnerable individuals. Thus, neighbourhoods may enhance ecosystem resistance by locally supporting community. Synthesis . Our findings demonstrate operating are key component regulating forests responses improve insights into how interactions vary along stress highly communities.

Language: Английский

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Plant interaction networks reveal the limits of our understanding of diversity maintenance

Ecology Letters, Journal Year: 2024, Volume and Issue: 27(2)

Published: Feb. 1, 2024

Species interactions are key drivers of biodiversity and ecosystem stability. Current theoretical frameworks for understanding the role make many assumptions which unfortunately, do not always hold in natural, diverse communities. This mismatch extends to annual plants, a common model system studying coexistence, where typically averaged across environmental conditions transitive competitive hierarchies assumed dominate. We quantify interaction networks community wildflowers Western Australia natural shade gradient at local scales. Whilst competition dominated, intraspecific interspecific facilitation were widespread all categories. Interaction strengths directions varied substantially despite close spatial proximity similar levels species richness, with most interacting different ways under conditions. Contrary expectations, predominantly intransitive. These findings encourage us rethink how we conceive categorize mechanisms driving plant systems.

Language: Английский

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Influence of soil microbiota in nurse plant systems

Functional Ecology, Journal Year: 2015, Volume and Issue: 30(1), P. 30 - 40

Published: Oct. 27, 2015

Summary Facilitation by nurse plants is a key process involved in the organization of plant communities and maintenance biodiversity, particularly harsh environments. Nurse increase diversity productivity these ecosystems, but our knowledge on mechanisms through which such facilitation operates still expanding. Despite growing evidence that soil microbiota impact fitness community dynamics, their role has been little explored. Here, we synthesize available effect abundance, composition activity microbial communities, beneficiary species. Studies conducted mostly arid semi‐arid systems show promote development differentiated characterized higher abundance activity, dominance competitive bacteria larger mycorrhizal networks, compared to gaps coexisting non‐nurses. There also associated with positive effects establishment, growth species, although remain unclear. We suggest they include increased nutrient availability for plants, better use resources functional complementarity community, stabilization direct molecular signalling between microbes affect defence interactions. Evidence as mediators growing, there are too few studies draw generalizable conclusions. Future needed assess ontogeny environmental conditions under other determine groups specific plants.

Language: Английский

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SGH: stress or strain gradient hypothesis? Insights from an elevation gradient on the roof of the world

Annals of Botany, Journal Year: 2017, Volume and Issue: 120(1), P. 29 - 38

Published: March 13, 2017

Background and Aims The stress gradient hypothesis (SGH), the view that competition prevails in undisturbed productive environments, shifts to facilitation disturbed or stressful has become a central paradigm ecology. However, an alternative proposes relationship between biotic interactions environmental severity should be unimodal instead of monotonic. Possible causes discrepancies these two views were examined high elevation desert arid Trans-Himalayas. Methods A putative nurse species its associated plant community was surveyed over entire range, spanning from alpine vegetation belts. results analysed at level (vegetation cover richness), considering distinction intensity importance interactions. Interactions (pairwise interactions) also considered, i.e. variation within niche species, for which abundance (species cover) probability occurrence (presence/absence) most widespread along distinguished. Key Results Overall, infrequent our study system; however, it observed species. At level, showed pattern. departure prediction SGH happened abruptly where entered belt lowest elevation. This abrupt shift attributed turnover with contrasting tolerances. increased consistently as increases individuals deviate their optimum (increasing strain). Conclusion While not supported strain hypothesis, how perceive ambient optimum, provided parsimonious explanation outcome plant–plant both scales.

Language: Английский

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Spatial and temporal aridity gradients provide poor proxies for plant–plant interactions under climate change: a large‐scale experiment

Functional Ecology, Journal Year: 2015, Volume and Issue: 30(1), P. 20 - 29

Published: Nov. 3, 2015

Summary Plant–plant interactions may critically modify the impact of climate change on plant communities. However, magnitude and even direction potential future remains highly debated, especially for water‐limited ecosystems. Predictions range from increasing facilitation to competition with aridification. The different methodologies used assessing plant–plant under changing environmental conditions affect outcome but they are not equally represented in literature. Mechanistic experimental manipulations rare compared correlative approaches that infer patterns current observations along spatial climatic gradients. Here, we utilize a unique gradient combination large‐scale, long‐term experiment test whether predictions about yield similar results when using manipulations, gradients or temporal variation. We assessed shrub–annual three sites natural rainfall (spatial) during 9 years varying (temporal) 8 dry wet ambient (experimental) closely mimicked regional scenarios. were fundamentally among all approaches. Experimental water hardly altered shrub effects annual communities fitness parameters biomass survival. Along gradient, shifted clearly negative mildly facilitative towards drier sites, whereas variation showed opposite trend: more years. Based our approach, conclude interaction will remain change. In contrast, commonly applied space‐for‐time approach based would have suggested discuss mechanisms governing differences Our study highlights critical importance evaluating impacts. Correlative approaches, example gradients, be misleading overestimate response

Language: Английский

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Ecology and evolution of facilitation among symbionts

Nature Communications, Journal Year: 2018, Volume and Issue: 9(1)

Published: Nov. 13, 2018

Facilitation occurs when one species positively impacts the fitness of another, and has predominantly been studied in free-living like plants. can also occur among symbiont (mutualistic or parasitic) strains, but equivalent studies are scarce. To advance an integrated view effect facilitation on ecology evolution, we review empirical evidence their underlying mechanisms, explore factors favouring its emergence, discuss consequences for virulence transmission. We argue that concept improve understanding evolutionary forces shaping communities effects hosts.

Language: Английский

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