Ericoid mycorrhizal colonization and associated fungal communities along a wetland gradient in the Acadian forest of Eastern Canada

2022 ◽  
Vol 56 ◽  
pp. 101138
Author(s):  
Amanda Griffin ◽  
Gavin Kernaghan
Keyword(s):  
Mycorrhizal Colonization ◽  
Fungal Communities ◽  
Eastern Canada ◽  
Acadian Forest

Soil P reduces mycorrhizal colonization while favors fungal pathogens: observational and experimental evidence in Bipinnula (Orchidaceae)

2020 ◽  
Vol 96 (11) ◽  
Author(s):  
María Isabel Mujica ◽  
María Fernanda Pérez ◽  
Marcin Jakalski ◽  
Florent Martos ◽  
Marc André Selosse
Keyword(s):  
Mycorrhizal Fungi ◽  
Fungal Pathogens ◽  
Large Population ◽  
Mycorrhizal Colonization ◽  
Fungal Communities ◽  
Soil Conditions ◽  
Short Term ◽  
Soil P ◽  
Orchid Mycorrhizal Fungi ◽  
P Addition

ABSTRACT Little is known about the soil factors influencing root-associated fungal communities in Orchidaceae. Limited evidence suggests that soil nutrients may modulate the association with orchid mycorrhizal fungi (OMF), but their influence on non-mycorrhizal fungi remains unexplored. To study how nutrient availability affects mycorrhizal and non-mycorrhizal fungi associated with the orchid Bipinnula fimbriata, we conducted a metagenomic investigation within a large population with variable soil conditions. Additionally, we tested the effect of phosphorus (P) addition on fungal communities and mycorrhizal colonization. Soil P negatively correlated with the abundance of OMF, but not with the abundance of non-mycorrhizal fungi. After fertilization, increments in soil P negatively affected mycorrhizal colonization; however, they had no effect on OMF richness or composition. The abundance and richness of pathotrophs were negatively related to mycorrhizal colonization and then, after fertilization, the decrease in mycorrhizal colonization correlated with an increase in pathogen richness. Our results suggest that OMF are affected by soil conditions differently from non-mycorrhizal fungi. Bipinnula fimbriata responds to fertilization by altering mycorrhizal colonization rather than by switching OMF partners in the short term, and the influence of nutrients on OMF is coupled with indirect effects on the whole fungal community and potentially on plant's health.

Borealization of the New England – Acadian Forest: a review of the evidence

2020 ◽  
Vol 28 (3) ◽  
pp. 284-293
Author(s):  
Josh Noseworthy ◽  
Thomas M. Beckley
Keyword(s):  
New England ◽  
Scientific Journal ◽  
Landscape Scale ◽  
Forest Composition ◽  
Ecological Communities ◽  
Eastern Canada ◽  
Ample Evidence ◽  
Anthropogenic Fire ◽  
European Settlement ◽  
Acadian Forest

The New England – Acadian Forest (NEAF) is an ecoregion spanning 24 million hectares of the northeastern United States and eastern Canada. The region is characterized as a transitional forest naturally composed of both boreal and temperate species. The term “borealization” is sometimes used to describe various processes driving the NEAF toward a more boreal character at the expense of its temperate forest species and ecological communities. That the NEAF has undergone significant landscape-scale change in the last four centuries since European settlement is well understood. The purpose of this manuscript is to review the literature on the forest composition and dynamics of this region to investigate whether past, current, and (or) predicted future processes of change are indeed driving the forest toward a more boreal character. We examine studies on the historical forest composition and impacts of past and current land-use practices, as well as indirect anthropogenic changes that are predicted to influence future forest compositions of the NEAF. We review over 100 peer-reviewed scientific journal articles and government reports related to this issue. We find ample evidence to suggest that, at the landscape scale, there has been widespread replacement of temperate tree species by boreal species since European settlement. Five primary drivers have facilitated borealization across the NEAF: logging and high-grading, natural reforestation of abandoned farmland, industrial clearcutting, anthropogenic fire, and boreal conifer plantations. Furthermore, the borealization of the NEAF has continued to occur in direct contrast to the predicted impacts of climate change. We encourage future scholarship to tackle these aspects of borealization in the NEAF, including its social, economic, and ecological implications.

scholarly journals Survey of Arbuscular Mycorrhizal Fungal Communities in Northern California Vineyards and Mycorrhizal Colonization Potential of Grapevine Nursery Stock

HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1702-1706 ◽  
Author(s):  
Xiaomei Cheng ◽  
Kendra Baumgartner
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Common Species ◽  
Mycorrhizal Colonization ◽  
Fungal Communities ◽  
Fungal Colonization ◽  
Northern California ◽  
Nursery Stock ◽  
Low Phosphorus ◽  
Colonization Potential

Indigenous arbuscular mycorrhizal (AM) fungal communities were characterized by examining spores in five fumigated and five nonfumigated vineyards in Northern California. None of the vineyards surveyed lacked spores, but species composition differed among the vineyards. Most of the fungi were in the genus Glomus; Paraglomus occultum Morton & Redecker, G. etunicatum Becker & Gerd., and G. aggregatum Schenck & Smith emend. Koske were the most common species identified. Fungal diversity was greater in nonfumigated than in fumigated vineyards. Field-propagated grapevine nursery stock was examined as a potential source of AM fungi for fumigated vineyards. We quantified fungal colonization of new roots initiated from field-grown benchgrafts and potted benchgrafts of Cabernet Sauvignon on three rootstocks (101-14, 110R, and St. George). After 7 months of growth in the greenhouse, new roots initiated from dormant roots of field-grown and potted benchgrafts were colonized by AM fungi. Mycorrhizal colonization of new roots of field-grown benchgrafts was significantly higher than that of potted benchgrafts. Our results suggest that field-propagated nursery stock can serve as a source of AM fungi and may be better suited for fumigated and/or low phosphorus soils than potted benchgrafts.

Incidence of beech bark disease resistance in the eastern Acadian forest of North America

2013 ◽  
Vol 89 (05) ◽  
pp. 690-695 ◽  
Author(s):  
Anthony R. Taylor ◽  
Donnie A. McPhee ◽  
Judy A. Loo
Keyword(s):  
North America ◽  
Prince Edward Island ◽  
Geographical Area ◽  
Fagus Grandifolia ◽  
Natural Resistance ◽  
Beech Bark Disease ◽  
Eastern Canada ◽  
Average Percentage ◽  
Acadian Forest ◽  
Disease Free

Beech bark disease (BBD) is a fatal affliction of American beech (Fagus grandifolia Ehrh.) in North America. Although natural resistance to BBD has been observed, reports vary with respect to incidence of resistance, with 1% being most commonly acknowledged. In this paper, we provide the first formal, empirical estimate of BBD resistance over a wide geographical area where BBD has been prevalent for longest in North America. We conducted our study in the Acadian Forest region of eastern Canada. Thirty-five beech-dominated stands (>5 ha each) were surveyed across the provinces of New Brunswick, Nova Scotia, and Prince Edward Island, spanning a time since infection (TSI) period between 1890 and 1975. Stands were surveyed for incidence of disease-free beech trees, which was used as a proxy for BBD resistance. Across our study area, the average percentage of disease-free trees observed was 3.3%; however, the occurrence of disease-free trees varied significantly geographically, with the oldest, most southerly TSI zone indicating 2.2% and the youngest, most northerly TSI zone showing 5.7%. Although geographic variation of disease-free beech trees may reflect disease exposure time, we speculate that lower minimum winter temperatures, combined with less intensive land-use history are the underlying mechanisms that explain the higher observed percentage of disease-free trees in the most northerly TSI zones.

Experimentally altered rainfall regimes and host root traits affect grassland arbuscular mycorrhizal fungal communities

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Suzanne Donn ◽  
Sally Power ◽  
Kirk Barnett ◽  
Jeff Powell
Keyword(s):  
Fungal Community ◽  
Community Assembly ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Rainfall Regime ◽  
Precipitation Regimes ◽  
Rainfall Regimes

Future climate scenarios predict changes in rainfall regimes. These changes are expected to affect plants via effects on the expression of root traits associated with water and nutrient uptake. Associated microorganisms may also respond to these new precipitation regimes, either directly in response to changes in the soil environment or indirectly in response to altered root trait expression. We characterised arbuscular mycorrhizal (AM) fungal communities in an Australian grassland exposed to experimentally altered rainfall regimes. We used Illumina sequencing to assess the responses of AM fungal communities associated with four plant species sampled in different watering treatments and evaluated the extent to which shifts were associated with changes in root traits. We observed that altered rainfall regimes affected the composition but not the richness of the AM fungal communities, and we found distinctive communities in the increased rainfall treatment. We found no evidence of altered rainfall regime effects via changes in host physiology because none of the studied traits were affected by changes in rainfall. However, specific root length was observed to correlate with AM fungal richness, while concentrations of phosphorus and calcium in root tissue and the proportion of root length allocated to fine roots were correlated to community composition. Our study provides evidence that climate change and its effects on rainfall may influence AM fungal community assembly, as do plant traits related to plant nutrition and water uptake. We did not find evidence that host responses to altered rainfall drive AM fungal community assembly in this grassland ecosystem.

Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Temporal Dynamics ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Plant Responses ◽  
Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

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