Mycorrhizal chronosequence near Exit Glacier, Alaska

1996 ◽  
Vol 74 (9) ◽  
pp. 1496-1506 ◽  
Author(s):  
D.J. Helm ◽  
E.B. Allen ◽  
J.M. Trappe
Keyword(s):  
Mycorrhizal Fungi ◽  
Woody Plants ◽  
Arbuscular Mycorrhizae ◽  
Mineral Soil ◽  
Picea Sitchensis ◽  
Populus Balsamifera ◽  
Black Cottonwood ◽  
Third Stage ◽  
Successional Stages ◽  
Time Required

Mycorrhizal fungi associated with plant species may change as vegetation develops following disturbance. The objectives of this study were to compare ectomycorrhizae through a chronosequence on deglaciated land from bare mineral soil to mature forest and to determine time required for mycorrhizal formation on natural seedlings. A chronosequence that formed as Exit Glacier retreated enabled us to document changes in mycorrhizae on existing woody plants, including Populus balsamifera ssp. trichocarpa (Torr. & Gray) Hult, (black cottonwood) that dominates the early stages, Alnus sinuata (Regel) Rydb. (Sitka alder) that has few ectomycorrhizal fungal associates, and Picea sitchensis (Bong.) Carr. (Sitka spruce) that typifies late successional stages. Some seedlings of Populus balsamifera became ectomycorrhizal within 3 weeks of germination but most took longer. Although a dark type without clamp connections dominated willows in the second and third stage, it was not a dominant in the first stage and was rare on 1st year seedlings. Ectomycorrhizal types differed among successional stages for Populus balsamifera. Diversity increased from early successional stages to later stages, mostly from an increase in evenness rather than richness. Arbuscular mycorrhizae were not found on any woody plants, although a few herbaceous plants had low infection percentages. Keywords: ectomycorrhizae, chronosequence, Populus, Alnus, Picea, Salix.

scholarly journals Succession of arbuscular mycorrhizal fungi in a deflation hollow of the Słowiński National Park, Poland

2014 ◽  
Vol 69 (3) ◽  
pp. 223-236 ◽  
Author(s):  
Mariusz Tadych ◽  
Janusz Błaszkowski
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Glomus Aggregatum ◽  
Organic C ◽  
Spore Abundance ◽  
Successional Stages ◽  
Amf Communities ◽  
Stage 1

In the years 1994-1995, the occurrence of arbuscular mycorrhizal fungi (AMF) and arbuscular mycorrhizae (AM) in eight successional stages of vegetation of a deflation hollow no. 12 of the Łeba Bar, Poland, was investigated. Early successional stages were colonized by members of the families Gramineae and Juncaceae, being gradually replaced by ericaceous plants in the middle and later stages and by trees in the most advanced stage corresponding to the <em>Empetro nigri-Pinetum</em> plant association. From the 96 soil samples collected, 21 species in three genera of AMF were recovered. The fungi most frequently found were members of the genus <em>Acaulospora</em>. The overall spore abundance, the species_ richness of AMF and the level of AM colonisation increased from stage 1 to reach a maximum in the middle stages and then gradually declined, being lowest in the forested stage 8. The values of the overall spore abundance and those of the abundances of the most frequently occurring AMF species strongly evidenced functioning in nature of the process of host-dependent differentiation of AMF communities. Of the five most numerously represented AMF species, the early colonizer and quickly diminishing in later successional stages was <em>Glomus</em> 107. The mid-late successor was <em>A. koskei</em>, and the latest - <em>Glomus aggregatum</em>. All measures of AMF presence negatively correlated with the content of organic C in the soil and most of them were negatively correlated with soil N-NO3 and P concentrations. In contrast, the occurrence of AMY and AM generally was positively correlated with soil pH and the K content of the soil.

scholarly journals Using Discrete-Point LiDAR to Classify Tree Species in the Riparian Pacific Northwest, USA

2021 ◽  
Vol 13 (14) ◽  
pp. 2647
Author(s):  
Julia Tatum ◽  
David Wallin
Keyword(s):  
Pacific Northwest ◽  
Tree Species ◽  
3D Structure ◽  
Alnus Rubra ◽  
Populus Balsamifera ◽  
Segmentation Method ◽  
Black Cottonwood ◽  
Riparian Landscape ◽  
Individual Trees ◽  
Species Mapping

Practical methods for tree species identification are important for both land management and scientific inquiry. LiDAR has been widely used for species mapping due to its ability to characterize 3D structure, but in structurally complex Pacific Northwest forests, additional research is needed. To address this need and to determine the feasibility of species modeling in such forests, we compared six approaches using five algorithms available in R’s lidR package and Trimble’s eCognition software to determine which approach most consistently identified individual trees across a heterogenous riparian landscape. We then classified segments into Douglas fir (Pseudotsuga menziesii), black cottonwood (Populus balsamifera ssp. trichocarpa), and red alder (Alnus rubra). Classification accuracies based on the best-performing segmentation method were 91%, 92%, and 84%, respectively. To our knowledge, this is the first study to investigate tree species modeling from LiDAR in a natural Pacific Northwest forest, and the first to model Pacific Northwest species at the landscape scale. Our results suggest that LiDAR alone may provide enough information on tree species to be useful to land managers in limited applications, even under structurally challenging conditions. With slight changes to the modeling approach, even higher accuracies may be possible.

Studies on the life-history of Bunostomum phlebotomum (Railliet, 1900), a hookworm parasite of cattle

Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent
Keyword(s):  
Infective Larva ◽  
Stage Larva ◽  
Fourth Stage ◽  
Larval Stages ◽  
The Third ◽  
Third Stage ◽  
History Of ◽  
Time Required ◽  
Cutaneous Blood ◽  
Fourth Stage Larva

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.

scholarly journals Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil

2011 ◽  
Vol 42 (3) ◽  
pp. 859-867 ◽  
Author(s):  
Graziella S Gattai ◽  
Sônia V Pereira ◽  
Cynthia M. C Costa ◽  
Cláudia E. P Lima ◽  
Leonor C Maia
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Microbial Activity ◽  
Contaminated Soil ◽  
Mycorrhizal Fungi ◽  
Woody Plants ◽  
Arbuscular Mycorrhizal

scholarly journals Occurrence of arbuscular mycorrhizal fungi in soils of early stages of a secondary succession of Atlantic Forest in South Brazil

2006 ◽  
Vol 20 (3) ◽  
pp. 513-521 ◽  
Author(s):  
Sidney Luiz Stürmer ◽  
Osmar Klauberg Filho ◽  
Maike Hering de Queiroz ◽  
Margarida Matos de Mendonça
Keyword(s):  
Species Richness ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Secondary Succession ◽  
Arbuscular Mycorrhizal ◽  
Plant Species Richness ◽  
Atlantic Rain Forest ◽  
Inoculum Potential ◽  
Mycorrhizal Inoculum Potential ◽  
Successional Stages

Arbuscular mycorrhizal fungi (AMF) species diversity and mycorrhizal inoculum potential were assessed in areas representative of stages of secondary succession in the Brazilian Atlantic Rain Forest. Within each stage - pioneer, 'capoeirinha' and 'capoeirão'- four transects were established and three soil samples were taken along each transect. The plant community was dominated by Pteridium aquilinium in the pioneer stage, while Dodonaea viscosa and P. aquilinium were co-dominants in the 'capoeirinha' stage. In capoeirão, Miconia cinnamomifolia was dominant followed by Euterpe edulis. Total spore number per 100 g soil was significantly larger in the 'capoeirinha' stage than in the other stages, although the number of viable spores was similar among stages. Acaulosporaceae and Glomeraceae were the predominant families accounting for 83% of the total spores recovered. Of the 18 spore morphotypes, 10 were allocated to known species, with Acaulospora sp. and Glomus sp. being the dominants recovered in all samples. Simpson's index of diversity and evenness for AMF species were not significantly different among the successional stages and AMF species richness was negatively correlated with plant species richness. Soil from 'Capoeirinha" showed the highest inoculum potential (37%). Dominance of the mycorrhizal community by few sporulators and the relationship between plant and fungal diversity are discussed.

scholarly journals POST PARTUM HEMORRHAGE;

2017 ◽  
Vol 24 (09) ◽  
pp. 1347-1353
Author(s):  
Sardar Alfareed Zafar ◽  
Asim Shaukat ◽  
Ayesha Khalid ◽  
Ammara Niaz ◽  
Shagufta Noor
Keyword(s):  
Medical Therapy ◽  
Post Partum ◽  
Young Patients ◽  
Reproductive Capacity ◽  
Cross Sectional ◽  
Vaginal Deliveries ◽  
Future Fertility ◽  
Third Stage ◽  
Conventional Medical Therapy ◽  
Time Required

Primary postpartum hemorrhagic, rightly called as obstetrician’s nightmare,refers to excessive blood loss of more than 500ml during the third stage of labour or in the first24 hours after delivery. It continues to be one of the leading causes of maternal mortality andmorbidity all over the world including Pakistan where it is responsible for 21-31% of maternalmortality and morbidity. Objectives: Objective of study was to determine the efficacy of balloontamponade in the management of primary PPH, so that a low cast, easy to use technology isavailable for conserving future fertility by treating postpartum hemorrhage. Settings: Departmentof Gynae & Obs, Allied Hospital, Faisalabad. Study Design: Descriptive cross sectional study.Study Period: 6 months from 1st Oct, 2015 to 31st March, 2016. Material & Methods: All patientsdelivered vaginally at term (after 37 completed weeks of gestation) who developed PPH due touterine atony after failure of conventional medical therapy were included in this study. Patientselection was based on inclusion and exclusion criteria. Their demographic profile and efficacyof balloon tamponade was checked in terms of time required to control hemorrahage andneed of laparotomy. Results: During study period total no. Of vaginal deliveries were 3000.Out of these 298 developed PPH, 220 had PPH due to uterine atony and did not respond toconventional medical therapy. The age of patients ranged between 22 and 40 years with meanage of 30 year (±4.88SD). The parity of the patients ranged between 1 and 14 with the meanparity of 4 (±2.26SD). The condom catheter was introduced in all the selected 80 patients andwas successful in 73 patients. Conclusions: In developing countries such as Pakistan wherethe maternal death rate from PPH is very high, this safe, in expensive and easy procedure (itdoes not require any expertise) can be applied in any situation to save a life and to save theuterus in young patients to conserve reproductive capacity and prevent them from surgery andits morbidity. This will protect the patients from irreversible shock and even death with a successrate of 85-95%.

Arbuscular mycorrhizae of American ginseng (Panax quinquefolius) in cultivated field plots: plant age affects the development of a colonization lag phase

1999 ◽  
Vol 77 (7) ◽  
pp. 1028-1034 ◽  
Author(s):  
T P McGonigle ◽  
J P Hovius ◽  
R L Peterson
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Dry Mass ◽  
American Ginseng ◽  
Panax Quinquefolius ◽  
Root Turnover ◽  
Lag Phase ◽  
Seed Collection ◽  
Second Year ◽  
Hyphal Coils

Temporal patterns of colonization of roots of perennials by arbuscular mycorrhizal fungi are poorly understood because annual crops are more often studied. The objective was to monitor in detail the growth and mycorrhizae of the perennial American ginseng (Panax quinquefolius L.) over the first 2 years after seeding. In particular, the extent of carry-over of colonization into the second year was examined. Delayed germination of some seeds caused by chance-driven variability in the time needed for seed maturation after seed collection provided an opportunity to compare first- and second-year plants under identical conditions in the second year. For all plants, development of arbuscules rose to a maximum in mid-August, falling partially thereafter. Production of hyphal coils proceeded more slowly but steadily, so that end-of-season colonization was composed equally of arbuscules and hyphal coils. Between seasons, taproot dry mass was reduced by 18%, whereas lateral root length increased by 15%. These changes were probably caused by root turnover, which left little initial colonization of roots at the start of the second year. Strikingly, second-year plants did not exhibit a colonization lag phase, whereas a lag of 43 days was seen for the first-year plants alongside. Possible reasons for this difference are discussed.Key words: perennial, arbuscules, hyphal coils, taproot, Ontario.

scholarly journals Arbuscular mycorrhizal fungi favor invasive Echinops sphaerocephalus when grown in competition with native Inula conyzae

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Veronika Řezáčová ◽  
Milan Řezáč ◽  
Hana Gryndlerová ◽  
Gail W. T. Wilson ◽  
Tereza Michalová
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Native Plants ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Plant Invasions ◽  
Soil Disturbance ◽  
Mycorrhizal Networks ◽  
The Family ◽  
Globalized World

AbstractIn a globalized world, plant invasions are common challenges for native ecosystems. Although a considerable number of invasive plants form arbuscular mycorrhizae, interactions between arbuscular mycorrhizal (AM) fungi and invasive and native plants are not well understood. In this study, we conducted a greenhouse experiment examining how AM fungi affect interactions of co-occurring plant species in the family Asteracea, invasive Echinops sphaerocephalus and native forb of central Europe Inula conyzae. The effects of initial soil disturbance, including the effect of intact or disturbed arbuscular mycorrhizal networks (CMNs), were examined. AM fungi supported the success of invasive E. sphaerocephalus in competition with native I. conyzae, regardless of the initial disturbance of CMNs. The presence of invasive E. sphaerocephalus decreased mycorrhizal colonization in I. conyzae, with a concomitant loss in mycorrhizal benefits. Our results confirm AM fungi represent one important mechanism of plant invasion for E. sphaerocephalus in semi-natural European grasslands.

Development of vesicular–arbuscular mycorrhizae in a young sweetgum plantation

1985 ◽  
Vol 15 (6) ◽  
pp. 1061-1064 ◽  
Author(s):  
Paul P. Kormanik
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Fungal Spores ◽  
Arbuscular Mycorrhizal ◽  
Available Phosphorus ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Mycorrhizal Development ◽  
Crown Closure ◽  
Arbuscular Mycorrhizal Fungal

Sweetgum seedlings with vesicular–arbuscular mycorrhizae formed by Glomusetunicatum or Glomusdeserticola in nursery soil with 30 ppm available phosphorus (P) and nonmycorrhizal seedlings grown in nursery soil with 800 ppm available P were outplanted and whole trees were excavated periodically over the next 5 years in the plantation to follow mycorrhizal development. Four months after outplanting, roots of all initially nonmycorrhizal seedlings had formed vesicular–arbuscular mycorrhizae and the degree of root colonization was comparable to that of initially vesicular–arbuscular mycorrhizal seedlings. New feeder roots did not develop on seedlings of any treatment until almost 5 months after planting. By the end of the first growing season and for the remainder of the study, vesicular–arbuscular mycorrhizae development was approximately the same on all seedlings. The proportion of feeder roots colonized by vesicular–arbuscular mycorrhizal fungi stabilized at 65 to 70%; approximately 56% of the cortical tissues of all feeder roots were colonized with arbuscles, vesicles, and hyphae. Periodic assays of the soil in the plantation showed that vesicular–arbuscular mycorrhizal fungal spores gradually declined from an initial high of 3600 spores to 620 spores per 100-cm3 soil sample after 5 years. This decline was probably caused by crown closure of the sweetgum trees which gradually suppressed understory vegetation.

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