scholarly journals A Summary of North American Hardwood Tree Diseases with Bleeding Canker Symptoms

2007 ◽  
Vol 33 (2) ◽  
pp. 122-131
Author(s):  
A.H. Nelson ◽  
G.W. Hudler
Keyword(s):  
North American ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Deciduous Trees ◽  
Tree Diseases ◽  
Hardwood Tree ◽  
Available Information

Although the presence of bleeding cankers on deciduous trees may raise fears of the presence of Phytophthora ramorum, the cause of sudden oak death, other pathogens also cause similar symptoms. This review of hardwood tree diseases with bleeding canker symptoms provides an overview of available information of these diseases, providing a diagnosis guide as well as a stimulus for continued research in these areas.

scholarly journals Spatial and temporal partitioning and tree preference in California woodland ants

2019 ◽  
Author(s):  
Dylan MacArthur-Waltz ◽  
Rebecca Nelson ◽  
Gail Lee ◽  
Deborah M. Gordon
Keyword(s):  
Niche Overlap ◽  
Time Of Day ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Deciduous Trees ◽  
Ant Communities ◽  
Quercus Agrifolia ◽  
Temporal Partitioning ◽  
Ant Community ◽  
Exotic Trees

AbstractSpatial and temporal partitioning of habitat may facilitate diversity and have important impacts on ant communities. To investigate niche overlap in an ant community in a northern California oak woodland, we observed ant foraging on trees in 4 seasonal surveys, each lasting 2 weeks, in a 9.5-hectare plot over the course of a year. Foraging activity in all 5 observed ant species differed by season, time of day, and/or the genera of trees used. Of the 3 ant species most frequently observed, Camponotus semitestaceus was most active during spring and summer nights, Formica moki was most active during spring and summer days, and Prenolepis imparis was most active during both day and night of fall and winter. All ant species preferred native trees to exotic trees and preferred evergreen trees to deciduous trees. Our results suggest that native evergreen oaks such as Quercus agrifolia, currently threatened by sudden oak death (Phytophthora ramorum), may be important for supporting ant biodiversity.

First Report of Phytophthora ramorum Infecting Camellia Flower Buds in North America

2006 ◽  
Vol 7 (1) ◽  
pp. 52
Author(s):  
Steve A. Tjosvold ◽  
David L. Chambers ◽  
Samantha L. Thomas ◽  
Cheryl L. Blomquist
Keyword(s):  
North America ◽  
North American ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Flower Buds ◽  
Flower Bud ◽  
First Report ◽  
The North ◽  
Landscape Plants ◽  
North American Genotype

Camellias are important nursery and landscape plants and are known to be highly susceptible hosts of Phytophthora ramorum, the pathogen that causes Sudden Oak Death. This is the first report of camellia flower bud infection in the field with the North American genotype of P. ramorum Accepted for publication 31 May 2006. Published 25 August 2006.

Forest transformation resulting from an exotic pathogen: regeneration and tanoak mortality in coast redwood stands affected by sudden oak death

2011 ◽  
Vol 41 (4) ◽  
pp. 763-772 ◽  
Author(s):  
Benjamin S. Ramage ◽  
Kevin L. O’Hara ◽  
Alison B. Forrestel
Keyword(s):  
Canopy Cover ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Coast Redwood ◽  
Marin County ◽  
Wildlife Species ◽  
Management Interventions ◽  
Redwood Forests ◽  
Exotic Pathogen ◽  
Notholithocarpus Densiflorus

Sudden oak death is dramatically altering forests throughout coastal California, but little is known about the communities that are assembling in affected areas. This emerging disease, caused by the exotic pathogen Phytophthora ramorum (S. Werres, A.W.A.M. de Cock), has had especially severe effects on tanoak ( Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.H. Oh), a broadleaf evergreen that is abundant in forests dominated by coast redwood ( Sequoia sempervirens (D.Don) Endl.). Tanoak, a valuable food source to numerous wildlife species, is unlikely to successfully regenerate in diseased areas, and thus, affected redwood forests are transitioning to a novel state. In this study, to predict which species might replace tanoak, we investigated regeneration patterns in heavily impacted stands in Marin County, California. Our main findings were as follows: (i) despite reductions in canopy cover, there is no evidence that any species other than tanoak has exhibited a regenerative response to tanoak mortality, (ii) the regeneration stratum was dominated by redwood and tanoak (other tree species were patchy and (or) scarce), and (iii) some severely affected areas lacked sufficient regeneration to fully re-occupy available growing space. Our results indicate that redwood is likely to initially re-occupy the majority of the ground relinquished by tanoak, but also provide evidence that longer-term trajectories are unresolved, and may be highly responsive to management interventions.

scholarly journals Disease on Nursery Stock as Affected by Environmental Factors and Seasonal Inoculum Levels of Phytophthora ramorum in Stream Water Used for Irrigation

Plant Disease ◽  
2008 ◽  
Vol 92 (11) ◽  
pp. 1566-1573 ◽  
Author(s):  
S. A. Tjosvold ◽  
D. L. Chambers ◽  
S. T. Koike ◽  
S. R. Mori
Keyword(s):  
Stream Water ◽  
Disease Incidence ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Nursery Stock ◽  
Stream Sampling ◽  
Flow Through ◽  
High Concentrations ◽  
Electronic Sensors ◽  
Native Host

A pear bait monitoring system was used to detect and quantify Phytophthora ramorum propagules in streams that flow through woodland areas with sudden oak death in Santa Cruz County, CA from 2001 to 2007. Stream propagules were detected most frequently or occurred in highest concentrations in winter and spring. The stream propagule concentration was characterized with statistical models using temperature and rainfall variables from 2004 to 2007. The highest concentrations of propagules occurred when stream sampling was preceded by about 2 months with low maximum daily temperatures and by 4 days with high rainfall. The occurrence of propagules in streams in the summer was mostly associated with infected leaves from the native host Umbellaria californica that prematurely abscised and fell into the water. When the stream water was used for irrigating rhododendron nursery stock from 2004 to 2007, disease occurred only three times in the two wettest springs (2005 and 2006) on plants sprinkler irrigated with stream water with relatively high concentrations of propagules. Disease incidence was described with a statistical model using the concentration of infective propagules as measured by pear baiting and consecutive hours of leaf wetness measured by electronic sensors at rhododendron height. The concentration of infective propagules was significantly reduced after water was pumped from the stream and applied through sprinklers.

Citizen Science Uncovers Phytophthora ramorum as a Threat to Several Rare or Endangered California Manzanita Species

Plant Disease ◽  
2020 ◽  
Vol 104 (12) ◽  
pp. 3173-3182
Author(s):  
Matteo Garbelotto ◽  
Tina Popenuck ◽  
Brett Hall ◽  
Wolfgang Schweigkofler ◽  
Francesco Dovana ◽  
...  
Keyword(s):  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Santa Cruz ◽  
Forest Disease ◽  
Marin County ◽  
Interspecific Differences ◽  
Detached Leaves ◽  
Comparative Susceptibility ◽  
The University ◽  
First Time

The Sudden Oak Death (SOD) Blitzes consist of yearly surveys led by citizen scientists designed to map the distribution of Phytophthora ramorum, cause of the forest disease called SOD, across northern California. During the 2017 Santa Cruz County SOD Blitz, six rare or endangered Arctostaphylos (manzanita) species were found to be possibly symptomatic for the first time. Symptoms included branch cankers and associated canopy mortality, and affected multiple individuals per species. Isolates of P. ramorum were obtained from each of the six species and, through a 30-day-long inoculation experiment on live plants, Koch’s postulates were completed for each one of them, conclusively determining that they all are hosts of this pathogen. Two additional manzanita species were later found to be apparently symptomatic in Marin County. Inoculations on detached branches using an isolate of P. ramorum obtained from one of the six rare species from Santa Cruz County were successful, suggesting that these two species may also be hosts of P. ramorum. Detached leaves of all eight species were also successfully inoculated at the University of California-Berkeley in fall 2018 and then again in spring 2019. In these cases, the same isolate was used for all inoculations, in order to obtain information on the comparative susceptibility of the eight species in question. Both branch and leaf inoculations identified significant interspecific differences in susceptibility. The production of sporangia was low on all species but it was not zero, suggesting that sporulation may cause within-plant and limited across-plant contagion, especially in rainy years.

Novel introductions and epidemic dynamics of the sudden oak death pathogen Phytophthora ramorum in Oregon forests

2020 ◽  
Author(s):  
Nicholas C Carleson ◽  
Hazel Daniels ◽  
Paul Reeser ◽  
Alan Kanaskie ◽  
Sarah Navarro ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Population Dynamics ◽  
Microsatellite Loci ◽  
Forest Ecosystems ◽  
Principal Component ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Clonal Lineage ◽  
Epidemic Dynamics ◽  
One Year

Sudden oak death caused by Phytophthora ramorum has been actively managed in Oregon since the early 2000’s. To date, this epidemic has been driven mostly by the NA1 clonal lineage of P. ramorum, but an outbreak of the EU1 lineage has recently emerged. Here we contrast the population dynamics of the NA1 outbreak first reported in 2001 to the outbreak of the EU1 lineage first detected in 2015. We tested if any of the lineages were introduced more than once. Infested regions of the forest were sampled between 2013-2018 (n = 903) and strains were genotyped at 15 microsatellite loci. Most genotypes observed were transient, with 272 of 358 unique genotypes emerging one year and disappearing the next. Diversity of EU1 was very low and isolates were spatially clustered (< 8 km apart), suggesting a single EU1 introduction. Some forest isolates are genetically similar to isolates collected from a local nursery in 2012, suggesting introduction of EU1 from this nursery or simultaneous introduction to both the nursery and latently into the forest. In contrast, the older NA1 populations were more polymorphic and spread over 30 km2. Principal component analysis supported two to four independent NA1 introductions. The NA1 and EU1 epidemics infest the same area but show disparate demographics owing to initial introductions of the lineages spaced 10 years apart. Comparing these epidemics provides novel insights into patterns of emergence of clonal pathogens in forest ecosystems.

Phytophthora ramorum, the cause of sudden oak death or ramorum leaf blight and dieback

Mycologist ◽  
2004 ◽  
Vol 18 (4) ◽  
pp. 151-156 ◽  
Author(s):  
BÉATRICE HENRICOT ◽  
CHRIS PRIOR
Keyword(s):  
Leaf Blight ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death

Hierarchical habitat selection by North American porcupines in southern boreal forest

2005 ◽  
Vol 83 (10) ◽  
pp. 1333-1342 ◽  
Author(s):  
Patrick Morin ◽  
Dominique Berteaux ◽  
Ilya Klvana
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Populus Tremuloides ◽  
North American ◽  
Deciduous Trees ◽  
Home Ranges ◽  
Trembling Aspen ◽  
Eastern Canada ◽  
Erethizon Dorsatum ◽  
Multi Scale

In habitat-selection studies, a multi-scale approach is considered necessary to ensure that all elements of selection are depicted and that management decisions accurately reflect the needs of the species under study. We examined hierarchy in summer habitat selection in North American porcupines (Erethizon dorsatum (L., 1758)) in Eastern Canada at the scales of landscape, home range, and single tree. We used radiotelemetry to locate and observe animals visually to record their behaviour and exact location in the habitat. Den use in summer was unexpectedly high for some of our animals, which forced us to use a restricted number of locations per individual for comparison among scales. Although porcupines are generalists at the landscape level, selection patterns appear at the home-range and tree levels. Human-used land and conifer forests were least selected features of home ranges, while deciduous forests dominated by trembling aspen (Populus tremuloides Michx.) and mixed forests were most selected. At the tree scale, trembling aspen was found to be selected over other deciduous trees. However, fruit-producing trees were even more selected. This study shows the importance of a multi-scale approach that includes fine-scale selection.

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