Effects of a native forest pathogen, Phellinusweirii, on Douglas-fir forest composition in western Oregon

1993 ◽  
Vol 23 (12) ◽  
pp. 2473-2480 ◽  
Author(s):  
Jenny C. Holah ◽  
Mark V. Wilson ◽  
Everett M. Hansen
Keyword(s):  
Tree Mortality ◽  
Vascular Plant ◽  
Douglas Fir ◽  
Forest Composition ◽  
Native Forest ◽  
Forest Pathogen ◽  
Vascular Plant Diversity ◽  
Center Edge ◽  
Ordination Techniques ◽  
Root Grafts

The fungal pathogen Phellinusweirii (Murrill) Gilbertson (Family: Hymenochaetaceae) causes extensive rot in the roots and bole of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and true firs, eventually leading to tree mortality. The native pathogen spreads slowly via root grafts and root contacts between conifers, leaving behind areas of tree mortality commonly called infection centers. This study determines (i) whether the slow, systematic removal of the Douglas-fir overstory by P. weirii changes the community composition of old-growth and mature forests, (ii) if composition is significantly affected, to what degree P. weirii influences the composition, (iii) what effects the disease has on individual populations, and (iv) whether vascular plant diversity is affected by disease presence. The herb, shrub, and tree strata were randomly sampled within and adjacent to six P. weirii infection centers located in the low-elevation Cascade and Coast ranges of western Oregon. Statistically significant (P ≤ 0.05) differences in species composition between infected and adjacent noninfected forest were found across all sites. Ordination techniques showed that the distance of vegetation to the infection center edge was a major factor underlying the forest community's structure. The average cover of all herbaceous species was higher inside infection centers as compared with outside, for all locations, though statistically significant at only two sites. In general, species differed in their responses to disease presence. Changes in diversity due to the presence of the root rot were statistically significant in three of the six cases (P ≤ 0.05) but the patterns of change differed from site to site. The removal of Douglas-fir overstory has strong effects on the plant community, but the specific patterns depend on the species and site involved.

Native forest pathogens facilitate persistence of Douglas-fir in old-growth forests of northwestern California

2011 ◽  
Vol 41 (6) ◽  
pp. 1256-1266 ◽  
Author(s):  
Ashley E. Hawkins ◽  
Terry W. Henkel
Keyword(s):  
Bark Beetles ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Native Forest ◽  
Gap Formation ◽  
Old Growth ◽  
Forest Pathogens ◽  
Canopy Trees ◽  
White Fir ◽  
Closed Canopy

Forest pathogens and insects can accelerate tree mortality, increase stand structural heterogeneity, and alter tree community composition. In northern California, the canopy trees Abies concolor var. lowiana (Gord. & Glend.) Lemmon (white fir) and Pseudotsuga menziesii var. menziesii (Mirbel) Franco (Douglas-fir) co-occur but vary in shade tolerance and regenerative abilities following disturbance. Field observations suggested that mortality and turnover of white fir exceeded that of Douglas-fir and that native pathogens may be important drivers in the absence of fire. Pathogens and bark beetles were sampled in old-growth white fir – Douglas-fir stands in northwestern California to assess their contribution to tree mortality, gap formation, and regeneration. We determined abundances and size class distributions of canopy trees, presence of pathogens and bark beetles, and causes of tree mortality. We sampled canopy gaps and closed-canopy forests for overstory species composition, cause of mortality of gap-maker trees, and regeneration of white fir and Douglas-fir. Root-rot fungi accounted for significantly higher mortality and gap formation in white fir than in Douglas-fir. Relative seedling–sapling density of Douglas-fir was higher in pathogen-induced canopy gaps than in closed-canopy forest. In the absence of fire, native forest pathogens enable regeneration and persistence of Douglas-fir by enhancing mortality of white fir, resulting in canopy gap formation.

Vegetation and vascular plant diversity of islands surrounding Port Shelter, Hong Kong, China

2011 ◽  
Vol 19 (5) ◽  
pp. 605-609
Author(s):  
Hu Puwei ◽  
Xing Fuwu ◽  
Chen Lin ◽  
Wang Meina ◽  
Wang Faguo ◽  
...  
Keyword(s):  
Hong Kong ◽  
Plant Diversity ◽  
Vascular Plant ◽  
Vascular Plant Diversity

scholarly journals Over half of western United States' most abundant tree species in decline

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hunter Stanke ◽  
Andrew O. Finley ◽  
Grant M. Domke ◽  
Aaron S. Weed ◽  
David W. MacFarlane
Keyword(s):  
United States ◽  
Tree Species ◽  
Tree Mortality ◽  
Temperate Forests ◽  
Size Structure ◽  
Forest Disturbance ◽  
Population Decline ◽  
Western United States ◽  
Scale Transformation ◽  
Forest Composition

AbstractChanging forest disturbance regimes and climate are driving accelerated tree mortality across temperate forests. However, it remains unknown if elevated mortality has induced decline of tree populations and the ecological, economic, and social benefits they provide. Here, we develop a standardized forest demographic index and use it to quantify trends in tree population dynamics over the last two decades in the western United States. The rate and pattern of change we observe across species and tree size-distributions is alarming and often undesirable. We observe significant population decline in a majority of species examined, show decline was particularly severe, albeit size-dependent, among subalpine tree species, and provide evidence of widespread shifts in the size-structure of montane forests. Our findings offer a stark warning of changing forest composition and structure across the western US, and suggest that sustained anthropogenic and natural stress will likely result in broad-scale transformation of temperate forests globally.

The significance of deadwood for total bryophyte, lichen, and vascular plant diversity in an old-growth spruce forest

Plant Ecology ◽  
2014 ◽  
Vol 215 (10) ◽  
pp. 1123-1137 ◽  
Author(s):  
Sebastian Dittrich ◽  
Mascha Jacob ◽  
Claudia Bade ◽  
Christoph Leuschner ◽  
Markus Hauck
Keyword(s):  
Plant Diversity ◽  
Vascular Plant ◽  
Spruce Forest ◽  
Old Growth ◽  
Vascular Plant Diversity

scholarly journals Relationship between moth (night active Lepidoptera) diversity and vegetation characteristics in southern Sweden

2020 ◽  
Vol 24 (6) ◽  
pp. 1005-1015
Author(s):  
Torbjörn Tyler
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Plant Diversity ◽  
Vascular Plant ◽  
Habitat Characteristics ◽  
Vegetation Composition ◽  
Vascular Plant Diversity ◽  
Site Characteristics ◽  
Tree Canopy Cover ◽  
Wide Range

Abstract The diversity and community composition of moths (both macro- and micromoths) at 32 sites, representing a wide range of habitat types (forests, grasslands, wetlands, agricultural and urban areas) within a restricted region in central Scania, southern-most Sweden, was investigated by use of light moth traps and compared with vascular plant species richness and habitat characteristics. The results revealed a highly significant general association between vegetation composition and the composition of the moth community and multivariate (CCA) analyses indicated light availability and soil fertility parameters (pH and macronutrients) to be the habitat characteristics that best correlated with moth community composition. Less strong, but still significant, positive relationships between moth abundance and local vascular plant diversity were also revealed. Moth species richness was positively correlated with diversity of woody plant genera in the neighborhood, but not with local vascular plant diversity in general. As for more general site characteristics, there were tendencies for higher moth richness and abundance at sites with more productive soils (well-drained, high pH, high nutrient availability), while shading/tree canopy cover, management, soil disturbance regimes and nectar production appeared unrelated to moth community parameters. It is concluded that local moth assemblages are strongly influenced by site characteristics and vegetation composition. Implications for insect conservation: The results show that obtaining moth data on a local scale is useful for conservation planning and does not need to be very cumbersome. Local moth assemblages monitored are indeed related to local site characteristics of conservation relevance.

scholarly journals Bryophyte diversity is related to vascular plant diversity and microhabitat under disturbance in karst caves

2021 ◽  
Vol 120 ◽  
pp. 106947
Author(s):  
Hai Ren ◽  
Faguo Wang ◽  
Wen Ye ◽  
Qianmei Zhang ◽  
Taotao Han ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Vascular Plant ◽  
Karst Caves ◽  
Vascular Plant Diversity

scholarly journals Genetic diversity in introduced Douglas-fir and its natural regeneration in Central Europe

2019 ◽  
Vol 93 (4) ◽  
pp. 535-544
Author(s):  
Charalambos Neophytou ◽  
Marcela van Loo ◽  
Hubert Hasenauer
Keyword(s):  
Genetic Diversity ◽  
Central Europe ◽  
Natural Regeneration ◽  
Forest Tree ◽  
Douglas Fir ◽  
Native Forest ◽  
Next Generation ◽  
Planted Forests ◽  
Seed Sources ◽  
The 19Th Century

Abstract Since its first introduction in the 19th century, Douglas-fir has become the economically most important non-native forest tree species in Central European countries. Many of these planted forests are important seed sources and/or exhibit natural regeneration. Thus, it is important to assess (1) the genetic diversity of the mature stands and (2) if the genetic diversity can be passed on to the next generations. In order to address these issues, we genotyped mature Douglas-fir individuals and natural regeneration from >100 native and non-native populations using nuclear microsatellite markers. We compared the genetic diversity of native North American populations with mature Douglas-fir populations in Central Europe. The results show that genetic diversity did not differ significantly between European populations and the assigned native origin. Using a subset of 36 sites from Central Europe, we detected a significant reduction in the genetic diversity of adult versus naturally regenerated juvenile trees, indicating a bottleneck effect in the next generation of European Douglas-fir stands. The main reason may be that the mature European Douglas-fir stands are highly fragmented and thus the stand size is not adequate for transmitting the genetic diversity to the next generation. This should be taken into account for the commercial harvesting of seed stands. Seed orchards may offer a potential alternative in providing high quality and genetically diverse reproductive material.

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