Distribution and Habitat of Rhyacotriton variegatus in Managed, Young Growth Forests in North Coastal California

1996 ◽  
Vol 30 (2) ◽  
pp. 184 ◽  
Author(s):  
Lowell V. Diller ◽  
Richard L. Wallace
Keyword(s):  
Rhyacotriton Variegatus ◽  
Young Growth

Erfolg der Jungwaldpflege im Schweizer Mittelland? Analyse und Folgerungen (Essay)

2013 ◽  
Vol 164 (9) ◽  
pp. 262-270 ◽  
Author(s):  
Peter Ammann
Keyword(s):  
Stand Development ◽  
Negative Effects ◽  
Tree Species Composition ◽  
Natural Processes ◽  
Course Of Action ◽  
Tree Thinning ◽  
Swiss Plateau ◽  
Self Differentiation ◽  
The Cost ◽  
Young Growth

Is young growth tending successful in the Swiss Plateau region? Analysis and implications (essay) The effect of the cost-intensive young growth tending used up to the present in the region of the Swiss Plateau is analysed using different approaches. It is evident that young growth tending is not only ineffective with respect to diameter growth but even hinders stand development. Negative effects on quality from young growth tending are also recognised. This is often due to premature interventions in the natural processes of self-differentiation and subsequent systematic errors in the thinning. Furthermore, the effect of tending measures on the tree species composition is often overestimated because in the first 10 to 20 years of stand development, it is primarily the rejuvenation strategy and the site which are decisive. As an alternative course of action, tending concepts are proposed which rely on biological rationalisation and future tree thinning, to achieve future trees which are as vigorous as possible. These are not only more effective, but are also significantly less expensive.

Productivity and Environmental Role of Forest Shelterbelts of Robinia pseudoacacia L. of the Kuban Lowland

2020 ◽  
pp. 88-97
Author(s):  
V.V. Tanyukevich ◽  
◽  
S.V. Tyurin ◽  
D.V. Khmeleva ◽  
A.A. Kvasha ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Land Reclamation ◽  
Poa Pratensis ◽  
Robinia Pseudoacacia ◽  
Average Height ◽  
Middle Aged ◽  
Aboveground Phytomass ◽  
Robinia Pseudoacacia L ◽  
Young Growth

Works on protective afforestation are carried out in order to protect agricultural land from degradation processes, as well as to improve the microclimate of land. The research purpose is to study the bioproductivity and environmental role of Robinia pseudoacacia L. forest shelterbelts in the conditions of the Kuban lowland. The approved and generally accepted methods of forest valuation, forest land reclamation, botany, and mathematical statistics were applied. Plantings were created according to the standard technology for the steppe zone of the Russian Federation. The area of forest shelterbelts is 62.4 ths ha, including 5 % of the young growth (I state class), 80 % of middle-aged forest plantings (II state class), 10 % of maturing plantings (II state class), 5 % of mature and overmature plantings (III state class). Living ground cover is formed by the following species: Koeleria pyramidata L., Poa pratensis L., Festuca pratensis H., Elytrígia repens L., Dactylis glomerata L., and Phlum pratense L. Aboveground phytomass is 100–300 g/m2; height is 25–32 cm. Plantings are characterized by the quality classes: young growth – I and II; middle-aged and maturing – III; mature and overmature – IV. At the age of natural maturity (70 years), the Robinia trunk reaches the average height of 15.1 m with the average diameter of 22.1 cm. The total stock of wood reaches 18, (ths m3), including (ths m3): young growth – 68 (ths m3); middleaged plantings – 14,871 (ths m3); maturing plantings – 2,187 (ths m3); mature and overmature plantings – 1,314 (ths m3). Aboveground phytomass in young growth is 20.2 t/ha; in mature and overmature plantings it is 391.2 t/ha. In the region it is estimated at 17,070 ths t, including (ths t): young growth – 64; middle-aged plantings – 13,753; maturing plantings – 2,032; mature and overmature plantings – 1,221. The share of stem mass reaches 84.5–80.8 %; woody greenery – 4.2–1.5 %; branches – 11.3–17.7 %. Recalculation coefficients of the stock into aboveground phytomass are the following for: young growth – 0.936; mature and overmature forest shelterbelts – 0.929. Phytosaturation of forest shelterbelts varies within 0.314–2.474 kg/m3. Forest shelterbelts have accumulated 8,534 ths t of carbon, which is estimated at 145.1 mln dollars. The sphere of application of the research results is the Krasnodar Krai forestry, which is recommended to create an additional 60 ths ha of forest shelterbelts, which will provide a normative protective forest cover of arable land of 5 % and annual carbon sequestration up to 3.4 t/ha.

Modeling specific gravity and diameter inside bark of western hemlock and Sitka spruce growing in southeast Alaska

2021 ◽  
Author(s):  
Joseph Dahlen ◽  
David Auty ◽  
Eini C. Lowell
Keyword(s):  
Specific Gravity ◽  
Fixed Effects ◽  
Sitka Spruce ◽  
Western Hemlock ◽  
Fit Indices ◽  
Southeast Alaska ◽  
Important Species ◽  
Explanatory Variables ◽  
Cambial Age ◽  
Young Growth

Western hemlock and Sitka spruce are two commercially important species in Alaska with harvests beginning to focus on naturally regenerated young-growth. We developed within-tree models of ring specific gravity (SG) and diameter inside bark (DIB) for young-growth western hemlock and Sitka spruce. Eight even-aged stands (age < 75 years) in southeast Alaska were felled and disks collected from multiple height levels; 128 trees and 451 disks were collected for western hemlock, and 217 trees and 952 disks were collected for Sitka spruce. Radial strips were prepared and scanned using X-ray densitometry. We fitted non-linear mixed-effects models to the data, with cambial age, height within tree, and dominance class used as explanatory variables. The R2 values (fixed effects only) for the SG models were 0.48 and 0.42 for western hemlock and Sitka spruce, respectively. The corresponding fit indices for the DIB models were 0.86 and 0.85 percent for western hemlock and Sitka spruce, respectively. Tree maps depicting the within tree variation in SG showed more variability in Sitka spruce than in western hemlock. The wood and growth properties of young-growth trees in Alaska will continue to become more important as the U.S. Forest Service transitions away from harvesting old-growth trees.

Venturia pirina. [Descriptions of Fungi and Bacteria].

1974 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
Leaf Litter ◽  
Geographical Distribution ◽  
Primary Infection ◽  
Secondary Infection ◽  
Apple Scab ◽  
Black Spot ◽  
Eriobotrya Japonica ◽  
Venturia Pirina ◽  
Young Growth

Abstract A description is provided for Venturia pirina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Principally on pear (Pyrus communis) and other Pyrus spp., also recorded from Eriobotrya japonica (loquat) (Herb. IMI). DISEASE: Causes scab or black spot of pear, which results in loss of quantity and quality of fruit. The disease attacks shoots, buds, leaves and fruit, symptoms and aetiology being very similar to those of apple scab caused by V. inaequalis on Malus spp. (CMI Descript. 401). Dark, more or less circular scabs are produced on leaves and fruit, often with some growth distortion. Infection of young wood is more common than with apple scab and causes pale brown blister-like lesions which burst to release conidia in the following year. GEOGRAPHICAL DISTRIBUTION: Worldwide in temperate and subtropical regions wherever pears are grown (see CMI Map 367, ed. 2, 1968). TRANSMISSION: Epidemiology is similar to that of apple scab. The overwintering saprophytic perithecial stage on leaf litter releases airborne ascospores in spring which infect young growth, and secondary infection by conidia dispersed during wet summer weather also occurs. Overwintering lesions on young wood are more frequent than with apple scab and conidia produced by these in the spring can be an important source of primary infection (46, 2061; 47, 849).

scholarly journals Dispersion to the Tropics of the Spiraea Aphid, Aphis spiraecola Patch

1969 ◽  
Vol 39 (1) ◽  
pp. 32-40
Author(s):  
George N. Wolcott
Keyword(s):  
United States ◽  
Puerto Rico ◽  
Central America ◽  
Pacific Coast ◽  
Virus Disease ◽  
Aphis Spiraecola ◽  
The Pacific ◽  
Northern United States ◽  
The Tropics ◽  
Young Growth

The spiraea aphid, Aphis spiraecola Patch, which previous to 1924 was known only on species of Spiraea in the northern United States, in that year appeared in mass infestations on citrus trees in Florida and Cuba, causing enormous damage by distorting and resetting the young growth. By 1926 it had spread to Puerto Rico, attacking not only various endemic trees and plants, but being implicated in the transmission of a new virus disease of papaya. By 1928, it was reported on citrus from Honduras in Central America, and it has since dispersed to Costa Rica, and on a great variety of hosts to California, Oregon, and Washington on the Pacific Coast.

MICROBES AND NITRATES IN SOILS FROM VIRGIN AND YOUNG-GROWTH FORESTS

1961 ◽  
Vol 7 (5) ◽  
pp. 785-792 ◽  
Author(s):  
W. B. Bollen ◽  
Ernest Wright
Keyword(s):  
Forest Soils ◽  
Ponderosa Pine ◽  
Nitrate Nitrogen ◽  
Nitrate Content ◽  
Soil Incubation ◽  
Red Alder ◽  
Coastal Soils ◽  
Water Holding ◽  
Penicillium Spp ◽  
Young Growth

Penicillium spp. predominated in samples of forest soils except occasionally at depths of more than three inches, when Mucor and Aspergillus spp. sometimes were more abundant. Incubation for 30 days at 28 °C and 50 per cent water-holding capacity frequently increased the percentage of Mucor spp. as well as Penicillium spp. Mucor spp. were consistently more prominent in soils associated with alder than for other coastal soils. Mucor and Aspergillus spp. also appeared often in soil from stands of ponderosa pine growing east of the Cascades.The greatest concentration of nitrogen as NO3− in unincubated soils was found in a young red alder stand. Samples of soil from stands of virgin coastal redwood showed no nitrate nitrogen. Soils from stands of virgin Sitka spruce, however, showed considerable nitrate content, which increased markedly with incubation.With few exceptions, bacteria and actinomycetes were most numerous in F layers of soil. Incubation greatly increased these populations in most soils.

Biomass Regressions for Understory Species in Young-Growth Sitka Spruce–Western Hemlock Forests of Southeast Alaska

2021 ◽  
Vol 95 (1) ◽  
Author(s):  
Annelise Z. Rue-Johns ◽  
Justin S. Crotteau ◽  
David V. D'Amore ◽  
Jeffrey C. Barnard
Keyword(s):  
Sitka Spruce ◽  
Western Hemlock ◽  
Southeast Alaska ◽  
Understory Species ◽  
Young Growth

Open to competition? Competitive density and the growth of young New Zealand ventures

2019 ◽  
Vol 45 (2) ◽  
pp. 343-358
Author(s):  
D Hugh Whittaker ◽  
Benjamin Fath ◽  
Antje Fiedler
Keyword(s):  
New Zealand ◽  
Empirical Evidence ◽  
Jel Classification ◽  
Competitive Dynamics ◽  
Survey Responses ◽  
The Relationship ◽  
Young Growth

Drawing on 180 survey responses from young, New Zealand-based ventures, we investigate effects of the number of perceived serious competitors on venture growth. We find empirical evidence for an inverse U-shaped relationship between competitive density and young venture growth. We further find that persistent innovation – requiring both initial innovative intent and a recent record of innovation – not only promotes young growth but also moderates the relationship between competitive density and young venture growth. Overall, the study shows that the growth of young ventures committed to persistent innovation is less affected by competitive dynamics compared to non-innovators. JEL Classification: L10, L22, L26, O30

Sign in / Sign up

Export Citation Format

Share Document