Do Shade and Shrubs Enhance Natural Regeneration of Douglas-Fir in South-Central Idaho?

1995 ◽  
Vol 10 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Michael Hunt Jones
Keyword(s):  
Natural Regeneration ◽  
Positive Association ◽  
Soil Surface ◽  
Douglas Fir ◽  
National Forest ◽  
Shrub Species ◽  
Preparation Methods ◽  
South Central ◽  
Early Seedling ◽  
Median Date

Abstract Shade duration and shrub composition in microsites with naturally regenerated Douglas-fir seedlings (Pseudotsuga menziesii var. glauca) were compared to randomly located control plots without seedlings in hot, dry group selection cuts in the southernmost Boise National Forest. Shade duration was estimated using a sighting device which allowed quantification of the degrees of the sun's arc intercepted by timber, shrubs, or other obstructions. Measurements were standardized for the median date for summer high temperatures. Seedlings received more whole-day (P<0.001) and afternoon (P<0.001) shade than control plots, and seedlings on southern exposures received more shade than those on other aspects. Seedling plots had more shrub cover than control plots (P<0.007). However, of nine shrub species examined, only buckbrush exhibited a significantly positive association with seedlings. Soil surface temperatures under buckbrush were reduced more than under other species, and unshaded surfaces remained above 50°C for extended time periods. These results suggest that natural regeneration of Douglas-fir may be enhanced by harvest practices and site preparation methods which provide shade during critical stages of germination and early seedling establishment. West. J. Appl. For. 10(1):24-28.

scholarly journals Natural regeneration of flora in cultivated sandalwood

2021 ◽  
Vol 17 (2) ◽  
pp. 544-547
Author(s):  
D. Srikantaprasad ◽  
A.P. Mallikarjuna Gowda ◽  
T.N. Pushpa ◽  
K. Umesha
Keyword(s):  
Plant Diversity ◽  
Tree Species ◽  
Natural Regeneration ◽  
Field Survey ◽  
Grid Method ◽  
Positive Association ◽  
Sample Survey ◽  
Shrub Species ◽  
Cultivation Practice ◽  
Agro Forestry

Sandalwood is now became a component of agro forestry in Karnataka. A field survey was conducted in sandalwood plantation to know the influence of sandalwood and associated cultivation practice on enrichment of plant diversity. Till planting of sandalwood, farmer has followed clean cultivation later allowing the weeds to grow. Sample survey was conducted through grid method. The major biodiversity was contributed by naturally regereated plant species. Seventeen tree species, ten shrub species, five climbers and forty six herbs, mainly belonging to fabaceae, amaranthaceae and poacea were found in the studied plantation indicating positive association of local flora with sandalwood.

scholarly journals Willows Used for Phytoremediation Increased Organic Contaminant Concentrations in Soil Surface

2021 ◽  
Vol 11 (7) ◽  
pp. 2979
Author(s):  
Maxime Fortin Faubert ◽  
Dominic Desjardins ◽  
Mohamed Hijri ◽  
Michel Labrecque
Keyword(s):  
Soil Surface ◽  
Field Work ◽  
Field Studies ◽  
Soil Hydrology ◽  
Intensive Culture ◽  
Shrub Species ◽  
Short Rotation ◽  
Pollutant Concentrations ◽  
Polycyclic Aromatic ◽  
Made In

The Salix genus includes shrub species that are widely used in phytoremediation and various other phytotechnologies due to their advantageous characteristics, such as a high evapotranspiration (ET) rate, in particular when cultivated in short rotation intensive culture (SRIC). Observations made in past field studies suggest that ET and its impact on soil hydrology can also lead to increases in soil pollutant concentrations near shrubs. To investigate this, sections of a mature willow plantation (seven years old) were cut to eliminate transpiration (Cut treatment). Soil concentrations of polychlorinated biphenyls (PCBs), aliphatic compounds C10–C50, polycyclic aromatic hydrocarbons (PAHs) and five trace elements (Cd, Cr, Cu, Ni and Zn) were compared between the Cut and the uncut plots (Salix miyabeana ‘SX61’). Over 24 months, the results clearly show that removal of the willow shrubs limited the contaminants’ increase in the soil surface, as observed for C10–C50 and of 10 PAHs under the Salix treatment. This finding strongly reinforces a hypothesis that SRIC of willows may facilitate the migration of contaminants towards their roots, thus increasing their concentration in the surrounding soil. Such a “pumping effect” in a high-density willow crop is a prominent characteristic specific to field studies that can lead to counterintuitive results. Although apparent increases of contaminant concentrations contradict the purification benefits usually pursued in phytoremediation, the possibility of active phytoextraction and rhizodegradation is not excluded. Moreover, increases of pollutant concentrations under shrubs following migration suggest that decreases would consequently occur at the source points. Some reflections on interpreting field work results are provided.

scholarly journals Effects of substrate availability and competing vegetation on natural regeneration of white spruce on logged boreal mixedwood sites

2018 ◽  
Vol 48 (4) ◽  
pp. 324-332 ◽  
Author(s):  
Nicola A. Kokkonen ◽  
S. Ellen Macdonald ◽  
Ian Curran ◽  
Simon M. Landhäusser ◽  
Victor J. Lieffers
Keyword(s):  
Picea Glauca ◽  
Natural Regeneration ◽  
Negative Impact ◽  
Mineral Soil ◽  
Soil Surface ◽  
White Spruce ◽  
Solid Wood ◽  
Seedling Mortality ◽  
Competing Vegetation ◽  
Survival And Growth

Given a seed source, the quality of available substrates is a key factor in determining the success of white spruce (Picea glauca (Moench) Voss) natural regeneration. We examined the influence of substrate and competing vegetation on survival and growth of natural regeneration of white spruce up to 4 years following harvesting in deciduous-dominated upland boreal mixedwood sites. Feather moss, thick soil surface organic layers, litter, and solid wood were poor substrates for establishment. Early successional mosses establishing on mineral soil, thin organics, and rotten wood were generally favourable microsites but were not highly available on postharvest sites. Mineral soil substrates were not as suitable as expected, likely because on a postlogged site, they are associated with unfavourable environmental characteristics (e.g., low nutrient availability, exposure). There was some evidence that survival and growth of seedlings were improved by surrounding vegetation in the first years, but heavy competing vegetation had a negative impact on older seedlings. Burial by aspen litter greatly increased seedling mortality, especially when combined with a brief period of submergence due to heavy spring snowmelt. The results provide insight into conditions under which natural regeneration could be an option for establishing white spruce following harvesting of deciduous-dominated boreal mixedwood forests.

scholarly journals Soil disturbance and 10-year growth response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades

2002 ◽  
Vol 32 (2) ◽  
pp. 233-246 ◽  
Author(s):  
Ronald Heninger ◽  
William Scott ◽  
Alex Dobkowski ◽  
Richard Miller ◽  
Harry Anderson ◽  
...  
Keyword(s):  
Tree Growth ◽  
Volume Growth ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
Soil Disturbance ◽  
Height Growth ◽  
Douglas Fir ◽  
Negative Effects ◽  
Fine Soil ◽  
Reduced Height

We (i) quantified effects of skidder yarding on soil properties and seedling growth in a portion of western Oregon, (ii) determined if tilling skid trails improved tree growth, and (iii) compared results with those from an earlier investigation in coastal Washington. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were hand planted at eight recent clearcuts in skid ruts in either nontilled or tilled trails, in adjacent soil berms, and in adjacent logged-only portions. Four and 5 years after skidding, rut depths averaged 15 cm below the original soil surface; mean fine-soil bulk density (0–30 cm depth) below ruts of nontilled trails exceeded that on logged-only portions by 14%. Height growth on nontilled trails averaged 24% less than on logged-only portions in year 4 after planting and decreased to 6% less in year 7. For years 8–10, mean height growth was similar for all treatments. Reduced height growth lasted for about 7 years compared with 2 years for coastal Washington. Ten years after planting, trees in skid-trail ruts averaged 10% shorter with 29% less volume than those on logged-only portions. Tillage improved height and volume growth to equal that on logged-only portions. Generalizations about negative effects of skid trails on tree growth have limited geographic scope.

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 &gt;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.

scholarly journals Impact of skidder and high-lead system logging on forest soils and advanced regeneration

2012 ◽  
Vol 49 (No. 6) ◽  
pp. 273-280 ◽  
Author(s):  
M. Modrý ◽  
D. Hubený
Keyword(s):  
Czech Republic ◽  
Forest Ecosystem ◽  
Natural Regeneration ◽  
Soil Surface ◽  
Beech Forest ◽  
Climatic Conditions ◽  
Lead System ◽  
The Impact ◽  
High Lead ◽  
Stand Conditions

The applied skidding technology strongly influences the impact of harvest on the ecosystem and success of natural regeneration. The impact of skidder SLKT 81 and high-lead system Larix 3T on forest soil and natural regeneration was compared under analogical site and stand conditions in a production beech forest in the environs of Brno, Czech Republic. The skidder was found to have greater effects on the soil surface consistency, soil properties and natural regeneration than the high-lead system operations. Although high-lead system operations are more friendly to all parts of forest ecosystem, the skidder may not cause excessive damage when applied under suitable terrain and climatic conditions.

scholarly journals Early Selection of Douglas-Fir across South Central Coastal Oregon, USA

2006 ◽  
Vol 55 (1-6) ◽  
pp. 135-141 ◽  
Author(s):  
C. A. Dean ◽  
R. W. Stonecypher
Keyword(s):  
Genetic Correlations ◽  
Volume Growth ◽  
Douglas Fir ◽  
Early Selection ◽  
Stem Volume ◽  
Direct Selection ◽  
South Central ◽  
Coos Bay ◽  
The Individual ◽  
Age Range

Abstract Details are given of three first-generation progeny tests (CB1, CB2 and CB3) of coastal Douglas-fir (Pseudotsuga menziesii [MIRB.] FRANCO var. menziesii) planted in the Coos Bay region of south-central coastal Oregon in 1973. The three tests included 15 polymix families based on a 10-pollen mix, and 27 families openpollinated on the ortet. The present study gives heritabilities and additive genetic correlations for growth measured between two and 17 years after planting. Correlated responses are estimated for volume at 17 years from early selection for height and diameter. Between four and 17 years after planting the individual heritability (h2) of height of coastal Douglas-fir across the Coos Bay tests was quite stable between h2 = 0.18 and 0.22. The heritability of stem diameter age-forage was consistently much lower than for height. In the critical age range for early selection between five and 10 years the individual heritability of diameter ranged from h2 = 0.07 to 0.10. The additive genetic correlations involving volume-17 and height or diameter increased to high values of rA = 0.80 to 0.84 between eight to 10 years after planting. Before seven years the absolute values of juvenilemature correlations were much lower. The higher heritability of height made this trait the best criterion for early indirect selection to improve mature stem volume growth. Across these Coos Bay tests, early selection on stem height measured at 5-8 years after planting was estimated to produce almost 40% more gain per year in volume-17 compared with direct selection at 17 years on volume-17 itself. The recommendation for maximizing gain per year in mature volume of coastal Douglas-fir at Coos Bay is to select on height at 7-8 years when the mean height of trees in tests should be around 4.5 to 5.5 meters.

Black Bears Prefer Urea-Fertilized Trees

1989 ◽  
Vol 4 (1) ◽  
pp. 13-15 ◽  
Author(s):  
E. E. Nelson
Keyword(s):  
Pseudotsuga Menziesii ◽  
Dominant Species ◽  
Tree Mortality ◽  
Ursus Americanus ◽  
Douglas Fir ◽  
Black Bears ◽  
National Forest ◽  
Feeding Damage ◽  
Mount Hood ◽  
The Difference

Abstract Feeding damage by black bears (Ursus americanus) to urea-fertilized 25-yr-old Douglas-firs (Pseudotsuga menziesii) in the Mount Hood National Forest, Oregon, resulted in tree mortality four times as severe as among unfertilized trees. Damage was most apparent following application of urea at 448 kg N/ha in 1972, and 224 kg N/ha in 1977. Only Douglas-fir, the dominant species in the stand, was attacked. Attacked trees were somewhat larger than the stand average, but the difference was not significant. Bears appeared to be attracted to the more vigorous trees, which were on fertilized plots. West. J. Appl. For. 4(1):13-15, January 1989.

Sign in / Sign up

Export Citation Format

Share Document