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1.
《Scandinavian Journal of Forest Research》2012,27(2):237-246
Rate of growth and wood properties of Sitka spruce (Picea sitchensis (Bong.) Carr.) were investigated in triplet mixtures with lodgepole pine (Pinus contorta Loud.) (Alaskan provenance) and Japanese larch (Larix kaempferi (Lamb.) Carr.), established on nitrogen-deficient, iron pan soils. These ?nursing? mixtures were compared with pure stands of Sitka spruce that had been either regularly or periodically fertilized with nitrogen. Japanese larch promoted a growth rate in Sitka spruce greater than that achieved in the lodgepole pine-nursed spruce and equivalent to the two pure spruce treatments over the duration of the experiment (current age 28 yrs). Growth of regularly fertilized pure Sitka spruce was not significantly greater than that of periodically fertilized pure spruce. Alaskan lodgepole pine controlled branch size on the lower part of the spruce stems more effectively than the other treatments, although this may have been a function of tree size. Branch characteristics of Japanese larch-nursed spruce, however, were similar to those of the pure spruce treatments. Japanese larch caused an imbalance in crown development in the spruce, although it is unclear from the present study whether this will have an influence on stem and wood quality by the end of the rotation. Overall, the evidence from this study suggests that Japanese larch is an effective nurse of Sitka spruce on nitrogen-deficient iron pans, maintaining a rate of growth similar to that of pure Sitka spruce periodically fertilized with nitrogen and higher than that observed in spruce nursed by Alaskan lodgepole pine. 相似文献
2.
The effects of two fungicides (benomyl and captan ‐ at recommended doses and up to three soil drenches) on root development and mycorrhizal colonization of Sitka‐spruce (Picea sitchensis) and ash (Fraxinus excelsior) were examined after 20 weeks growth, under environmentally controlled conditions, in soil from an Irish tree nursery. Although four mycorrhizal types have been found on Sitka‐spruce at the nursery, only one ectomycorrhizal type (Piceirhiza horti‐inflata) was identified on the short roots in this study. An inoculant (Vaminoc: MicroBio Ltd, Hemel Hempstead, UK) was used to inoculate ash and 20‐week‐old seedlings had a higher arbuscular mycorrhizal (AM) colonization in comparison with uninoculated controls. Multiple applications (2–3) of benomyl reduced the length of root and shoot and shoot dry mass of Sitka‐spruce, whereas in ash, it only depressed root length. Benomyl decreased the numbers of ectomycorrhizas of Sitka‐spruce and arbuscular mycorrhizal colonization of Vaminoc‐inoculated ash. A single application of captan stimulated root length and ectomycorrhizal colonization of Sitka‐spruce and root dry mass in ash compared with uninoculated controls. Applications of captan reduced arbuscular mycorrhizal colonization of Vaminoc‐inoculated ash to levels near to those of uninoculated controls. Of the two fungicides used, benomyl had the most deleterious effect on root length and mycorrhizal colonization of Sitka‐spruce and ash. 相似文献
3.
Soil Solution Chemistry and Throughfall Under Adjacent Stands of Japanese Larch and Sitka Spruce at Three Contrasting Locations in Britain 总被引：1，自引：0，他引：1
ADAMSON J. K.; HORNUNG M.; KENNEDY V. H.; NORRIS D. A.; PATERSON I. S.; STEVENS P. A. 《Forestry》1993,66(1):51-68
Soil solution and throughfall chemistry were investigated inadjacent stands of Japanese larch and Sitka spruce at threesites in Britain. Throughfall was collected in open funnel collectorsand soil solution was collected using tensionless tray lysimetersat the base of the H horizon and ceramic cup suction samplersat the base of the B horizon. Sampling took place fortnightlyfor 14 months and samples were analysed for the major ions anddissolved organic carbon. Most ions were present in higher concentrationsunder spruce than larch. Most notably under the spruce at allsites SO4 in throughfall and NO3 Ca and Al in the B horizonwere present in greater concentrations. However there were notrends in fortnightly concentrations of any ion, associatedwith the presence and absence of needles on the larch. Whensolutes are expressed as fluxes the only consistent effect ofspecies on the B horizon is higher quantities of NO3 and NH4under spruce. The study suggests that in areas exposed to atmosphericpollution, thinned stands of larch could have a beneficial rolerelative to Sitka spruce, in the maintenance of low acidityand aluminium concentrations in drainage water. 相似文献
4.
Growing concern about increasing concentrations of greenhouse gases in the atmosphere, and resulting global climate change, has spurred a growing demand for renewable energy. In this study, we hypothesized that a nurse tree crop may provide additional early yields of biomass for fuel, while in the longterm leading to deciduous stands that are believed to better meet the demands for other ecosystem services. Ten different species combinations were planted, with two different stocking densities, at three different sites in Denmark. Significant differences, with regard to biomass production, were observed among the different sites (P?P??1?yr?1 more biomass. The additional biomass production was similar to what was obtained in stands with conifers only (Sitka spruce, Douglas-fir and Japanese larch), which produced 4.9–6.1?t ha?1yr?1 more biomass than the pure beech stands. No effects of initial planting density (P?=?.19), or of initial weeding (P?=?.81), on biomass production were observed. Biomass production of the broadleaved crop was in most cases reduced due to competition. However, provided timely thinning of nurse trees, the qualitative development of the trees will allow for long-term timber production. 相似文献
5.
Summary This study compared the susceptibility of five UK‐grown conifer species to colonization by sapstain fungi in two trials carried out in consecutive years. The conifers consisted of Sitka spruce (Picea sitchensis), Japanese larch (Larix kaempferi), Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and lodgepole pine (Pinus contorta). Freshly cut 1‐m logs were exposed to the available inoculum of sapstain fungi from April to August in a woodland environment in the south east of England. Logs of each species were removed after 1‐, 2‐ and 4‐month exposure and sampled destructively to assess the amount of sapstain. In the second trial, per cent moisture content and concentrations of nitrogen, carbohydrate and phenolic compounds in the sapwood were also measured at the start and end of the trial. After 2 months, only the sapwood of both pine species had significant levels of sapstain; mean values of 37% and 19% for lodgepole pine (year 1 and year 2 respectively) and 12% and 1% for Scots pine. After 4 months, the levels of sapstain in both pine species exceeded 60% in both years. By contrast, very little sapstain developed in the other conifer species with maximum mean values of 10% for Norway spruce, 3.5% for larch and less than 1% for Sitka spruce. Overall, the moisture content of the logs decreased progressively in all species over the length of the trial. However, pine logs tended to retain higher levels of moisture throughout the trial compared with spruce or larch. The relatively higher moisture content of pine sapwood may be closer to the optimal moisture content that sapstain fungi require for infection and colonization, thereby contributing to the increased susceptibility of pine compared with the other conifer species. The pine logs also suffered from some colonization by bark beetles (Ips sexdentatus), which increased the inoculum potential and the opportunity for colonization by sapstain fungi. In addition, particular phenolic compounds in conifer sapwood may play a role in determining the resistance of some species to sapstain. Notably the most resistant species, Sitka spruce, was the only softwood that still retained detectable levels of phenolics in the sapwood to the end of the trial. 相似文献
6.
Tuula Piri 《Forest Pathology》1996,26(4):193-204
The occurrence of Heterobasidion annosum in stumps and growing trees was investigated on 15 forest sites in southern Finland where the previous tree stand had been Norway spruce (Picea abies) infected by H. annosum, and the present stand was either Scots pine (Pinus sylvestris), lodgepole pine (Pinus contorta), Siberian larch (Larix siberica), silver birch (Betula pendula) or Norway spruce 8–53 years old. Out of 712 spruce stumps investigated of the previous tree stand, 26.3% were infected by the S group and 0.3% by the P group of H. annosum. The fungus was alive and the fruit bodies were active even in stumps cut 46 years ago. In the subsequent stand, the proportion of trees with root rot increased in spruce stands and decreased in stands of other tree species. On average, one S type genet spreading from an old spruce stump had infected 3.0 trees in the following spruce stand, 0.5 trees in lodgepole pine, 0.3 trees in Siberian larch, 0.05 trees in Scots pine and 0.03 trees in silver birch stand. Although silver birch generally was highly resistant to the S type of H. annosum, infected trees were found on one site that was planted with birch of a very northern provenance. 相似文献
7.
《Forest Ecology and Management》1997,96(3):189-196
A typically mediterranean forest of Pinus halepensis wass tudied. During two years following fruiting fungal species, the number of sclerotia in soil, and the percentages and types of mycorrhizas present were determined. In burned stands ascomycetes were typical carbonicolous while basidiomycetes were strongly reduced. The sclerotia extracted from soils were mainly Cenococcum. The number of sclerotia in burned stands was greater than in unburned stands. Seven types of mycorrhizas were recognized in Pinus halepensis root systems from bioassays: Cenococcum, E-strain, Rhizopogon, Suillus, Tuber, Xerocomus, and one non-identified. Nearly 100% of the roots were colonized by mycorrhizal fungi. Ectendomycorrhizas represented 50–90% of the total number. The predominant type is ectendomycorrhizas formed by ascomycetes included in the E-strain group. 相似文献
8.
The growth of semi-checked Sitka spruce (Picea sitcbensis Carr.)on heathland has been stimulated to different degrees by theannual application of litter of Scots pine (Pinus sylvestrisL.), Corsican pine (P. nigra var. calabrica Schneid), Lodgepolepine (P. contorta Dougl.), Japanese larch (Larix leptolepisGord.), and Sitka spruce, at rates corresponding to normal plantationconditions, following an initial heavier rate. Foliar analysissuggests that the response is at least partially attributableto the influence of the litters on the nitrogen nutrition ofthe spruce and differences between litters appear to be largelydetermined by their total nitrogen contents. In this respect,Japanese larch, with an annual needle fall generally greaterthan that of the pines and a higher nitrogen content, offersthe best promise as a nurse species for spruce. 相似文献
9.
The ancestral habitat of capercaillie in most of its range isScots pine forest with an understorey of blaeberry. Keillourforest in Perthshire is dominated by Sitka spruce, has littleblaeberry, yet had a high density of capercaillie. Food andhabitat use by capercaillie were studied there from 1991 to1994. Seven cocks and two hens were caught, and marked withsmall radio transmitters. The habitats they occupied and foodremains in their droppings provided information on home range,habitat utilization and diet through the year. Sitka sprucewas the main food in autumn, winter and spring but was equalledby the fruiting heads of sedge in summer. Larch was the secondmost abundant item in spring and autumn diets. Sedge was plentifulon the wet restocks associated with the gleyed soils at Keillourand may provide a partial substitute for blaeberry in summer.Capercaillie showed a clear preference for the oldest blocksof trees, especially in winter. Sitka spruce, Norway spruceand Scots pine were used roughly in proportion to their availabilityin the birds' home range, but larch stands were used more thanexpected from availability. In summer, all birds used restocksto some extent. Management recommendations to encourage capercailliein commercial plantations largely comprising exotics are thatmature stands over 45 years and well-vegetated restocks shouldeach occupy at least 20 per cent of the forest, larch and blocksof mixed conifers each at least 15 per cent of the ground. Blaeberryshould be encouraged and, if possible, patches of windthrowinvolving living trees with the main root intact should be retained. 相似文献
10.
The incidence of longitudinal drought cracks in coniferous trees may increase as a consequence of climate change. While larger diameter trees are more prone to splitting, it is unclear why only some of the larger trees within the same stand typically suffer damage. Matched pairs of trees of the same size with and without cracks were studied in two adjacent pole-stage mixed stands of Sitka spruce/grand fir (Picea sitchensis/Abies grandis) and Sitka spruce/noble fir (Picea sitchensis/Abies procera) located in North-East Scotland. A range of attributes were measured on 15 damaged and undamaged trees of each species. Length and position of cracks on stems were also recorded, and annual ring width and latewood percentage measured on cores. Noble fir had significantly longer cracks and these were located higher in the stem than the other species. Fewer cracks formed on east-facing side of stems in all species suggesting that prevailing westerly winds may place greater tensile forces on the damaged sides of stems. A higher proportion of latewood (associated with higher tangential shrinkage) was found in the firs and may explain the greater incidence of cracking on grand and noble fir stems (13% and 16%, respectively) in comparison with Sitka spruce (3%). 相似文献
11.
Narcisa Urgiles Paúl Loján Nikolay Aguirre Helmut Blaschke Sven Günter Bernd Stimm Ingrid Kottke 《New Forests》2009,38(3):229-239
Most tree species in tropical mountain rain forests are naturally associated with arbuscular mycorrhizal fungi. Previous studies
in southern Ecuador of 115 tree species revealed that only three species were not associated with arbuscular mycorrhizal fungi.
Seedlings of tropical tree species raised in the nursery may need to be associated with arbuscular mycorrhizal fungi to survive
transplantation shock in higher numbers. Methods for establishing plantations with native tree species are not yet established
for Ecuador. Thus, we investigated the feasibility of using mycorrhizal roots of seedlings of Inga acreana, Tabebuia chrysantha, Cedrela montana and Heliocarpus americanus that had trapped mycorrhizal fungi from forest humus in the nursery to inoculate C. montana and H. americanus with native arbuscular mycorrhizal fungi. Inoculation with either a mixture of mycorrhizal roots from the four species or
only with mycorrhizal roots from the same tree species were compared with effects of moderate fertilization. Assessment of
plant growth and mycorrhizal status of 6-months-old Cedrela montana and Heliocarpus americanus revealed an improvement in growth and diverse associated fungi through mycorrhizal root inoculation in comparison with moderate
fertilization. Moderate fertilization did not suppress mycorrhization. 相似文献
12.
There is a need for selective foliar-acting herbicides for transplantlines in forestry nurseries and new forestry plantings. Toleranceof 2-year-old pot-grown trees of beech, birch, sycamore, ash,cherry, oak, red alder, Japanese larch and Sitka spruce to contactherbicides applied at different dates in the growing seasonwas investigated.Clopyralid was safe to use on all species apartfrom some fresh weight reduction in Japanese larch. Bentazoneand phenmedipham caused initial necrosis on most species tested;however, most trees outgrew the effect of phenmedipham in thefollowing season. Bentazone, generally, had a long-term inhibitoryeffect on growth of alder and at the highest dose tested (5.2kg ha–1 ) also affected ash and beech.Metsulfuron-methyland tribenuron-methyl were safe on most species tested.However,fresh weight reductions were caused by metsulfuron-methyl inash and cherry and by tribenuron-methyl in alder. Mecoprop damagedall species, apart from Sitka spruce. 相似文献
13.
Willis John L. Harrington Constance A. Brodie Leslie C. Roberts Scott D. 《New Forests》2021,52(2):329-348
Promoting patchy recruitment of shade tolerant tree species into the midstory is an important step in developing structural diversity in second-growth stands. Variable-density thinning (VDT) has been proposed as a strategy for accelerating structural diversity, as its combination of within-stand treatments (harvest gaps, thinning, and non-harvested skips) should create variable overstory and understory conditions. Here we report on western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedling and sapling densities in five mixed-conifer stands and Sitka spruce (Picea sitchensis (Bong.) Carr.) seedling and sapling densities in two stands in western Washington at 3,7, 10, and 16–17 years after VDT. Additionally, we report on western hemlock advance regeneration growth and survival in two stands over 14 years. Western hemlock seedling density was highest in the thinned treatment but only significantly so in Year 10. In contrast, the gaps contained significantly more western hemlock saplings in Years 7 and 10 and significantly greater growth of western hemlock advance regeneration through Year 10. Skips embedded within the VDT did not differ significantly from unharvested reserves in terms of seedling or sapling densities of either species. Sitka spruce seedling density was highest in the gap and thinned treatments, but saplings were uncommon in all treatments. Collectively, these results indicate that our variant of VDT promoted patchy, midstory recruitment of western hemlock but failed to recruit Sitka spruce saplings in either stand where it established. Consequently, more intensive variants of VDT may be required to promote midstory recruitment of species less tolerant of shade than western hemlock.
相似文献14.
Gerald Dirnberger Angela-Elisabeth Kumer Eduard Schnur Hubert Sterba 《Annals of Forest Science》2017,74(1):8
Key message
Trees with otherwise equal dimensions have different leaf areas if they are located in different stand types. While leaf area of European larch is affected by mixture proportion, leaf area of Norway spruce is affected by stand density.Context
Leaf area is a key parameter for evaluating growth efficiency of trees, and therefore needs to be measured as consistently and accurately as possible. This is even more important when comparing monospecific and mixed stands.Aims
The aim of the study is to find combinations of parameters and allometric relationships that can be used to estimate accurately the leaf area of individual trees.Methods
Allometries of the measured leaf area of 194 trees in 12 stands were analysed in order to find variables affecting leaf area. Existing functions from the literature were validated. Finally, models were fitted to find the most appropriate method for estimating leaf area of mixed and monospecific stands of Norway spruce and European larch.Results
Allometric relationships of leaf area to other measurable characteristics of trees vary in different stand types. Besides individual tree dimensions such as diameter and crown surface area, leaf area of Norway spruce is related to stand density, whereas the leaf area of European larch is dependent on the admixture of Norway spruce in the stand.Conclusion
In contrast to models for estimating individual tree leaf area of Norway spruce, models for leaf area of European larch have to consider mixture proportions in order to correctly interpret the growth efficiency of mixed stands.15.
A Comparison of Element Fluxes in Throughfall beneath Larch and Sitka Spruce at Two Contrasting Sites in the United Kingdom 总被引：1，自引：0，他引：1
Annual chemical fluxes for ten elements beneath larch and Sitkaspruce are presented for contrasting sites in N.E. Scotlandand mid-Wales. The Scottish site is relatively low altitudewith moderate rainfall and the Welsh site is relatively highaltitude with high rainfall; both sites have low air concentrationsof SO2 and NO2 The data show clear differences in throughfallelement fluxes between larch and Sitka spruce of similar ageand, for the same species, between the two sites. For sea-derivedions and Ca, the trees appear to respond differently to thecontrasting climatic and depositional environments at the twosites; this overrides any consistent differences between speciesfor these elements. Species related differences, consistentat both sites, are apparent for H ion, SO4 and the major nutrients.Larch releases more K and P but retains more inorganic N thanSitka spruce. Beneath larch, the H ion flux is approximatelythree times and the SO4 flux 1.5 times that beneath Sitka spruce,indicating that larch is more acidifying than spruce. 相似文献
16.
The tolerance of two broadleaved and two coniferous forestrytree species to overall sprays of three sulfonylurea herbicides,with the potential for bracken control were tested in comparisonwith asulam on outdoor pot experiments, applied at three differentdates. Thifensulfuron-methyl and tribenuron-methyl caused littledamage, however, date of application of these herbicides canaffect the tolerance of some of the tree species. Asulam, usedoutside the recommended time for bracken control, and metsulfuron-methylcaused damage to cherry, oak, Douglas fir and Japanese larch. The tolerance of Sitka spruce to thifensulfuron-methyl and tribenuron-methyl,and a mixture of them applied at six different dates was alsotested. Sitka spruce was not affected at any treatment dateor by mixtures of the two sulfonylurea herbicides. 相似文献
17.
《Forest Ecology and Management》2001,145(3):181-190
Stand susceptibility to defoliation by spruce budworm, Choristoneura fumiferana (Clem.), was examined in the Fort Nelson area of the Prince George Forest Region of British Columbia. In a retrospective study, defoliation maps of the study area were overlaid onto British Columbia Ministry of Forests cover type maps using a geographic information system. Analysis of the combined data identified forest characteristics associated with increased susceptibility to defoliation by spruce budworm. These were stands where the leading species was white spruce (Picea glauca (Moench) Voss), or where spruce was associated with aspen (Populus tremuloides Michx. and P. balsamifera L.) in mixed stands. Susceptibility to defoliation also was related to site quality, level of crown closure and stand age. Spruce stands on medium quality sites (site index 15 to 25 m, at reference breast height age 50 years) were more susceptible than stands on both poor- and high-quality sites. When spruce was mixed with aspen, stands on higher quality sites were more susceptible to budworm attack than poor sites. Open stands, where crown closure was <50%, were more susceptible to attack by spruce budworm than closed canopy stands. Older stands (120–199 years) were more susceptible to budworm attack than younger stands (40–110 years). In defoliated plots monitored for 6 years, tree mortality and top-kill reached a maximum of 30.4 and 47.2%, respectively. The losses varied with level of defoliation and were reduced by applications of the biological pesticide Bacillus thuringiensis. 相似文献
18.
《Scandinavian Journal of Forest Research》2012,27(1):13-19
The morphological and ecological variation of two types of Gremmeniella abietina var. abietina causing scleroderris canker on conifers was investigated in Pinus spp. and Picea sp. sapling stands in northern Finland and the Kola Peninsula. Small - tree type (STT or B type) of G. abietina was detected alone in 13 Scots pine, three lodgepole pine and two Norway spruce sapling stands out of 26 stands investigated, both STT and large - tree type (LTT or A type) were observed in six Scots pine stands, and LTT was detected alone in two Scots pine stands. For the first time, G. abietina was found to injure Norway spruce saplings in a respective plantation in northern Fennoscandia. STT isolates produced statistically significantly more conidia in vitro than LTT isolates. Morphological variation in conidia septation revealed that STT produced conidia with more than five septa more frequently than did LTT. There was a greater range in variation in septation in STT than in LTT, with overlapping between the types. Isolates of both types were equally associated with cankers, coloured wood, pycnidia or apothecia in the infected saplings. 相似文献
19.
Our knowledge of the endophytic fungal community associated with needles of Sitka spruce (Picea sitchensis) is rather limited, which contrasts with the importance of this tree species for forestry in the UK. In our study, we focused on the detailed characterization of multiple isolates tentatively placed into the genera Nothophaeocryptopus and Rhizosphaera that were obtained from needles of Sitka spruce and co-occurring Norway spruce (Picea abies) and Douglas fir (Pseudotsuga menziesii) at four sites in Scotland and Wales. After a thorough analysis of their phenotype and analysis of two nuclear regions (ITS rDNA and gene for β-tubulin), we propose two species new to science and one new combination. Nothophaeocryptopus piceae was isolated from healthy green or brown needles from spruces and is currently known only as a sterile culture, but the taxonomic novelty is well supported by host affinity and results of molecular data analysis. Rhizosphaera minteri may also be distinguished based on the combination of host and molecular data, but morphologically, it is similar to R. pini. Finally, Hormonema merioides and R. pseudotsugae are found to be conspecific and a new combination R. merioides is proposed following the phylogenetic placement of this species. Our study highlights the importance of multiple approaches used in the identification of microfungi associated with coniferous needles. It is evident that morphologically identical fungi may represent distinct species differing in their host range and severity on the host. This study also provides a basis for future monitoring of these fungi associated with important coniferous forestry trees in the UK. 相似文献
20.
J. Rishbeth 《Forest Pathology》1988,18(7):401-408
Information about the entry of Armillaria into first-rotation pine and spruce stands was obtained by searching for infected stumps, rhizomorph systems or trees that had been killed. In pines Armillaria foci were very rare. In pure Norway spruce Armillaria lutea and A. mellea were detected in stumps but rhizomorphs did not extend into the soil; in Norway spruce mixed with oak, by contrast, A. lutea sometimes produced extensive rhizomorph systems. In Sitka spruce small groups of trees had been killed by A. ostoyae. All foci investigated in conifers contained different genotypes of Armillaria and probably originated from spore infection of stumps created by thinning. Some implications of these findings are discussed. 相似文献