Growth of young Pinus ponderosa and Pinus contorta on compacted soil in central Washington

Growth in height, diameter, and volume was measured on 9- to 18-year-old ponderosa pine (Pinus ponderosa) and 10- to 13-year-old lodgepole pine (Pinus contorta) trees growing on or near compacted skid trails in the Yakima Indian Reservation in south-central Washington. Soil bulk density of the 0- to 30.5-cm deep layer was measured with a single-probe nuclear densimeter on two sides of each sample tree and in adjacent undisturbed soil. On three ponderos pine sites logged 23 years before the study, average bulk density on skid trails was 15% greater than on adjacent undisturbed soil. On a lodgepole pine site logged 14 years before the study, soil on skid trails averaged 28% greater bulk density than undisturbed soil.Total growth of ponderosa pine and the last 5 years of growth were significantly related (P = 0.07) by regression analysis to age of trees, site index, basal area of the adjacent overstory, and the percentage of increase in soil bulk density. At the mean increase in soil bulk density, total height, diameter, and volume growth were reduced 5%, 8%, and 20%, respectively.Total growth of lodgepole pine and the last 5 years of height, diameter, and volume growth were significantly related to tree age and the percentage of soil organic matter. Increase in soil bulk density was not significantly related to growth of this species.     

Integration of Northern spotted owl habitat and fuels treatments in the eastern Cascades,Washington, USA

The restoration of natural fire regimes has emerged as a primary management objective within fire-prone forests in the interior western US. However, this objective becomes contentious when perceived to be in conflict with the conservation of rare wildlife species. For example, the integration of fire ecology in disturbance-prone forests of eastern Washington with the recovery of the Northern spotted owl has been described as a management dilemma. We intersected modeled spotted owl habitat with mapped priority fuels treatment areas in order to determine the magnitude of the potential conflict between fuels management and owl conservation. Our results show that there is considerable overlap within dry forests between high suitability spotted owl habitat and moderate-high priority fuels treatment areas (34% overlap). However, there is also considerable overlap of lower suitability spotted owl habitat with moderate-high priority fuels treatment areas (35% overlap) providing opportunities to accomplish multiple management objectives if one considers a landscape perspective. We propose that a conservation strategy for the Northern spotted owl in the eastern Cascades consider the following: emphasize landscape restoration of dry forests within which spotted owl habitat is embedded; landscapes considered for restoration need to be large enough to accomodate the effects of fire disturbances and still retain sufficient habitat to support spotted owl populations; and include adaptive management allowing for adequate monitoring and feedback for managers to make needed adjustments.     

Gremmeniella-infected Pinus contorta as raw material in the production of kraft pulp

Pinus contorta, logs with occluded cankers caused by the pathogen Gremmeniella abietina, as well as logs from unaffected trees were sampled from a 23-year-old plantation in Sweden and compared in terms of their paper properties. Damaged wood gave kraft pulp with poor paper properties: it required a larger amount of beating energy and resulted in paper with low tear strength, air permeability, tensile stiffness, burst strength, and poor light-scattering properties. However, small amounts of damaged wood mixed in with a large amount of healthy wood can pass almost unnoticed. The use of trees with a larger content of damaged wood will lead to serious processing problems and give a pulp with poor paper properties. Thus, wood damaged by Gremmeniella should be sorted out and classed as low-grade raw material.     

Seedling shoot,needle and bud development in three provenances of Pinus sylvestris and Pinus contorta cultivated in northern Sweden

The patterns of current‐year shoot, needle and terminal bud elongation in seedlings of three Scots pine (Pinus sylvestris L.) and three lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) provenances were compared during the third and fourth growing seasons after planting. Lodgepole pine produced longer shoots and buds than did Scots pine, mainly because lodgepole pine formed more stem units and elongated at a faster rate. Stem unit length and the duration of shoot and bud elongation differed relatively little between species and provenances. Lammas or polycyclic growth occurred in some lodgepole pine provenances, but not in any Scots pine provenance, and was associated with enhanced shoot elongation. Needle elongation commenced earlier, proceeded at a faster rate, and was greater in lodgepole pine than in Scots pine, but ceased about the same time in all species and provenances. The heat sum required to attain 50% of final length was lower for shoots and needles in lodgepole pine than in Scots pine, and for shoots in northern provenances than in southern ones. Mitotic activity in the apical meristem of the terminal bud, which occurred less than one week after the seedlings were free from snow, started and ceased about the same time in each species, but was higher in lodgepole pine than in Scots pine early in the shoot elongation period.     

Nitrogen-15 Uptake by Pinus contorta Seedlings in Relation to Phenological Stage and Season

This study measured the amount of uptake of labeled nitrogen (¹⁵N) of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm) seedlings, at three different phenological stages, in a growth chamber experiment. Thirty days after ¹⁵N application, the amount of ¹⁵N recovered in seedlings as a percentage of the total ¹⁵N fertilizer applied was 4% in early spring, 43% in summer and 33% in autumn. The total ¹⁵N recovered in the plant–pot system ranged from 80 to 96%, and is higher than reported in other studies. Total ¹⁵N recovered from the pot compartment alone ranged from 48 to 95%, suggesting that substantial pools of N remain in the soil. Results suggest that low ¹⁵N uptake in the spring was associated with limited development of new root as a result of low spring soil temperatures. The lack of unsuberized roots in spring could be a key factor decreasing the effectiveness of early spring fertilization in the boreal forest.     

马尾松苗针叶氮、磷代谢酶及积累量的动态变化

【目的】以1年生马尾松苗木为研究对象,从马尾松体内氮、磷代谢酶活性及其积累量的角度研究苗木对施肥的响应机制。【方法】设置不同的磷肥及钾肥随机区组试验,分析不同处理下对马尾松苗木叶绿素、氮磷转化酶(NR、ACP)活性以及针叶内氮、磷素的动态变化。【结果】1)马尾松苗木叶绿素、NR及ACP活性随季节变化表现出一定的动态变化:施磷肥处理叶绿素在7月时最高,施钾肥时滞后,8月最高;NR活性则正好相反,呈现先降低后逐渐增加的趋势;ACP活性呈现明显单峰型,8月时活性最高,而后逐渐降低到最先的水平。2)施磷肥增加马尾松针叶中NR及ACP活性,促进了植物中氮元素的分解及代谢,针叶内NR活性及氮素含量均高于对照(P0),施钾肥则表现为前期NR、ACP活性及氮素含量高于对照(K_0),叶绿素a含量高于对照,叶绿素b含量低于对照,叶绿素wa/wb明显高于对照,后期则相反,针叶内氮、磷素积累量表现一致;3)随着施肥量的增加,叶绿素含量及酶活性的变化规律不明显。【结论】马尾松苗木叶绿素、NR及ACP活性呈季节性变化,施磷肥促进氮、磷代谢酶活性,施钾肥仅在生长前期促进苗木体内氮、磷代谢。     

Interrelationships among light,photosynthesis and nitrogen in the crown of mature Pinus contorta ssp. latifolia

Scaling leaf-level measurements to estimate carbon gain of entire leaf crowns or canopies requires an understanding of the distribution of photosynthetic capacity and corresponding light microenvironments within a crown. We have compared changes in the photosynthetic light response and nitrogen (N) content (per unit leaf area) of Pinus contorta Dougl. ssp. latifolia Engelm. (lodgepole pine) leaves in relation to their age and light microenvironment. The vertical gradient in integrated daily photosynthetic photon flux density (PPFD) from the upper to the lower crown of lodgepole pine was similar in magnitude to the horizontal gradient in daily PPFD along shoots from young to old leaves. The relationship between light-saturated net photosynthesis (A(max)) and daily PPFD was significant for both young and old leaves. However, old leaves had a lower A(max) than young leaves in a similar daily irradiance regime. For leaves of all ages from throughout the crown, A(max) was linearly related to the estimated daily net carbon gain that leaves could achieve in their natural PPFD environment (estimated A(day)) (r(2) = 0.84, P < 0.001, n = 39), indicating that estimated A(day) may be dominated by carbon fixed when leaves are light-saturated and operating at A(max). Comparison of the PPFD required to achieve A(max) and the PPFD available to the leaves showed that all of the measured leaves (n = 39), regardless of their position in the crown or age, were in light environments that could light-saturate photosynthesis for a similar proportion of the day. For all data pooled, foliar N was weakly correlated with daily PPFD. Analyzing each leaf age class separately showed that foliar N was significantly related to daily PPFD, A(max), and estimated A(day) for the youngest leaves but not for middle-aged or old leaves. Therefore, the general theory that foliar N is allocated within a crown according to total daily light availability was supported only for young (1-4 years old) leaves in this study.     

Enzymatic interactions between Gremmeniella abietina var. abietina,European race,and two resistant hosts,Pinus banksiana and P. contorta

Ultrastructural observations showed that the European race of Gremmeniella abietina var. abietina can secrete several cell wall–degrading enzymes that help the invasion of Pinus banksiana and P. contorta shoot tip tissues. Alterations in the content or distribution of cellulose were obvious, indicating that colonization might be achieved primarily through the action of glucanases. Polygalacturonases seemed more abundant in the cortex and the phloem of the stem, suggesting they are among the first enzymes secreted by the pathogen during infection. Production of laccases and peroxidases was also revealed but always close to fungal cells or in areas where host wall degradation was obvious. In places where there was an accumulation of phenolic compounds in the infected zones of the shoot, particularly in or near the transition zone, immunolocalization of both enzymes was limited or absent. Laccases and polygalacturonases were regularly detected over the extracellular sheath of G. abietina, and this indicates that the sheath could play a significant role during host wall degradation. Finally, examination of G. abietina wall constituents, such as chitin and β‐1,3‐glucans, suggests that the composition of the pathogen wall changes during the infection process. This change may be associated with the secretion of fungal enzymes but could also be linked to host reactions altering the integrity of pathogen cell walls.     

Effects of Afforestation with Pinus contorta on Nutrient Content, Acidity and Exchangeable Cations in Peat

Nutrient contents, acidity and exchangeable cations in the upper300 mm of peat beneath lodgepole pine have been compared withthose in peat from contiguous unplanted areas at each of sixsites. Nitrogen, phosphorus and potassium contents, which aresignificantly higher in flushed blanket bog peat than in peatfrom either raised bog or unflushed blanket bog, are not significantlyaltered by the presence of trees. Calcium and magnesium contents,on the other hand, although similar in peat from different bogtypes, are lower in peat beneath the tree crop. ExchangeableCa²⁺ Mg²⁺ and K²⁺ are replaced by Na⁺ and H⁺ in planted peatbut the increase in H⁺ content exceeds the loss of base cations,reflecting a higher number of exchange sites. This increaseaccounts for lower values of both base saturation and pH inplanted peat and is attributed to enhanced decomposition promotedby aerobic conditions beneath the tree crop.     

吉林省半干旱区小干松引种栽培试验及抗旱种源的ISSR分析

在小干松抗旱地理种源选择的基础上,采用抗旱种源在吉林省半干旱区的多个典型立地进行了比较栽培试验研究。结果表明,小干松更适宜于在沙荒地上营造。通过多种造林方法比较,总结出小干松沙地造林实用技术。利用ISSR-PCR方法对抗旱种源进行了基因多态分析,依据扩增结果进行遗传距离分析,构建分子树状图,探讨了小干松抗旱种源间的遗传关系和利用ISSR分析进行种源鉴定的可行性。     

红松、日本落叶松与色赤杨、白桦等阔叶树种混交造林技术的研究

红松、日本落叶松与色赤杨、白桦混交造林，直径生长量比纯林提高3％－15％，树高比纯林提高5％－95％，材积比纯林提高18％－99％。     

Influences of postfire salvage logging on forest birds in the Eastern Cascades,Oregon, USA

In coniferous forests of western North American, fire is an important disturbance that influences the structure and composition of floral and faunal communities. The impacts of postfire management, including salvage logging and replanting, on these forests are not well known. We compared densities and relative abundances of forest birds after fire in unsalvaged stands and stands subjected to one of two intensities of salvage logging (moderate, 30 snags retained per ha and heavy, 5–6 snags retained per ha) in mixed-conifer forests in central Oregon. We used analysis of variance with repeated measures to evaluate three hypotheses concerning the influence of different intensities of salvage on densities or relative abundances of sixteen species of birds, and two hypotheses concerning the influence of time since salvage logging on relative abundances or densities of birds. We also examined the relationship between vegetation and abundances of each bird species. We did not detect significant differences among treatments in densities or relative abundances for eight species and one genus of birds. We detected significant differences for seven species, though the patterns differed among species. Relative abundances or densities of the black-backed woodpecker (Picoides arcticus), hairy woodpecker (P. villosus), brown creeper (Certhia americana), western wood-pewee (Contopus sordidulus) and yellow-rumped warbler (Dendroica coronata) were lower in the heavy and moderate salvage treatment compared to the unsalvaged treatment, while densities of the dark-eyed junco (Junco hyemalis) and fox sparrow (Passerella iliaca) were greater in the moderately and heavily salvaged stands than in the unsalvaged treatment. We detected significant differences between years for four species of birds. Our findings suggest that both cavity-nesting and cup-nesting species respond to salvage logging, and that some species respond uniquely to habitat features influenced by salvage logging. For species that responded negatively to salvage logging, the moderate salvage intensity did not appear to mitigate the negative influence of salvage logging. Areas of unlogged burned forest appear to provide important habitat for some species of birds following forest fires. Our findings parallel those of other recent studies of these species, suggesting robust patterns that transcend particular locations.     

Morphological and Ecological Variation of Gremmeniella abietina var. abietina in Pinus sylvestris,Pinus contorta and Picea abies Sapling Stands in Northern Finland and the Kola Peninsula

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.     

Ecosystem management and nonindustrial private forest landowners in Washington State,USA

Washington’s non-industrial private forest (NIPF) landowners control 1.2 M ha, or nearly 20%, of the forestland in Washington State. Results of a mail survey suggest that educated and informed NIPF landowners are more likely to show interest in ecosystem-based management programs. NIPF respondents in Washington State indicated an appreciation for the temporal vision and landscape perspective crucial to understanding the foundation of ecosystem management. It is concluded that public agencies need to involve private landowners in ecosystem-based projects by using a more ‘place’ based cross-boundary management approach. NIPF landowners must be actively involved in the decision-making so that the process, for them, is one of self-governance. Providing landowners with opportunities for education and assistance may offer the best prospects for achieving ecosystem management objectives across diverse ownerships     

朝阳县油松、刺槐、华北落叶松树高生长模型研究

收集朝阳县主要造林树种油松、刺槐和华北落叶松的解析木数据,按照不同立地类型对数据进行分类整理,运用6种高生长模型对树高生长进行拟合和研究.结果表明,大部分树种高生长用Logistic模型最佳,油松在阴坡厚土层和阳坡厚土层的高生长用Richards方程最佳.相对生长方程在刺槐阳坡中土层和阳坡厚土层的高生长模拟也取得了满意的结果.     

Effects of drought on non-structural carbohydrates and C,N, and P stoichiometric characteristics of Pinus yunnanensis seedlings

To study non-structural carbohydrate characteristics and nutrient utilization strategies of Pinus yunnanensis under continuous drought conditions, 2-year-old seedlings were planted in pots with appropriate water, light and moderate and severe drought treatments [(80 ± 5),(65 ± 5),(50 ± 5), and(35 ± 5)% of field water-holding capacity].Non-structural carbohydrates, carbon(C), nitrogen(N),and phosphorus(P) concentrations were measured in each plant component. The results show that:(1) With increas...     

油松人工林新生枝叶碳氮磷含量及化学计量比对氮添加的响应

为探究氮(N)添加对油松(Pinus tabuliformis)人工林养分利用策略的影响及其随林龄的变化,以4个林龄油松人工林为对象,研究5个梯度(0、5、10、15和20 g/m2)N添加量对新生枝叶碳(C)、氮(N)和磷(P)含量及其化学计量比的影响,揭示油松人工林N利用策略及其对N添加的响应.结果显示,油松人工林新生枝叶的TC、TN和TP含量均随N添加量的增加呈先增加后减少的趋势,均在10或15 g/m2添加量下最高;枝叶的TC、TN和TP含量在不同林龄间均存在差异,枝的变幅分别为7.53％、13.37％和18.67％,叶的变幅分别为7.74％、13.67％和29.61％.新生枝叶的C/N、C/P和N/P均随N添加量的变化小幅变化,平均变幅为3.99％～9.91％;随N添加量增加,枝叶的C/N和C/P均呈先降低后升高的趋势,N/P持续升高;随林龄增加,枝叶的C/N和C/P均呈先升高后降低的趋势,均在37年生时最大,枝的N/P持续升高,叶的N/P先升高后降低.油松人工林生长受N限制严重;随N添加量和林龄增加,N限制有所缓解.     

Influences of climate,fire, grazing,and logging on woody species composition along an elevation gradient in the eastern Cascades,Washington

Across western North America, current ecosystem structure has been determined by historical interactions between climate, fire, livestock grazing, and logging. Climate change could substantially alter species abundance and composition, but the relative weight of the legacy of historical factors and projected future conditions in informing management objectives remains unresolved. We integrated land use histories with broad scale climatic factors to better understand how inland Pacific Northwest ecosystems may develop under projected climates. We measured vegetation structure and age distributions in five vegetation types (shrub steppe to subalpine forest) along an elevation gradient in the eastern Cascades of Washington. We quantitatively assessed compositional changes, and qualitatively summarized the environmental history (climate, fire and fire suppression, grazing, and logging) of each site. Little change was evident in woody species composition at the shrub steppe site. At the shrub steppe/forest ecotone, densities of drought-tolerant Artemisia tripartita and Pinus ponderosa increased. In the dry conifer, montane, and subalpine forest sites, increases in Pseudotsuga menziesii, Abies grandis, and Abies lasiocarpa, respectively, and decreases in Pinus ponderosa, Larix occidentalis, and Pinus contorta, respectively, have shifted species composition from fire and drought-tolerant species to shade-tolerant species. Fire suppression, grazing, and logging explain changes in species composition more clearly than climate variation does, although the relative influence of these factors varies with elevation. Furthermore, some of the observed changes in composition are opposite what we expect would be most suited to projected future climates. Natural resource managers need to recognize that the current state of an ecosystem reflects historical land uses, and that contemporary management actions can have long-term effects on ecosystem structure. Understanding the processes that generated an ecosystem's current structure will lead to more informed management decisions to effectively respond to projected climate changes.