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1.
Dorota Dobrowolska 《Forest Ecology and Management》1998,110(1-3):237-247
Over the last 20 years, investigations have been carried out to determine the influence of various ecological factors on silver fir natural regeneration in highlands and mountains. However, there has been little research on the structure and development of fir regeneration in lowlands. Results of this study indicate that three main stand characteristics play a very important part in the structure of fir regeneration in the lowland. The results revealed that the quantity, frequency and growth rate of fir regeneration were affected by site conditions. One of the most important ecological factors differentiating quantity and quality of fir regeneration was the proportion of fir in a stand. It was found that, with an increase in the percentage of fir in a stand, the quantity and the sum of heights and the sum of height increments of fir regeneration tends to increase. Results of this study showed that the number and development of fir regeneration were influenced by species composition of a stand; fir regenerated not only in pure fir stands but also in mixed forests. A positive influence of pine and birch canopy on initiation and development of fir regeneration was confirmed. Optimal conditions for the growth and development of fir with respect to species composition were found in mixed fir stands with an admixture of hornbeam. In contrast, results of the study suggest that the worst conditions for fir regeneration were found in the stands composed of species, such as ash, alder, oak, aspen, lime and spruce. 相似文献
2.
Vaidotas Lygis Remigijus Bakys Alma Gustiene Daiva Burokiene Antanas Matelis Rimvydas Vasaitis 《European Journal of Forest Research》2014,133(3):501-510
Due to the dieback caused by invasive fungus Hymenoscyphus pseudoalbidus, ash is threatened in many regions of Europe. In order to predict the situation with ash ecosystems, it is important to examine forest regeneration in areas formerly dominated by ash with long disease history and known management. The main aim of the present study was, therefore, to evaluate forest self-regeneration following clear-felling of ash dieback-devastated stands, focusing on ash. In Lithuania, during 2011, a forest regeneration inventory was performed on twenty clear-cuts, initially dominated by stands of ash, but severely damaged by the dieback caused by H. pseudoalbidus and clear-felled 1–10 years previously. In subsequent forest regeneration, grey alder and birch dominated. Ash regeneration was scarce, and its proportion decreased from 40–100 % in pre-dieback stands to 0–21 % in current stands. Of all observed ash trees (n = 775), 53.9 % were diseased, 16.8 % were dead, and only 29.3 % were visually healthy. Moreover, ash was among the slowest growing species, while grey alder, aspen and birch were the fastest. The regeneration and health condition of ash in forests, where previous to the dieback ash was dominant, demonstrated a sharp decrease in occurrence of this species and a clear shift in species composition towards grey alder and birch. 相似文献
3.
《Scandinavian Journal of Forest Research》2012,27(1-4):355-370
Observed diameter distributions of forest stands are adapted to the Johnson S b probability function. The stands investigated are untreated mixed stands of Norway spruce (Picea abies (L.) Karst.) and birch (Betula pendula Roth and Betula pubescens Ehrh.) aged between 20 and 32 years. The adaptation of the Johnson Sb probability function is made both on mixed spruce and birch, and on each species separately. Altogether 156 observations were tested with observed distributions against calculated distributions in the Kolmo‐gorov‐Smirnov test. The fractiles are predicted with multiple regression and two multivari‐ate techniques, simultaneous‐equation models (multivariate regression) and partial least squares with latent variables. The independent variables are characteristics of site and stand. Both multivariate methods predict diameter distribution well when tested. 相似文献
4.
Complexity of uneven-aged forests results from the heterogeneity of their structure reflected among others by the spatial pattern of their components. Forest structure is usually modified by various processes operating at different scales and time. Structure and processes are not independent, and both are important drivers of forest dynamics. The impact of natural processes on forest structure manifested in the specific spatial pattern of trees can be quantified by point pattern analysis applied to long-term repeatedly measured stem-mapped plots. Such studies are relatively scarce in the literature although they provide better insight into the mechanisms affecting forest dynamics. Our study is focused on the spatiotemporal analysis of the structure of mixed uneven-aged Scots pine-dominated forest located at the Kampinoski National Park (Poland). Univariate analysis showed that the initial pattern of all live trees was initially random and it shifted toward more uniform with forest aging. Spatial patterns of individual tree species varied from that stated for all forest community. We observed changes in spatial pattern of Scots pine and common oak from random toward more clumped (pine) or uniform (oak) pattern. In case of black alder and common birch, the initial aggregated pattern was maintained over the examined 14-year period of the forest succession. Bivariate analysis showed that the most common interspecific association between pairs of tree species was spatial segregation (pine vs. alder, alder vs. birch and oak vs. birch) followed by spatial independence (pine vs. oak and oak vs. alder). The positive association was stated only for pine and birch and only for certain spatial scales (> 5 m). Simultaneously, at small distances they showed reciprocal repulsion. Changes in spatial relationships between tree species were negligible over 14-year period of forest succession. Our results confirmed the density-dependent mortality process in the uneven-aged Scots pine-dominated forest over 14-year period of forest development. Our study showed that spatial interactions between individuals along with species-specific ecological requirements should be incorporated into realistic models of forest development, helping to manage the forest ecosystems toward their greater structural complexity. 相似文献
5.
Broad-lcavedKoreanpincforcstisthcclimaticclimaxconinunitVofnortheastmoun-tainousregionsofChina.AsthemaintreesPecies,Koreanpinehasexccllentwood.AgreatattentionbasbccnpaidtorecoveringtheseforesttyPesafterharvesting.Additional1y,KoreanpineisoneofkeyregcncrationtreesPeCiesinthisregion.TherehasbeenlargeareaofKorcanpincplantations.Howevcr,thercaresomeproblemsncedingtobestUdicdfwtheramongwhichoneistoselectsuitabIeropenerationapproacl1esofKoreanpincforesls.WHATISTHEPROBLEM?ThcnatUralregen… 相似文献
6.
Gunnar Morozov Jürgen Aosaar Mats Varik Hardo Becker Krista Lõhmus Allar Padari 《Scandinavian Journal of Forest Research》2019,34(1):12-25
The decomposition of the leaf litter, fine roots (d?<?2?mm) and coarser roots (2?≤?d?<?5?mm) of grey alder and silver birch, as well as of α-cellulose sheets using the litterbag method was studied in two experimental stands on Podzoluvisol soils in Southern Estonia. For both tree species, the coarser roots decomposed faster than the fine roots, (p?<?.05), tree species did not affect the decomposition rate of the roots (p?>?.5). The nitrogen (N) input to soil from aboveground litter was multiple times higher than the N flux from roots. The remaining relative ash-free mass of the leaves of grey alder and silver birch after three and a half years was similar. After 11 years the remaining relative ash-free mass of the fine and coarser roots of grey alder still accounted for around 10% of the initial value. For silver birch the remaining value was around 20% after 9 years. The litterbag method to underestimates in fertile soils the decomposition of organic matter and thus did not reflect the actual dynamics of decomposition. 相似文献
7.
《Scandinavian Journal of Forest Research》2012,27(3):223-234
Absence of, or poor, oak (Quercus spp.) regeneration is a problem in uneven-aged, mixed closed-canopy broadleaved forests. Browsing by ungulates on small trees may contribute to poor oak regeneration in such forests. This possibility was investigated in 25 Swedish stands, and browsing damage was analysed in relation to landscape and stand factors. The proportion of browsed small (<20 cm tall) oak seedlings and other seedlings was low, and apparently a minor mortality factor. For saplings (20–130 cm tall), accumulated browsing damage was generally higher on oak than on five major competing tree species: Fraxinus excelsior, Corylus avellana, Tilia cordata, Acer platanoides and Sorbus aucuparia. Leaf removal was rare in late summer, except for rowan. The amount of cover (shelter) for ungulates near plots was positively correlated with oak browsing intensity; within plots, a high density of ash saplings may reduce browsing on oak saplings. In these forests, browsing probably retards growth of oak saplings relative to competing trees. Oak may persist as a minor stand component, but monitoring is needed to study future changes. 相似文献
8.
Floortje Vodde Kalev Jõgiste Loïc Gruson Triin Ilisson Kajar Köster John A. Stanturf 《Journal of Forest Research》2010,15(1):55-64
Natural regeneration of windthrow areas is an important issue when planning forestry measures after forest disturbances. Seedling recruitment was investigated in storm-damaged hemiboreal mixed forests in eastern Estonia. The establishment and growth of seedlings from natural regeneration was registered for tree species in soil pits and in mounds of uprooted trees in stands that were either heavily or moderately damaged. Seedling growth is expected to be better in large but shallow soil pits created by uprooted Norway spruce [Picea abies (L.) Karst.] and poorer in small but deep pits created by the hardwoods in the area, silver birch (Betula pendula Roth.) and European aspen (Populus tremula L.). The most abundant regenerating species was birch. Pits hosted larger seedling numbers than mounds, due to soil instability in mounds. Rowan (Sorbus aucuparia L.) showed significantly faster growth than the other seedling species. Norway spruce pits were preferred to pits of other species by both birch and spruce seedlings. Black alder [Alnus glutinosa (L.) J. Gaertn.] did not show a preference for pits of a certain species of uprooted tree. Both spruce and rowan preferred hardwood mounds over spruce mounds. Storm severity also affected species composition: birch predominantly occurred on pits and mounds in heavily disturbed areas, while spruce was more abundant in the moderately damaged areas. The effects of advance regeneration and surrounding stands on seedling microsite preferences should be considered in future research and subsequent management recommendations. 相似文献
9.
《Forest Ecology and Management》1998,106(1):35-44
In East Germany, there are a lot of areas covered by old pine stands. They are growing on soils, on which under natural conditions without anthropogenic impact mixed stands of oak (Quercus petraea (Matt.) Liebl.) and pine (Pinus silvestris L.), would form a natural forest. An important objective of ecological silviculture in these areas is to convert the pure pine stands into mixed oak–pine stands by using natural regeneration methods. A highly appreciated assistant in this connection is the European jay (Garrulus glandarius L.). The remarkable results of its work have been found by analyzing the natural regeneration in a few old pine stands in the forest district of Weißwasser in Saxony. Although mother trees of oak are very scarce there, natural regeneration of oak was found everywhere in the research area. The oak regeneration, undoubtedly created by the jay, amounted to at least 2000 oaks/ha. They were mainly distributed at random, while pine regeneration was aggregated in places where gaps in the pine canopy occurred. Oak regeneration was established much earlier than pine regeneration. Thus, oaks exceeded pines in age, height and diameter. The oaks were also superior to pines concerning height increment for the last three years. Thus, there is a good chance for oak to defend its prevailing role in the regeneration in the future. Probably, the next forest generation will be composed of oak and pine trees. The analysis of the quality of the oak regeneration shows that there is no substantial difference to artificially sown oak stands. This indicates that the European jay creates oak stands sufficiently both in number and quality. 相似文献
10.
Tatjana Kuznetsova Aljona LukjanovaMalle Mandre Krista Lõhmus 《Forest Ecology and Management》2011,262(2):56-64
The growth, aboveground biomass production and nutrient accumulation in black alder (Alnus glutinosa (L.) Gaertn.), silver birch (Betula pendula Roth.) and Scots pine (Pinus sylvestris L.) plantations during 7 years after planting were investigated on reclaimed oil shale mining areas in Northeast Estonia with the aim to assess the suitability of the studied species for the reclamation of post-mining areas. The present study revealed changes in soil properties with increasing stand age. Soil pH and P concentration decreased and soil N concentration increased with stand age. The largest height and diameter of trees, aboveground biomass and current annual production occurred in the black alder stands. In the 7-year-old stands the aboveground biomass of black alder (2100 trees ha−1) was 2563 kg ha−1, in silver birch (1017 trees ha−1) and Scots pine (3042 trees ha−1) stands respective figures were 161 and 1899 kg ha−1. The largest amounts of N, P, K accumulated in the aboveground part were in black alder stands. In the 7th year, the amount of N accumulated in the aboveground biomass of black alder stand was 36.1 kg ha−1, the amounts of P and K were 3.0 and 8.8 kg ha−1, respectively. The larger amounts of nutrients in black alder plantations are related to the larger biomass of stands. The studied species used N and P with different efficiency for the production of a unit of biomass. Black alder and silver birch needed more N and P for biomass production, and Scots pine used nutrients most efficiently. The present study showed that during 7 years after planting, the survival and productivity of black alder were high. Therefore black alder is a promising tree species for the reclamation of oil shale post-mining areas. 相似文献
11.
Many second growth forests have poor regeneration and in some spatial and economic context, such as post-agricultural forests, it may be beneficial to increase tree diversity. We planted seedlings of yellow birch (Betula alleghaniensis) and bur oak (Quercus macrocarpa) in strip openings of 3, 6 and 9 m width to control light. Individual mesh sleeves were used to reduce browsing pressure but they also reduced available light for seedlings: a large mesh and a small mesh sleeves were tested in each opening. Available light for seedlings ranged from 5 to 46% of full sunlight. First year growth was almost non-responsive to all treatments for both species, but birch showed strong responses during second year. Birches in the large mesh sleeve and the 9 m opening had the largest height and diameter increments, while those in the small mesh sleeve and the 3 m opening had the smallest increments. Small mesh sleeves increased the height over stem diameter ratio for both species. Treatments affected several other morphometric variables of birch but none of the oak. More time is needed to assert if bur oak can be a candidate species for enrichment planting. We recommend strip openings of 9 m width and large mesh sleeves, for protection against deer browsing, while controlling neighbouring competition, to promote artificial regeneration of hardwood species. 相似文献
12.
Arun K. Bose Mart-Jan Schelhaas Marc J. Mazerolle Frans Bongers 《European Journal of Forest Research》2014,133(3):511-523
With the increase in abandoned agricultural lands in Western Europe, knowledge on the successional pathways of newly developing forests becomes urgent. We evaluated the effect of time, soil type and dominant species type (shade tolerant or intolerant) on the development during succession of three stand attributes: above-ground biomass, stand height (HT) and stem density (SD). Additionally, we compared above-ground biomass (AGB) in natural and planted forests, using ten chronosequences (8 from the literature and 2 from this study). Both AGB and HT increased over time, whereas SD decreased. HT, SD and AGB differed among species types. For example, birch had greater HT than alder, willow and ash at a similar age and had higher SD than pine and oak at a similar age. However, birch showed lower AGB than pine. HT and AGB differed among soil types. They were higher in rich soil than in poor soils. Comparative analysis between chronosequences showed an effect of the regeneration method (natural regeneration vs plantation) on above-ground biomass. Planted sites had higher AGB than natural regeneration. Time, soil type, species and regeneration method influenced the mechanism of stand responses during secondary succession. These characteristics could be used to clarify the heterogeneity and potential productivity of such spontaneously growing temperate forest ecosystems. 相似文献
13.
14.
Recent human impact on vegetation in Takkobu, northern Japan, reconstructed from fossil pollen in lake sediments 总被引：1，自引：0，他引：1
The vegetation of Takkobu, northern Japan, has been significantly altered by land-use development following Japanese settlement
at the end of the 19th century. In order to assess the impact of human activity on vegetation dynamics in Takkobu, changes
in the vegetation composition over the last 300 years were reconstructed from fossil pollen in the sediments of Lake Takkobu.
The pollen assemblage represented broadleaved forests on the surrounding hills and alder forests found on the margin of the
wetland bordering the lake. Prior to Japanese settlement, the hillside forests consisted predominantly of oak. However, with
the onset of land-use development, a significant decline in oak relative to increasing birch was apparent, particularly after
the early 1960s. These results suggest that successive logging since the 1880s had gradually undermined the resilience of
oak. An increase of Artemisia and birch pollen also indicates an expansion of disturbed land. Since the 1960s, a large part of the broadleaved forests
in Takkobu has been converted to larch plantations, although this was not represented in the pollen data because of the underrepresentation
of larch pollen. The results of the pollen analysis have implications for forest restoration in Takkobu. The use of long-term
data allows the determination of the baseline (natural) vegetation to be restored, and also illustrates the factors affecting
present-day vegetation and how it may change in the future. 相似文献
15.
16.
Guolei Li Yong Liu Lvyi Ma Ruiheng Lv Haiqun Yu Shulan Bai Yaoyao Kang 《Frontiers of Forestry in China》2009,4(3):283-290
Direct seeding is a less expensive practice than planting and has the potential to become a viable alternative to transplanting
for afforestation and regeneration purposes. As an effective and a less costly regeneration method, aerial seeding has been
applied with several tree species. As early as 1956, Chinese people engaged in aerial seeding and stands with a total of 2.97×107 hm2 have been developed up to 2004. Our study tested whether the growth of planted Chinese pine (Pinus tabulaeformis Carr.) seedlings and its undergrowth development in northwest aspects differ from that of aerially sown seedlings on the
northern and northwestern aspects of slopes. In 2007, we collected data such as height, diameter at breast height (DBH), clear
bole height and canopy widths of trees, abundance, coverage, and frequency of shrubs and herbs from 21-year-old planted Chinese
pine stands on a northwestern aspect (PNW), aerially sown stands in a northwest aspect (ANW) and aerially sown stands in a
northern aspect (AN). Results showed that the relation of crown area and mean DBH was best fitted by a double inverse model
for the ANW and AN forests and by a quadratic model for the PNW forest. There was no difference in the growth between ANW
and AN forests, while growth was significantly higher in the PNW forest than in the ANW and AN forests. That was consistent
with the Sorenson diversity indices in the shrub and herb layers, indicating that there was a large number of the same species
in both aerially seeded stands, although their locations were different. Both the number of species in the undergrowth and
the Shannon-Wiener index in the shrub layer were higher in the PNW stands than in the ANW and AN stands. Dominant families
for all three stands were Rosaceae and Compositae in the shrub and herb layer, respectively. The dominant species for all
three stands was Spiraea pubescens in the shrub layer, while the dominant species was different from each other in the three stands. The discrepancy in diversity
and composition of species in the herb layer show that herbs are sensitive to shrubs in the three forests. High mortality
and skewed diameter distributions reflect severe competition and too high a density in the aerially seeded forests. Thus,
aerial seeding is a viable and effective regeneration technique, but management practices, such as thinning, should be applied
to these forests. 相似文献
17.
Although oaks (Quercus spp.) have historically dominated many forests in eastern North America, forest composition is changing due to anthropogenic impacts on disturbance regimes. Silvicultural practices, such as partial harvesting, are one component of management to promote oak regeneration. From 2007 to 2009 our research examined nest-site selection and nesting success for a guild of five canopy songbirds in upland mixed-oak forests in southeastern Ohio, USA. We monitored >700 nests across three state forests in both open canopy shelterwood stands harvested to approximately 50% stocking, and closed-canopy mature second-growth. Habitat attributes, including topography, canopy structure, and floristics, were measured at nest sites and random plots ?100 m from nests representing microhabitat available within the territory. Canopy songbirds selected specific topographic microclimates: Eastern Wood-pewees (Contopus virens) nested on xeric ridgetops, Blue-gray Gnatcachers (Polioptila caerulea) favored valleys, and Cerulean Warblers (Dendroica cerulea) preferred productive northeast-facing slopes. Nest sites differed among species in terms of concealment, nest support, topographic position on the slope, and basal area of trees >38 cm dbh. Four of the five focal species selected Quercus alba as the nest substrate more than twice as much as available, and three species avoided Quercus rubra. Daily survival rates of nests were negatively associated with basal area of red oak species (both Quercus velutina and Q. rubra) for several species individually and across the canopy-nesting guild. Additional factors related to success included time of season for Eastern Wood-pewees, nest age for Cerulean Warblers, and concealment and size of the support branch for Scarlet Tanagers (Piranga olivacea). In the long-term management for oak regeneration could benefit canopy songbirds, but our results indicate that white oaks, especially Q. alba, may be preferable to red oak species. 相似文献
18.
The oak (Quercus robur L.) regeneration intensity was assessed in the core area of the Białowieża National Park (BNP) in Poland with respect to
the selected ecological factors. The emphasis was placed on the response of oak regeneration to disturbances, including the
large-scale dieback of spruce stands. Defining their effect could help predicting the role of oak in naturally developing
lowland forest ecosystems in the European hemiboreal zone. The results of the study challenge the opinion that the ‘lime-oak-hornbeam
forest’ is a ‘climax’ community, confirming a very poor regeneration represented by only two saplings taller than 0.5 m per
hectare. By contrast, in spruce-dominated communities, from 49 to 848 taller saplings per hectare were found. The occurrence
of saplings was associated with discontinuous canopy of late seral stage of stands, as well as with large gaps. Most of the
best quality grown-up oak saplings developed in the immediate neighbourhood of spruce logs. The results of the research indicate
that ‘lime-oak-hornbeam forest’ (Tilio-Carpinetum) should be rather perceived as a transient community, evolved from relict, culturally modified, oak woodlands. Because spruce
had become a dominating species only after abandoning in mid-1800s the historical regime of anthropogenic disturbances (involving
frequent forest fires), the observed phenomena related to the disintegration of spruce stands had probably no precedent over
the last 500 years. To confirm whether the massive decline of spruce stands will finally result in the successful establishment
of the new canopy oak generation, both in Białowieża and other forests of hemiboreal zone, further research is needed. 相似文献
19.
The effects of species mixture on the growth and yield of mid-rotation mixed stands of Scots pine and silver birch 总被引：1，自引：0，他引：1
The effect of tree species mixture on stand volume yield and on tree-species-specific diameter and height growth rates were analysed in managed mixed stands of Scots pine (Pinus sylvestris L.) and silver birch (Betula pendula Ehrn.).Data were obtained from 14 repeatedly measured stands located in Southern Finland on mineral soil sites with varying admixture of Scots pine and silver birch. Statistical analysis was carried out for studying the effect of species mixture on the development of stand characteristics. For the analysis, the plots were categorised into three groups (plot types) according to the species dominance. In order to analyse species-specific growth rates, individual-tree mixed linear growth models for tree diameter and height growth were developed for both tree species.The results clearly show that the yield of the managed mid-rotation, mixed stands was greater for stands dominated by Scots pine than for stands dominated by birch, and the stand volume increment decreased with an increasing proportion of silver birch. Analysis of diameter and height growth by tree species revealed that the main reason for this pattern is the negative impact of birch competition on the growth of pine trees. The increase in diameter of pine was clearly hampered if the proportion of birch was high. An abundance of birch also slightly decreased the growth in height of Scots pine, although the effect was less than on diameter growth. Species mixture did not affect the diameter growth of birch but did have a significant effect on height development. Height growth of birch was considerably greater in pine-dominated stands than in birch-dominated stands. In pine-dominated mixed stands, the height growth of birch was quite close to that of dominant pine trees, and birches can endure in competition with pines for light.The results apply for even-aged and single-storey managed stands, where stocking density and structure are controlled with pre-commercial and commercial thinnings. The results are not applicable to unmanaged mixed stands undergoing self-thinning. This study provides new information on mixed stands from a silvicultural perspective, which can be applied in decisions involving the management of mixed stands. 相似文献
20.
《Scandinavian Journal of Forest Research》2012,27(3):212-220
Abstract In northern Europe, the biologically rich European aspen (Populus tremula) tends to disappear both from intensively managed and strictly protected forests, thus representing a biodiversity conservation challenge. This study describes the distribution of Aphyllophoroid fungi inhabiting aspen in a hemiboreal mixed-forest landscape where clear-cutting was usually followed by natural regeneration. In a 4-km2 area in Estonia, 181 individual forest stands and cut areas were surveyed. Sixty-one percent of the 2831 live aspen trees found were concentrated in 11% of the area. Thirty-six polypore species were recorded on aspen, with old stands and naturally created deadwood hosting most species. Among the records of 14 pre-defined aspen-specific basidiomycetes, Phellinus tremulae comprised about 95%. Six species (Ceriporiopsis aneirina, Clavicorona pyxidata, Funalia trogii, Phellinus populicola, Rigidoporus corticola, Steccherinum pseudozilingianum) were infrequent to rare, but widely distributed, inhabiting various stand-age classes, and mostly occurring outside “key habitats”. All the seven species absent are of conservation concern and frequent in Estonian old-growth forests. Thus, rotational management with natural aspen regeneration only provided habitat for some aspen-specific species. For sustaining all species, such landscapes should probably be complemented with stands managed using modified thinning and partial harvesting techniques in aspen-containing mixed stands. 相似文献