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1.
The intensive monitoring plots (Level II) of ICP Forests serve to examine the effects of air pollution and other stress factors
on forest condition, including tree vitality. However, tree vitality cannot be measured directly. Indicators, such as tree
growth or crown transparency, may instead be used.
Tree growth processes can be ranked by order of importance in foliage growth, root growth, bud growth, storage tissue growth,
stem growth, growth of defence compounds and reproductive growth. Under stress photosynthesis is reduced and carbon allocation
is altered. Stem growth may be reduced early on as it is not directly vital to the tree.
Actual growth must be compared against a reference growth, such as the growth of trees without the presumed stress, the growth
of presumed healthy trees, the growth in a presumed stress-free period or the expected growth derived from models.
Several examples from intensive monitoring plots in Switzerland illustrate how tree-growth reactions to environmental stresses
may serve as vitality indicator. Crown transparency and growth can complement each other. For example, defoliation by insects
becomes first visible in crown transparency while stem growth reaction occurs with delay. On the other hand, extreme summer
drought as observed in large parts of Europe in 2003 affects stem growth almost immediately, while foliage reduction becomes
only visible months later.
Residuals of tree growth models may also serve as indicators of changed environmental conditions. Certain stresses, such as
drought or insect defoliation cause immediate reactions and are not detectable in five-year growth intervals. Therefore, annual
or inter-annual stem growth should be assessed in long-term monitoring plots.
An erratum to this article can be found at 相似文献
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3.
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4.
Thomas M. James 《Forest Ecology and Management》2011,262(4):629-636
This study sought to clarify the recruitment dynamics and growth of Siberian larch (Larix sibirica) and Siberian spruce (Picea obovata) in relation to changing temperatures in northern Mongolia. These tree species are the primary forest species found in the closed-canopy boreal forest of north-central Mongolia. Mongolia’s boreal forests exist along the southern terminus of the Siberian boreal system in both pure and mixed species stands. I collected tree cores and cross-sections as well as site and tree stature parameters from 118 forest plots in the Darhad valley of north-central Mongolia. Principle components analysis of 130 L. sibirica tree ring series informed the construction of two composite chronologies for this species. A chronology for P. obovata was developed using 24 tree ring series. Correlation analysis between tree ring indices and temperature data showed two distinct growth signals: a positive response to growing season temperatures was exhibited by one L. sibirica chronology and a negative response to spring temperatures was exhibited by a second L. sibirica chronology. The P. obovata chronology exhibited strong negative correlations with mean monthly and mean maximum monthly growing season temperatures. Multiple analyses of variance (MANOVA) indicated that tree stature (dbh, height) and site parameters (latitude, longitude, slope, aspect, elevation) did not significantly predict growth response or species. Forest recruitment events appear episodic for both species. Synchronous establishment of saplings, based on approximate root collar age, suggests an initial floristic model for mixed composition stands likely due to supra-annual variations of fire, land-use and climate. Forest management activities in the region should consider the diverging growth response to temperature shown here by prioritizing protection forests and the various ecosystem services provided by forests in arid ecosystems. In addition, promoting selection harvests over clear-felling would maximize future alternatives under conditions of rapidly changing climate. Care should be taken in new forest management planning activities until adequate information exists on the likely trajectory of this system due to climate-induced forest change. 相似文献
5.
C.W. Woodall C.M. Oswalt J.A. Westfall C.H. Perry M.D. Nelson A.O. Finley 《Forest Ecology and Management》2010
The lack of objective tree species lists hinders the assessment of climate change effects on tree species distributions. The goal of this study was to develop and evaluate criteria for selecting tree species used in large-scale tree migration monitoring efforts. The results of this study indicate that tree migration conclusions are highly dependant on the species selected for examination. It was found that tree species’ median latitudes or forecasted future areas provided objective criteria for development of species lists for migration hypothesis testing with the latter being insensitive to simulation error. Furthermore, only 10–15 of the top species, in terms of high median latitudes or loss in forecasted future area, are needed to maximize the sensitivity of a migration index. The use of such criteria in this study indicated a northward shift of sensitive tree populations of 27 km. It is suggested that examining species only the most likely to migrate serves as an objective starting point for migration detection. In contrast, the inclusion of all tree species commonly observed in large-scale forest inventories can obfuscate migration detection with tree species that have little ecological reason to immediately migrate in a changing climate. 相似文献
6.
运用多目标线性规划的方法,以定量分析为核心,以生态、经济、社会效益最大为目标,建立起衡阳县长防林体系林种、树种、林分结构优化的数学模型,调整了林种、树种、林分结构,为该县林业发展规划提供了科学依据。 相似文献
7.
根据1976年播后出苗率和成苗率调查,1987--1990年油松毛虫灾害对油松林分的影响,及1991年和2003年丁营飞播区森林资源清查资料,通过调查数据对比分析,丁营飞播区播后林分变化规律,符合近自然林业发展规律。面向整个丁营飞播区生态系统,依据近自然林业经营理念,研究丁营飞播区经营管理措施,实现林业经营目标的最大化。 相似文献
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9.
We examined the relationship between landform types and riparian forest structure and succession in second-growth stands along mid order streams in the Cascade Mountains, Washington, USA. We sampled tree, sapling, seedling, and shrub characteristics across a range of fluvial geomorphic surfaces, which were classified into four landform classes, including low floodplain, high floodplain, terrace and hillslope. Landform classification was based on topographic characteristics, position relative to the stream channel, and estimated flood frequency. Statistical analyses using generalized estimating equations (GEE) showed that landform exerted a strong influence on the distribution and abundance of conifer and deciduous species and of different tree life stages. The floodplain landforms were characterized by initial disturbance from timber harvest, and ongoing fluvial disturbance, which favored the establishment of deciduous communities dominated by red alder (Alnus rubra) and maintenance of early successional riparian stands. In contrast, the terrace and hillslope landforms were also subject to timber harvest as the stand initiating agent but were unaffected by fluvial disturbance. However, based on differences in species distribution, we infer that forest structure on these two landforms differed from one another as a result of differences in soil moisture levels. Terraces and hillslopes were found to have high conifer tree abundance, but frequency of younger conifers was higher on hillslopes. Deciduous tree reproduction was very low on terraces and hillslopes. Our results also suggest that conifer recruitment in these second-growth riparian forests may be more successful on soil substrates than on coarse woody debris. We propose that the interplay between the disturbance regime (including type, frequency and intensity) and soil moisture conditions played an important role in influencing the course of riparian succession, present stand structure, and future successional trajectories and these were the primary mechanisms driving vegetation differences among landforms. 相似文献
10.
Forests contain the world's largest terrestrial carbon stocks, but in seasonally dry environments stock stability can be compromised if burned by wildfire, emitting carbon back to the atmosphere. Treatments to reduce wildfire severity can reduce emissions, but with an immediate cost of reducing carbon stocks. In this study we examine the tradeoffs in carbon stock reduction and wildfire emissions in 19 fuels-treated and -untreated forests burned in twelve wildfires. The fuels treatment, a commonly used thinning ‘from below’ and removal of activity fuels, removed an average of 50.3 Mg C ha−1 or 34% of live tree carbon stocks. Wildfire emissions averaged 29.7 and 67.8 Mg C ha−1 in fuels treated and untreated forests, respectively. The total carbon (fuels treatment plus wildfire emission) removed from treated sites was 119% of the carbon emitted from the untreated/burned sites. However, with only 3% tree survival following wildfire, untreated forests averaged only 7.8 Mg C ha−1 in live trees with an average quadratic mean tree diameter of 21 cm. In contrast, treated forest averaged 100.5 Mg C ha−1 with a live tree quadratic mean diameter of 44 cm. In untreated forests 70% of the remaining total ecosystem carbon shifted to decomposing stocks after the wildfire, compared to 19% in the fuels-treated forest. In wildfire burned forest, fuels treatments have a higher immediate carbon ‘cost’, but in the long-term may benefit from lower decomposition emissions and higher carbon storage. 相似文献
11.
Effects on stream water chemistry and forest vitality after whole-catchment application of dolomite to a forest ecosystem in southern Norway 总被引:7,自引:0,他引:7
Atle Hindar Richard F. Wright Petter Nilsen Thorjrn Larssen Rolf Hgberget 《Forest Ecology and Management》2003,180(1-3):509-525
An acidified, 0.8 km2 coniferous-forested catchment was limed with 3 t ha−1 of coarse-grained dolomite powder in September 1994. The liming resulted in an immediate change in runoff water chemistry relative to the stream of an adjacent reference catchment. pH, calcium, magnesium and acid neutralising capacity (ANC) increased and inorganic Al decreased after liming. Potential favourable water quality for sensitive organisms remained relatively constant over the post-liming period (7 years), and model simulations indicate that adequate water quality may last for an additional 40–50 years. NO3 concentrations showed no significant change due to liming. A significant increasing trend in TOC was attributed to liming. Concentrations of Cd, Co, Fe, Mn, Ni and Zn were lower in the limed stream than in the reference stream during a period of 3 years after liming, whereas concentrations of As, Cu, and Pb were not significantly different. Steep slopes, thin soils, high amounts of precipitation and thus dominance of surface and subsurface flow in this catchment may explain the rapid response in runoff. During the first 6 years after liming there have been no significant effects on tree growth and vitality (crown density and crown colour). This experiment shows that liming of forested catchments may be a viable method to obtain long-term improvement in water quality and potential positive effects for acid-sensitive aquatic organisms. 相似文献
12.
Sabine Augustin Jan Evers Hans-Peter Dietrich Johannes Eichhorn Thomas Haussmann Regina Icke Ansgar Isenberg Wolfgang Lux Monica Musio Hans Pretzsch Winfried Riek Thomas Rötzer Bernd Schultze Andreas Schulze Jörg Schröder Walter Seidling Nicole Wellbrock Klaus von Wilpert Barbara Wolff 《European Journal of Forest Research》2005,124(4):251-260
In the 1970s unexpected forest damages, called “new type of forest damage” or “forest decline”, were observed in Germany and
other European countries. The Federal Republic of Germany and the German Federal States implemented a forest monitoring system
in the early 1980s, in order to monitor and assess the forest condition. Due to the growing public awareness of possible adverse
effects of air pollution on forests, in 1985 the ICP Forests was launched under the convention on long-range transboundary
air pollution (CLRTAP) of the United Nations Economic Commission for Europe (UN-ECE). The German experience in forest monitoring
was a base for the implementation of the European monitoring system. In 2001 the interdisciplinary case study “concept and
feasibility study for the integrated evaluation of environmental monitoring data in forests”, funded by the German Federal
Ministry of Education and Research, concentrated on in-depths evaluations of the German data of forest monitoring. The objectives
of the study were: (a) a reliable assessment of the vitality and functioning of forest ecosystems, (b) the identification
and quantification of factors influencing forest vitality, and (c) the clarification of cause-effect-relationships leading
to leaf/needle loss. For these purposes additional data from external sources were acquired: climate and deposition, for selected
level I plots tree growth data, as well as data on groundwater quality. The results show that in particular time series analysis
(crown condition, tree growth, and tree ring analysis), in combination with climate and deposition are valuable and informative,
as well as integrated evaluation of soil, tree nutrition and crown condition data. Methods to combine information from the
extensive and the intensive monitoring, and to transfer process information to the large scale should be elaborated in future.
相似文献
Sabine AugustinEmail: |
13.
《Scandinavian Journal of Forest Research》2012,27(3):214-226
Abstract The quantitative effect of pine-dominated edge stands in southern Finland on the density and growth of pine saplings was addressed in the study. The cumulative effect of a mature edge stand on the development of a pine sapling stand with variable cutblock sizes was also estimated. The data were acquired from 10 study sites with a Scots pine sapling stand with a current dominant height of 1–6 m and an adjoining middle-aged to mature edge stand dominated by Scots pine. Tree level models were constructed to describe and simulate the structure and development of the sapling stands. The results indicated that dividing an average regeneration area (2 ha) into smaller cutblock units (1.0–0.5 ha) appreciably increased the edge stand effect. Total stand volume growth was 6% lower on 1 ha cutblocks, and 31% lower on 0.5 ha blocks, than on 2 ha blocks. 相似文献
14.
Karl Heinz Mellert Jörg Prietzel Ralf Straussberger Karl Eugen Rehfuess Hans Peter Kahle Pedro Perez Heinrich Spiecker 《European Journal of Forest Research》2008,127(6):507-524
Height growth of 19 Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) stands in Germany, Austria and Finland, for which long-term records of foliar nutrient levels were available, was assessed
retrospectively by stem analyses and compared with data from regionally applied yield tables as references. Gridded historical
time series of monthly temperature and precipitation were used to characterise the meteorologic conditions at the sampling
sites. Climate parameters were tested against height growth in period 1950–2000, and needle N content was tested against height
growth for the periods where N measurements were available by means of graphical comparison, as well as simple and multiple
regression analyses with the aim to get evidence for causes of possible growth acceleration. Trends of referenced height increment
of six out of nine Scots pine stands in Germany were positive during the observation period, and improved N nutrition appeared
to be the most important driving factor for this growth acceleration. The variation of precipitation—exhibiting no consistent
and uniform long-term temporal trend during the observation period—in contrast seems to be mainly responsible for the interannual
fluctuation of height growth. We were not able to detect any general statistical influence of temperature parameters on height
growth, although they generally increased. The referenced height growth of three Finnish pine stands slightly decreased during
the observation period and there was no indication of a significant improvement of their N supply. Among four Norway spruce
stands investigated in Germany and Austria, referenced height increment also increased in three cases; there was again some
evidence that improved N nutrition was the stimulating factor. At three study sites in Finland, however, referenced height
growth of this species decreased at least from 1985 onwards, whereas mostly no significant trends in N nutrition or precipitation
were identified. These differences observed between species and regions are discussed in detail. 相似文献
15.
Tree growth and carbon dynamics are important issues especially in the context of climate change. However, we essentially
lack knowledge about the effects on carbon dynamics especially in mixed stands. Thus, the objective of this study was to test
the effects of climatic changes on the above and below ground carbon dynamics of a mixed stand of Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) by means of scenario simulations. To account for the typical tree interactions in a mixed-species stand a spatial explicit
tree growth model based on eco-physiological processes was applied. Three different climate scenarios considering altered
precipitation, temperature, and radiation were calculated for an unthinned and a thinned stand. The results showed significant
changes of above and belowground biomass over time, especially when temperature and radiation were increased additionally
to decreased precipitation. The reduction in biomass increments of Norway spruce were more attenuated above than below ground.
In contrast, the results for beech were the opposite: The belowground increments were reduced more. These results suggest
a shift in the species contribution to above and belowground biomass under dryer and warmer conditions. Distinct effects were
also found when thinned and unthinned stands were compared. A reduced stand density changed the proportions of above and below
ground carbon allocation. As a main reason for the changed growth reactions the water balance of trees was identified which
lead to changed biomass allocation pattern.
This article belongs to the special issue “Growth and defence of Norway spruce and European beech in pure and mixed stands”. 相似文献
16.
Eva Chumanová Dušan Romportl Ludmila Havrdová Daniel Zahradník Vítězslava Pešková Karel Černý 《Scandinavian Journal of Forest Research》2019,34(4):254-266
Ash dieback, caused by the ascomycete fungus Hymenoscyphus fraxineus, has been rapidly expanding across Europe during the last two decades, posing a considerable threat to native ash populations. In this study, we applied regression-based models trained by field data, in conjunction with geographic information systems, to produce spatial predictions of ash dieback severity and environmental suitability for the disease in Czech forests. A model of actual ash dieback severity relates disease extent to silvicultural and environmental characteristics of forest stands and their neighbourhood, while a model of environmental suitability for the disease quantifies the relative susceptibility of sites to the disease, independent of the current silvicultural characteristics. The final predictive maps suggested that fertile lowlands and humid areas bordering Poland and Slovakia were the most endangered regions. Areas at the lowest risk of damage were concentrated in dry areas and in highland and mountain areas in the western part of the country, usually with poor soils on acid bedrock. Predictions of actual disease severity are an effective tool for guiding the current management of infested stands whereas predicting environmental suitability is useful for making long-term strategic decisions, e.g. identifying areas where future ash regeneration and cultivation may be unsuccessful. 相似文献
17.
In the western Mediterranean region of Catalonia (NE Spain), during the last 20 years of the 20th century, the range of many forest bird species has expanded. Our objective was to characterize the roles of (a) spatial population processes (related to dispersal), (b) changes in forest structure (due to forest maturation and management), and (c) landscape composition (resulting from afforestation and fires) in the range expansion of these bird species at the landscape scale (10 × 10 km). After correcting for the differences in sampling effort, colonizations appeared to be more likely near areas in which the species had been present in the 1980s. Patterns of the range expansion were also strongly associated with forest maturation, which seems to affect the spatial arrangement of birds at multiple scales. Changes in forest landscape composition due to afforestation and fires were minor determinants of range changes, and forest management did not seem to prevent range expansion at the spatial scale studied. Colonization events appeared to be driven primarily by landscape changes occurring in nearby localities rather than within the colonized locations themselves, presumably because of source–sink dynamics and connectivity patterns. Our results showed that in Catalonia, at a landscape scale, the impact of forest management on forest bird communities is much smaller than the impact of the widespread maturation of forests following a large-scale decline in traditional uses. 相似文献
18.
C.W. Woodall C.M. Oswalt J.A. Westfall C.H. Perry M.D. Nelson A.O. Finley 《Forest Ecology and Management》2009
Changes in tree species distributions are a potential impact of climate change on forest ecosystems. The examination of tree species shifts in forests of the eastern United States largely has been limited to simulation activities due to a lack of consistent, long-term forest inventory datasets. The goal of this study was to compare current geographic distributions of tree seedlings (trees with a diameter at breast height ≤2.5 cm) with biomass (trees with a diameter at breast height > 2.5 cm) for sets of northern, southern, and general tree species in the eastern United States using a spatially balanced, region-wide forest inventory. Compared to mean latitude of tree biomass, mean latitude of seedlings was significantly farther north (>20 km) for the northern study species, while southern species had no shift, and general species demonstrated southern expansion. Density of seedlings relative to tree biomass of northern tree species was nearly 10 times higher in northern latitudes compared to southern latitudes. For forest inventory plots between 44° and 47° north latitude where southern tree species were identified, their biomass averaged 0.46 tonnes/ha while their seedling counts averaged 2600 ha−1. It is hypothesized that as northern and southern tree species together move northward due to greater regeneration success at higher latitudes, general species may fill their vacated niches in southern locations. The results of this study suggest that the process of northward tree migration in the eastern United States is currently underway with rates approaching 100 km/century for many species. 相似文献
19.
Calibrating and testing a gap model for simulating forest management in the Oregon Coast Range 总被引:1,自引:0,他引:1
Robert J. Pabst Matthew N. Goslin Steven L. Garman Thomas A. Spies 《Forest Ecology and Management》2008
The complex mix of economic and ecological objectives facing today's forest managers necessitates the development of growth models with a capacity for simulating a wide range of forest conditions while producing outputs useful for economic analyses. We calibrated the gap model ZELIG to simulate stand-level forest development in the Oregon Coast Range as part of a landscape-scale assessment of different forest management strategies. Our goal was to incorporate the predictive ability of an empirical model with the flexibility of a forest succession model. We emphasized the development of commercial-aged stands of Douglas-fir, the dominant tree species in the study area and primary source of timber. In addition, we judged that the ecological approach of ZELIG would be robust to the variety of other forest conditions and practices encountered in the Coast Range, including mixed-species stands, small-scale gap formation, innovative silvicultural methods, and reserve areas where forests grow unmanaged for long periods of time. We parameterized the model to distinguish forest development among two ecoregions, three forest types and two site productivity classes using three data sources: chronosequences of forest inventory data, long-term research data, and simulations from an empirical growth-and-yield model. The calibrated model was tested with independent, long-term measurements from 11 Douglas-fir plots (6 unthinned, 5 thinned), 3 spruce-hemlock plots, and 1 red alder plot. ZELIG closely approximated developmental trajectories of basal area and large trees in the Douglas-fir plots. Differences between simulated and observed conifer basal area for these plots ranged from −2.6 to 2.4 m2/ha; differences in the number of trees/ha ≥50 cm dbh ranged from −8.8 to 7.3 tph. Achieving these results required the use of a diameter-growth multiplier, suggesting some underlying constraints on tree growth such as the temperature response function. ZELIG also tended to overestimate regeneration of shade-tolerant trees and underestimate total tree density (i.e., higher rates of tree mortality). However, comparisons with the chronosequences of forest inventory data indicated that the simulated data are within the range of variability observed in the Coast Range. Further exploration and improvement of ZELIG is warranted in three key areas: (1) modeling rapid rates of conifer tree growth without the need for a diameter-growth multiplier; (2) understanding and remedying rates of tree mortality that were higher than those observed in the independent data; and (3) improving the tree regeneration module to account for competition with understory vegetation. 相似文献
20.
Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest
increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, China were studied by stepwise
regression procedure and grey system theories and methods. A regression model reflecting the correlation between the height
increment of poplar protection forest and climatic factor was developed. The order of grey relevance for the effect of climatic
factors on the height increment of poplar protection forest is: light>water>heat, and it could be interpreted that the poplar
increment was mainly influenced by light factor, water factor, and heat factor. This result will provide scientific basis
for the intensive cultivation and regenration of the poplar protection forest in riverbank field in similar regions in China.
Foundation item: This study was supported by the National Natural Science Foundation of China (No. 30270250), and a key direction project
(No. C12MC-SCMS013)
Biography: LI Hai-mei (1975-), female, Ph. D, department of Landscpe Architecture. Art. Laiyang Agricultural College, Shandong Qingdao
266109, P. R. China.
Responsible editor: Song Funan 相似文献