Ecological gradients of boreal forests in South Finland: an ordination test of Cajander's forest site type theory

Vegetatio ◽  
1987 ◽  
Vol 68 (3) ◽  
pp. 145-156 ◽  
Author(s):  
Tapani Lahti ◽  
Risto A. V�is�nen
Keyword(s):  
Type Theory ◽  
Boreal Forests ◽  
Forest Site ◽  
Ecological Gradients ◽  
Site Type

Diversity of polyporous fungi (Polyporaceae) in northern boreal forests: effects of forest site type and logging intensity

2004 ◽  
Vol 19 (2) ◽  
pp. 152-163 ◽  
Author(s):  
Anna-liisa. Sippola ◽  
Maarit Similä ◽  
Mikko Mönkkönen ◽  
Jukka Jokimäki
Keyword(s):  
Boreal Forests ◽  
Forest Site ◽  
Site Type

scholarly journals Benchmarking the Retrieval of Biomass in Boreal Forests Using P-Band SAR Backscatter with Multi-Temporal C- and L-Band Observations

2019 ◽  
Vol 11 (14) ◽  
pp. 1695 ◽  
Author(s):  
Cartus ◽  
Santoro ◽  
Wegmüller ◽  
Rommen
Keyword(s):  
Boreal Forests ◽  
Forest Site ◽  
Above Ground Biomass ◽  
Retrieval Accuracy ◽  
Ground Biomass ◽  
Multi Temporal ◽  
L Band ◽  
Semi Empirical ◽  
Relative Root ◽  
Band Image

The planned launch of a spaceborne P-band radar mission and the availability of C- and L-band data from several spaceborne missions suggest investigating the complementarity of C-, L-, and P-band backscatter with respect to the retrieval of forest above-ground biomass. Existing studies on the retrieval of biomass with multi-frequency backscatter relied on single observations of the backscatter and were thus not able to demonstrate the potential of multi-temporal C- and L-band data that are now available from spaceborne missions. Based on spaceborne C- and L-band and airborne P-band images acquired over a forest site in southern Sweden, we investigated whether C- and L-band backscatter may complement retrievals of above-ground biomass from P-band. To this end, a retrieval framework was adopted that utilizes a semi-empirical model for C- and L-bands and an empirical parametric model for P-band. Estimates of above-ground biomass were validated with the aid of 20 m-diameter plots and a LiDAR-derived biomass map with 100 m × 100 m pixel size. The highest retrieval accuracy when not combining frequencies was obtained for P-band with a relative root mean square error (RMSE) of 30% at the hectare scale. The retrieval with multi-temporal L- and C-bands produced errors of the order of 40% and 50%, respectively. The P-band retrieval could be improved for 4% when using P-, L-, and C-bands jointly. The combination of C- and L-bands allowed for retrieval accuracies close to those achieved with P-band. A crucial requirement for achieving an error of 30% with C- and L-bands was the use of multi-temporal observations, which was highlighted by the fact that the retrieval with the best individual L-band image was associated with an error of 61%. The results of this study reconfirmed that P-band is the most suited frequency for the retrieval of above-ground biomass of boreal forests based on backscatter, but also highlight the potential of multi-temporal C- and L-band imagery for mapping above-ground biomass, for instance in areas where the planned ESA BIOMASS P-band mission will not be allowed to acquire data.

scholarly journals Long-term dynamics of monoterpene synthase activities, monoterpene storage pools and emissions in boreal Scots pine

2018 ◽  
Author(s):  
Anni Vanhatalo ◽  
Andrea Ghirardo ◽  
Eija Juurola ◽  
Jörg-Peter Schnitzler ◽  
Ina Zimmer ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Scots Pine ◽  
Boreal Forests ◽  
Intraspecific Variability ◽  
Dry Weight ◽  
Forest Site ◽  
Plant Variation ◽  
Needle Age ◽  
Monoterpene Synthase ◽  
Storage Pools

Abstract. Seasonal variations in monoterpene emissions from Scots pine (Pinus sylvestris) are well documented, and emissions are often shown to follow the incident temperatures due to effects on compound volatility. Recent studies have indicated a link between monoterpene emissions and physiological drivers such as photosynthetic capacity during needle development. The complex interplay between the dynamic changes in the biosynthetic capacity to produce monoterpenes and the temperature-dependent evaporation process of volatiles from internal storage reservoirs has not yet been studied under field conditions. Here, we analysed the relationships between needle monoterpene synthase activities, endogenous monoterpene storage pools and monoterpene emissions of needles in two consecutive years at a boreal forest site in Finland. The results showed changes in the monoterpene synthase activity of needles, linked to seasonality and needle ontogenesis, while the pool of stored monoterpenes (about 0.5 % of dry weight) did not change considerably as a function of needle aging. Monoterpene emissions did not correlate directly with enzyme activity or the storage pool size. We observed notably high plant-to-plant variation in the biosynthesis rates of individual monoterpenes, which did not reflect the storage compound mixture. The enzyme activity producing δ-3-carene was only present in the first months after needle flushing, and decreased with needle age, whereas δ-3-carene was abundant in the endogenous monoterpene pool and dominated the needle emissions. This study emphasizes the seasonal, developmental and intraspecific variability of monoterpene biosynthesis and storage, and calls for more in-depth analyses to reveal how such complex interaction affects monoterpene emissions from pine needles in boreal forests.

scholarly journals Characteristics of chosen biometric features of European ash (Fraxinus excelsior L.) due to the age of trees and the forest site type

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Krzysztof Turczański ◽  
Katarzyna Kaźmierczak ◽  
Bogna Zawieja
Keyword(s):  
Strong Relationship ◽  
Floodplain Forest ◽  
Analysis Of Covariance ◽  
Forest Site ◽  
Diameter At Breast Height ◽  
Site Type ◽  
Breast Height ◽  
Biometric Features ◽  
European Ash ◽  
Site Types

The dieback of European ash contributes the disappearance of the species from the typical ash sites such as floodplain forests or alder-ash forests. The species occurs more often in moist broadleaved forests and fresh broadleaved forests. Therefore, the main objective of our study was to determine the influence of ash age and the forest site type on the chosen biometric features of dominant and codominant trees. We also aimed to compare the sizes of European ash growing in optimal forest site types with less fertile ones, where it does not occur as the main species. We collected the empirical material from 25 plots representing 4 forest site types: fresh broadleaved forest, moist broadleaved forest, floodplain forest, and alder-ash forest. The research plots were located in the Babki, Konstantynowo, and Łopuchówko Forest Districts, western Poland. The age of ash varied from 52 to 144 years. On each plot, we measured a tree height and a diameter at breast height of 15 dominant and codominant ash trees. Subsequently, we used measured features to calculate the volume of each tree. We carried out the analysis of covariance of diameter at breast height, height, and volume. The analysis showed the strong relationship of examined features with the age of the species and the forest site type. Furthermore, our results indicated the underestimation of the growth possibilities of European ash in fresh broadleaved forest and moist broadleaved forest. In these sites, ash achieved similar sizes in comparison to optimal forest site types, i.e. floodplain forest and alder-ash forest. This result cannot be omitted in forestry practice, especially in silviculture, which should aim to support the natural regeneration of European ash in differentiated site conditions. Keywords: European ash, forest site type, age of a tree, biometric features

scholarly journals Ambient sesquiterpene concentration and its link to air ion measurements

2006 ◽  
Vol 6 (6) ◽  
pp. 13165-13224 ◽  
Author(s):  
B. Bonn ◽  
A. Hirsikko ◽  
H. Hakola ◽  
T. Kurtén ◽  
L. Laakso ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Boreal Forests ◽  
Seasonal Pattern ◽  
Ambient Air ◽  
High Reactivity ◽  
High Time Resolution ◽  
Forest Site ◽  
Proton Affinities ◽  
Air Ions ◽  
Ion Size

Abstract. Ambient air ion size distributions have been measured continuously at the Finnish boreal forest site in Hyytiälä since spring 2003. In general, these measurements show a maximum of air ions below 1.0 nm in diameter. But this physical characterization does not provide any information about the ion's chemical composition, which is one key question regarding the explanation of nucleation events observed. In this study we propose a link of the observed maximum of negative air ions between 0.56 and 0.75 nm to the so-called stabilised Criegee biradical, formed in the reaction of biogenic sesquiterpenes with ozone and predominantly destroyed by its reaction with ambient water vapour. Calculations of the electron and proton affinities of 120 kJ mol−1 (1.24 eV) and of 960 kJ mol−1 support this link. Other possible candidates such as sulphuric acid derived clusters are unable to explain the observations made. By using this approach, we are able to calculate the ambient concentration of sesquiterpenes at the air ion instrument inlet with a high time resolution on the daily and seasonal scale. The estimated concentration is found to reveal the same seasonal pattern as emission measurements conducted at shoot level. As expected for biogenic VOCs, the concentration is obtained highest during summer (maximum values of about 100 pptv) and smallest during winter (minimum less than 1 pptv). Because of the sesquiterpenes high reactivity and its low ambient concentrations, this approach can be a first step in understanding their emission and their impact on atmospheric chemistry in more detail. The findings presented are highly relevant for emission budgets too, since boreal forests are extended over large areas of the globe.

scholarly journals HEIGHT INCREMENT OF NATURALLY REGENERATED YOUNG FOREST STANDS OF SCOTS PINE PINUS SYLVESTRIS L. IN MYRTILLOSA FOREST SITE TYPE

2015 ◽  
Author(s):  
Olga MIEZĪTE ◽  
Ineta EGLĪTE ◽  
Solveiga LUGUZA ◽  
Imants LIEPA
Keyword(s):  
Health Status ◽  
Scots Pine ◽  
Initial Density ◽  
Stand Density ◽  
Forest Site ◽  
Height Increment ◽  
Forest Stands ◽  
Annual Increment ◽  
Site Type ◽  
Young Forest

One of the most important stand productivity and competition indicators is height annual increment, which is affected by various factors such as soil preparation, initial density as well as various management risk factors. Empirical material for the research was collected in the northern part of Latvia. In four pure Scots pine stands in Myrtillosa forest site type 29 circular plots tree diameter, height and the last five years annual height increment was measured and visual state of health was described. The aim of this research is to analyse Scots pine height annual increment in naturally regenerated young forest stands in Myrtillosa site type forest stands and to give an evaluation of the impact of the initial stand density and the health status on height growth. The mean height increment in studied stands is 0.26 ± 0.009 m and the average periodical increment is 0.37 ± 0.042 m. The annual height increment has been in the height range from 0.23 to 0.53 m. Initial stand density affects the annual height increment significantly. In the stand with an initial density of 5770 ± 961 trees the height increment during the last five years has risen by 36%, but in stand with initial density of 12,650 ± 1,581 trees (P = 51.8 % and R = 6.0 %) the height increment during the five-years period has increased by only 12 %. The tree health status does not affect the tree height increment significantly.

scholarly journals SOME PRINCIPLES OF FOREST SITE-TYPE CLASSIFICATION

1951 ◽  
Vol 27 (2) ◽  
pp. 157-163 ◽  
Author(s):  
A. Kabzems
Keyword(s):  
Forest Site ◽  
Site Type ◽  
Type Classification

scholarly journals Simple proxies for estimating the concentrations of monoterpenes and their oxidation products at a boreal forest site

2016 ◽  
Author(s):  
Jenni Kontkanen ◽  
Pauli Paasonen ◽  
Juho Aalto ◽  
Jaana Bäck ◽  
Pekka Rantala ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Transfer Reaction ◽  
Aerosol Particles ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
Forest Site ◽  
Oxidation Processes ◽  
Direct Measurements ◽  
Boreal Environment

Abstract. The oxidation products of monoterpenes likely have a crucial role in the formation and growth of aerosol particles in boreal forests. However, the continuous measurements of monoterpene concentrations are usually not available in decadal time scales, and the direct measurements of the concentrations of monoterpene oxidation product are so far scarce. In this study we developed proxies for the concentrations of monoterpenes and their oxidation products at a boreal forest site in Hyytiälä, southern Finland. For deriving the proxies we used the monoterpene concentration measured with a proton transfer reaction mass spectrometer (PTR-MS) during 2006–2013. Our proxies for the monoterpene concentration take into account the temperature-controlled emissions from the forest ecosystem, the dilution caused by the mixing within the boundary layer, and different oxidation processes. All the versions of our proxies captured the seasonal variation of the monoterpene concentration, the typical proxy-to-measurements ratios being between 0.8 and 1.3 in summer and between 0.6 and 2.6 in winter. In addition, the proxies were able to describe the diurnal variation of the monoterpene concentration rather well, especially in summer months. By utilizing one of the proxies, we calculated the concentration of oxidation products of monoterpenes by considering their production in the oxidation and their loss due to condensation on aerosol particles. The concentration of oxidation products was found to have a clear seasonal cycle with the maximum in summer and the minimum in winter. The concentration of oxidation products was lowest in the morning or around noon and highest in the evening. In the future, our proxies for the monoterpene concentration and their oxidation products can be used, for example, in the analysis of new particle formation and growth in boreal environment.

scholarly journals Development and renewal-conditions of dune pine forests second growth in the lichen and cowberry site type in Southwest Estonia

2008 ◽  
Vol 49 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Kadri Kõresaar ◽  
Priit Kõresaar ◽  
Malle Mandre
Keyword(s):  
Natural Regeneration ◽  
Unit Area ◽  
Dry Mass ◽  
Pine Forest ◽  
Pine Forests ◽  
Primary Data ◽  
Forest Site ◽  
Height Increment ◽  
Site Type ◽  
Second Growth

Edela-Eesti luitemetsade järelkasvu arengust ning uuenemistingimustest sambliku ja pohla kasvukohatüübis On the southwestern coast of Estonia dune pine forest covers approximately 3000 hectares. This area includes coastal pine forests. The dune pine forest natural renewal in Southwest Estonia is the object of research. The natural regeneration of Scots pine (Pinus sylvestris L.) at the cowberry site type and at the lichen site type are observed. The necessary observations were made and primary data were collected in 1999-2006 from 28 sample plots, wherefrom 16 were situated at the lichen and 12 at the cowberry site type. The aim of the present study was to find out how old stand and forest site type influences the growth of second growth (height, height increment, age and number of trees per unit area) and its morphological parameters (length of needles and shoots and their dry mass).

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