Dynamics of nitrogen (15N) in decomposing Scots pine (Pinus sylvestris) needle litter. Long-term decomposition in a Scots pine forest. VI

1988 ◽  
Vol 66 (8) ◽  
pp. 1539-1546 ◽  
Author(s):  
Björn Berg
Keyword(s):  
Pinus Sylvestris ◽  
Total Nitrogen ◽  
Scots Pine ◽  
Field Experiments ◽  
Early Stage ◽  
Fulvic Acids ◽  
Insoluble Fraction ◽  
Decomposition Process ◽  
Needle Litter ◽  
Scots Pine Forest

Labelled (15N) Scots pine (Pinus sylvestris L.) needle litter was incubated in one laboratory and two field experiments and the nitrogen dynamics was followed during the decomposition process. Release of the litter's original nitrogen began immediately after the start of the decomposition process. Simultaneously an immobilization of nitrogen to the litter took place. Very little of the actual turnover of nitrogen in the litter, which was considerable, was reflected by the dynamics of total nitrogen. The dynamics of nitrogen in the lignin fraction (acid-insoluble substance) was partly different from that of whole litter. The dynamics of total nitrogen coincided so that a net loss of total nitrogen started simultaneously both in whole litter and in the acid-insoluble fraction. As the amount of acid-insoluble substance increased in the early stage, the amount of 15N associated to this fraction increased and when a net disappearance of acid-insoluble substance started, a net release of 15N from this fraction started simultaneously. This was interpreted to mean that some of the litter's own nitrogen was transformed into compounds that could be incorporated into humic and fulvic acids (e.g., NH3 or amino acids), which were analytically recorded as acid-insoluble substance.

Decomposition of needle litter and its organic chemical components: theory and field experiments. Long-term decomposition in a Scots pine forest. III

1984 ◽  
Vol 62 (12) ◽  
pp. 2880-2888 ◽  
Author(s):  
Björn Berg ◽  
Göran I. Ågren
Keyword(s):  
Chemical Composition ◽  
Mass Loss ◽  
Scots Pine ◽  
Field Experiments ◽  
Average Rate ◽  
Chemical Components ◽  
Organic Chemical ◽  
Labile Fraction ◽  
Lignin Fraction ◽  
Scots Pine Forest

Scots pine needles were collected and field incubations were begun in the autumn of 6 consecutive years. The incubated needles were sampled three times a year and analysed for mass loss and chemical composition. The longest incubation time obtained was 1825 days. Four series of needles from a nutrition experiment (three levels of nutrient application and one control) sampled at one occasion were followed in the same way for 1448 days. The logarithm of remaining mass versus time of the pooled samples fits a linear regression well (average rate constant = 0.286 year−1, r2 = 0.963, n = 75). A higher resolution shows, however, that the decay rate decreases with time as the chemical composition changes. To better understand the decomposition process we have formulated a mathematical model for the course of mass loss as a system consisting of two fractions, a readily decomposable (labile) one and a refractory one. The mass loss from the two fractions can be direct or mass can be transferred from the refractory to the labile fraction. The model allows us to calculate the variation of the refractory fraction with time (generally there will always be some labile material in the system) and the decrease of the decomposition rate as a function of time or as a function of the concentration of the refractory fraction. We have found it possible to identify the refractory fraction both as the lignin fraction and as the nonsoluble fraction of the needles. The first identification yields a long transient response, whereas the second gives a system rapidly reaching a steady state. In both cases, the decay of the refractory material results in transfer of material to the labile fraction.

Lignin and holocellulose relations during long-term decomposition of some forest litters. Long-term decomposition in a Scots pine forest. IV

1984 ◽  
Vol 62 (12) ◽  
pp. 2540-2550 ◽  
Author(s):  
Bjorn Berg ◽  
Gunnar Ekbohm ◽  
Charles McClaugherty
Keyword(s):  
United States ◽  
Scots Pine ◽  
Field Experiments ◽  
The United States ◽  
Pine Forest ◽  
Chemical Components ◽  
Asymptotic Value ◽  
Asymptotic Values ◽  
Scots Pine Forest

We investigated the relative changes in celluloses and lignin during decomposition of leaf and needle litters and wood in field experiments. The litter came from two different forest systems: one in the United States and one in Sweden. We found that the fraction of holocellulose in the total lignocellulose (Q) during decomposition approached an asymptotic value at which the disappearance of both the chemical components proceeded at the same rate. Different litter types approached different asymptotic values of Q. Possible implications of the finding are discussed.

scholarly journals Warming and elevated ozone differently modify needle anatomy of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris)

2017 ◽  
Vol 47 (4) ◽  
pp. 488-499 ◽  
Author(s):  
Minna Kivimäenpää ◽  
Sirkka Sutinen ◽  
Hanna Valolahti ◽  
Elina Häikiö ◽  
Johanna Riikonen ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Gas Exchange ◽  
Picea Abies ◽  
Pinus Sylvestris ◽  
Norway Spruce ◽  
Scots Pine ◽  
Nitrogen Availability ◽  
Field Experiments ◽  
Needle Anatomy ◽  
Elevated Ozone

Acclimation of conifer needle anatomy to climate change is poorly understood. We studied needle anatomy, shoot gas exchange, current-year shoot length, and stem diameter growth in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) seedlings exposed to elevated ozone (1.35× to 1.5× ambient concentration) and elevated temperature (0.9–1.3 °C + ambient temperature) alone and in combination for two exposure seasons in two separate open-field experiments in central Finland. Pines grew also at two soil nitrogen levels. In spruce, warming increased mesophyll intercellular space and reduced gas exchange and shoot growth and made needles narrower and the epidermis and hypodermis thinner. In pine, warming made needles bigger, increased shoot and stem growth, stomatal row number, and proportions of vascular cylinder, phloem, and xylem and reduced the proportion of mesophyll. These responses indicate that pine benefited and spruce suffered from moderate warming. Ozone caused a thickening of epi- and hypo-dermis and a lower stomatal conductance in both species, reduced stomatal density in spruce, and increased proportions of phloem, xylem, and sclerenchyma and reduced growth in pine. Ozone responses suggest increased oxidative stress defense. Stomatal responses were affected by interactions of elevated temperature and ozone in both species. Nitrogen availability modified ozone and temperature responses, particularly in the vascular tissues in pine.

Accumulation and release of plant nutrients in decomposing Scots pine needle litter. Long-term decomposition in a Scots pine forest II

1982 ◽  
Vol 60 (8) ◽  
pp. 1561-1568 ◽  
Author(s):  
Håkan Staaf ◽  
Björn Berg
Keyword(s):  
Weight Loss ◽  
Scots Pine ◽  
Nutrient Dynamics ◽  
Pine Forest ◽  
Plant Nutrient ◽  
Pine Needle ◽  
Needle Litter ◽  
Scots Pine Forest ◽  
Net Release

Plant nutrient dynamics in decomposing needle litter were measured during a 5-year period in a Scots pine forest in central Sweden. As seen over the whole 5-year period, the nutrients were retained (to a litter weight loss of about 75%) in the order Mn < Ca < K < Mg < S < N < P. During the first 1.5 years there was a net increase of N and P whereafter a net release took place. A similar but less pronounced development could be seen for S, whereas Ca, K, Mn, and Mg were released from the start of the incubation. It is suggested that P was the most limiting element for microbial activity during this first phase. There appeared to be only little initial leaching from the litter and the different behaviours of the elements could largely be explained by their concentration in litter in relation to the needs of microorganisms and to their solubility. K and Mg were the elements that were released at rates most similar to organic matter weight loss.

Simulation of drought for a Scots pine forest (Pinus sylvestris L.) in the southern upper Rhine plain

2005 ◽  
Vol 14 (2) ◽  
pp. 143-150 ◽  
Author(s):  
Axel Wellpott ◽  
Florian Imbery ◽  
Dirk Schindler ◽  
Helmut Mayer
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Pine Forest ◽  
Scots Pine Forest ◽  
Upper Rhine

Changes in organic chemical components of needle litter during decomposition. Long-term decomposition in a Scots pine forest. I

1982 ◽  
Vol 60 (8) ◽  
pp. 1310-1319 ◽  
Author(s):  
Björn Berg ◽  
Kai Hannus ◽  
Thomas Popoff ◽  
Olof Theander
Keyword(s):  
Scots Pine ◽  
Chemical Components ◽  
Organic Chemical ◽  
Pinus Silvestris ◽  
Steryl Esters ◽  
Needle Litter ◽  
Field Incubation ◽  
Scots Pine Forest ◽  
Soluble Components

The decomposition and organic chemical changes in Scots pine (Pinus silvestris) needle litter were studied for a period of 5 years and until 75% weight loss was reached in field incubation. The changes in components such as various groups of lipophilic extractives, low-molecular carbohydrates, cyclitols, phenolic glycosides, polysaccarides, and lignin were followed. There was a great drop of sugars, steryl esters, and triglycerides during the 1st year of decomposition. Some isoprenoid alcohols, sterols, and some acids belonged to the most stable of the soluble components. Of the solid residue the arabinans decomposed rapidly, the cellulose decomposed somewhat faster than the hemicelluloses as a group, and the lignin decomposed rather slowly (about 48% in 5 years).

Temporal variation of litter decomposition in relation to simulated soil climate. Long-term decomposition in a Scots pine forest. V

1985 ◽  
Vol 63 (6) ◽  
pp. 1008-1016 ◽  
Author(s):  
P.-E. Jansson ◽  
B. Berg
Keyword(s):  
Temporal Variation ◽  
Soil Water ◽  
Scots Pine ◽  
Climatic Factors ◽  
Time Lag ◽  
Pine Forest ◽  
Soil Water Tension ◽  
Needle Litter ◽  
Scots Pine Forest ◽  
Soil Climate

Decomposition of Scots pine needle litter was studied in a Scots pine forest in central Sweden. A 6-year series with annual incubations of needle litter was used to analyse the climatic influence on the process. The original litter was of similar chemical properties between years and each year new litter was incubated, in the same way, in the autumn. Sampling took place at time intervals ranging from 1 month to 1 year. Soil climate variables such as temperature and water contents and tensions were calculated with a soil water and heat model from standard meteorological data. Decomposition rates from periods longer than 145 days were correlated with different soil climatic factors. The responses for the 1st and 2nd incubation years were not significantly different, but higher coefficients of determination (r2) were found for the 2nd year. Estimated actual evapotranspiration or soil temperature explained temporal variation of decomposition to about 70%; soil water content only or soil water tension only explained 90%. When moisture and temperature were combined, 95 and 99% of the variation could be explained for the 1st and 2nd year, respectively. When time periods down to 1 month were included, very poor fits were found with the same climate response functions. However, the relationships were improved by an inertia function which indicated a time lag of 2–3 months between soil climate and the response in decomposition rate.

Sign in / Sign up

Export Citation Format

Share Document