Papers by Johan Holmqvist
Mineralogical Magazine, 1998
Managing Forest Ecosystems, 2002
It is important to find and develop forest management strategies that do not result in the deplet... more It is important to find and develop forest management strategies that do not result in the depletion of soil nutrient pools and at the same time are financially competitive in relatively short-term, 1–2 rotations. Mixed-species stands, which combine the elements of fast growing, highly productive softwood and more slowly growing, high quality hardwood, appear to be an interesting alternative in this respect, one worthy of further investigation. Among the mixtures of trees tried out in southern Swedish forestry thus far the Norway spruce/oak-system developed by Erik St”l and his heirs at their estate in Jamjo, Southeastern Sweden, appears promising. According to the owners, the mixed-species stands perform well financially. The management system is well defined and aims at the production of veneer-quality oak wood with Norway spruce as an economic buffer early in the rotations (Staal 1986). We decided to investigate both the biogeochemical and the economic sustainability of the mixed-species stands there as well as of the adjacent Norway spruce monocultures. Matters of biodiversity are as yet to be investigated. It is reasonable, however, to expect there to be better possibilities for maintaining a high level of biodiversity in mixed spruce/oak forest stands than in Norway spruce monocultures.
Managing Forest Ecosystems, 2002
The modelling adapted in the SUFOR programme attempts to take a large step forward. This chapter ... more The modelling adapted in the SUFOR programme attempts to take a large step forward. This chapter describes some of the biogeochemistry processes needed in the next step biogeochemical modelling taken in SUFOR. There are several models for nutrient dynamics and growth available, however, development of these have in some respects moved in old tracks for the last decade. We see several drawbacks in these older constructs with respect to operationality and several new steps are necessary, especially with respect to nitrogen and carbon cycling, but also with respect to developing models that operate on observable parameters. What is described in the following is the result of several theme groups that have been operative in the SUFOR Programme. The groups have been multidisciplinary, which was a great help for innovation.
Water, Air, & Soil Pollution: Focus, 2007
The effects of harvesting on the long-term mass balances of calcium (Ca), magnesium (Mg) and pota... more The effects of harvesting on the long-term mass balances of calcium (Ca), magnesium (Mg) and potassium (K) were evaluated on a regional level in Sweden. A new high-resolution weathering database was used together with estimates of total deposition, losses through harvest and leaching. Estimates were made for pine and spruce separately and for two harvesting intensity scenarios: stem harvesting and whole-tree harvesting. The mass balance calculations showed net losses of Ca and Mg in almost the whole country for both scenarios. The losses were smaller for pine than for spruce. The K balances were mainly positive for pine but negative for spruce. Leaching was a main factor in the mass balances, especially for Ca and Mg. Whole-tree harvesting in spruce forests led to substantially higher net losses of K and Ca than stem harvesting, according to the calculations. In the whole-tree harvesting scenario in spruce forests the estimated yearly net losses of Ca, Mg and K corresponded to at least 5%, 8% and 3% of the pools of exchangeable base cations, respectively, at 25% of the analysed sites. If losses of this magnitude continue the depletion of the pools of Ca, Mg and K may lead to very low base saturation of the soils, possibly accompanied by negative effects on soil fertility, runoff water quality, tree vitality and tree growth within a forest rotation in parts of Sweden. Avoiding whole-tree harvesting can improve the situation substantially for K, but the losses of Ca and Mg will still be significant.
The Holocene, 2009
Ten paleosols from four separate soil pits located in Kärkevagge, a glaciated trough in Swedish L... more Ten paleosols from four separate soil pits located in Kärkevagge, a glaciated trough in Swedish Lapland, were dated using radiocarbon. Each soil was dated using both conventional bulk soil organic material (SOM) and a pure sample of arbuscular mycorrhizae (AM) fungal spores. The latter are produced by ubiquitous mycorrhizal fungi associated with the roots of many plant genera and may be viewed as a fossil material that has not interacted with any soil constituent subsequent to its emplacement in the soil — at a time presumed to mark the cessation of a favorable soil-forming environment. Regional deglaciation is presumed to have been about 10 000 BP, while a cosmogenic exposure date obtained from the valley floor in Kärkevagge dated at 13 100 ± 1638 BP. The youngest paleosol, buried at ~6 cm in soil pit M3, produced a spore date of 0—281 cal. yr BP (1σ). However, bulk SOM dates of the same paleosol A horizon gave widely divergent dates and varied with the sample pretreatment, ie, the...
Systems Research and Behavioral Science, 2008
The Tyranny of Small Steps (TYST) behaviour has been investigated. Explained through a systemic p... more The Tyranny of Small Steps (TYST) behaviour has been investigated. Explained through a systemic perspective, the behaviour TYST is an unwanted change to a system through a series of small activities that may be independent from one another. These activities are small enough not to be detected by the 'surveillance' within the system, but significant enough to encroach upon the 'tolerance zone' of the system and compromise integrity of the system. TYST is an unintentional process that is experienced within the system and made possible by the lack of transparency between an overarching level and a local level where the encroachment is taking place. The Ö rby case study illustrates a real life manifestation of the TYST behaviour in management and planning. The TYST illustrates the necessity for total transparency in any systems in order to avoid unintended consequence. The TYST process may be regarded as a part of wide range of complex systems but depending on the conditions, it can remain dormant, and only become active when the conditions for lack of transparency are fulfilled.
Journal of Sustainable Forestry, 2006
We suggest a method of analyzing the sustainability conditions for forestry from three major real... more We suggest a method of analyzing the sustainability conditions for forestry from three major realms: environmental, social, and economic. The tools and methods were tested at sites in Sweden. Assessments were made for the long-term sustainability concerning the impact of present management practices on the balances of nutrients in monocultures and mixed-species stands. In the economic assessments, both traditional terms
Geoderma, 2000
Ž 14. A promising technique for dating paleosols is reported based on radiocarbon C dating of Ž. ... more Ž 14. A promising technique for dating paleosols is reported based on radiocarbon C dating of Ž. asexual spores from vesicular-arbuscular mycorrizae VAM. The soils are dispersed in water and some 6000-8000 spores separated by hand picking under a low power microscope. The dried Ž. spores are then dated by accelerator mass spectroscopy AMS. A chronosequense of closely superimposed paleosols from an arcticralpine meadow soil, northern Sweden, was dated and the Ž. long-term i.e., over a millennium time-span organic carbon loss rate determined. A very low carbon loss rate was obtained, 4.7 = 10 y4 " 9.2 = 10 y5 year y1. It is argued that this approach is likely to give a better estimate for long-term loss than litter-bag studies covering a couple of decades.
Geoderma, 2006
Information on soil mineralogy is essential for weathering rate calculations. Quantitative minera... more Information on soil mineralogy is essential for weathering rate calculations. Quantitative mineralogical analyses are expensive and time-consuming, and thus indirect methods of determining the mineralogical composition are important, for example estimating the composition based on the elemental content in till (total concentrations), or based on information about the underlying bedrock. The mineralogical composition and the elemental content in till were analysed in two areas in southern Sweden, at 10 sites in each area. There were significant differences between the areas regarding both elemental content and optically determined mineralogy. The content of calcium was significantly higher in one area, 5ESV, and there were tendencies in this direction also for magnesium and iron. The potassium content was significantly higher in the other area, 6FNV. The variation in soil chemistry between the areas can be explained by higher contents of the minerals biotite, hornblende and epidote in the first area (5ESV) and higher contents of K-feldspar in the second (6FNV). Normative mineralogy was determined based on the elemental content. A comparison between the normative mineralogy and the optically determined mineralogy showed great similarities which indicates that there is good potential for using elemental content for estimating the mineralogical composition. The difference in till composition between the areas could not be explained by the underlying bedrock, which indicates that the information available on the bedrock is not sufficient for estimation of the till mineralogical composition.
Chemical weathering is one of the most important processes supporting life on Earth. Chemical wea... more Chemical weathering is one of the most important processes supporting life on Earth. Chemical weathering continuously contributes macronutrients and micronutrients to the soil solution. These recycling, essential elements are used as building blocks for all organic living matter. ...
AMBIO: A Journal of the Human Environment, 2005
A systems analysis approach was used to assess farmscale nutrient and trace element sustainabilit... more A systems analysis approach was used to assess farmscale nutrient and trace element sustainability by combining full-scale field experiments with specific studies of nutrient release from mineral weathering and trace-element cycling. At the Ö jebyn dairy farm in northern Sweden, a farm-scale case study including phosphorus (P), potassium (K), and zinc (Zn) was run to compare organic and conventional agricultural management practices. By combining different element-balance approaches (at farmgate, barn, and field scales) and further adapting these to the FARMFLOW model, we were able to combine mass flows and pools within the subsystems and establish links between subsystems in order to make farm-scale predictions. It was found that internal element flows on the farm are large and that there are farm internal sources (Zn) and loss terms (K). The approaches developed and tested at the Ö jebyn farm are promising and considered generally adaptable to any farm.
Water, Air, & Soil Pollution: Focus, 2004
Weathering rates of base cations are crucial in critical load calculations and assessments of sus... more Weathering rates of base cations are crucial in critical load calculations and assessments of sustainable forestry. The weathering rate on a single site with detailed geological data can be modelled using the PROFILE model. For environmental assessments on a regional scale, the weathering rates for sites are scaled into regional maps. The step from sites to regional level requires focus on the spatial variation of weathering rates. In this paper, a method is presented by which weathering rates are calculated for 25589 Swedish sites with total elemental analysis for the soil. Based on a part of the results, a methodology for creating area covering maps by geostatistical analysis and kriging is described. A normative reconstruction model was used to transform total elemental analysis to mineralogy. Information from the Swedish Forest Inventory database and other databases were used to derive texture and other important information for the sites, e.g. climate, deposition and vegetation data. The calculated weathering rates show a regional pattern that indicates possibilities for interpolation of data in large parts of Sweden. Geostatistical analysis of an area in southern Sweden shows different properties for different base cations. Kriging was performed for potassium to demonstrate the method. It was concluded that different base cations and different regions have to be analysed separately, in order to optimise the kriging method.
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Papers by Johan Holmqvist