Coarse woody debris in late-successional Picea abies forests in northern Europe: Variability in quantities and models of decay class dynamics

Coarse woody debris pools and their decay class dynamics were studied in three areas of unmanaged boreal forest in northern Finland, and in the Murmansk and Arkhangelsk provinces in northwestern Russia. The study areas had varying climatic and edaphic conditions, and disturbance histories. Living and dead trees (diameter at 1.3 m height ≥10 cm) were measured in five late-successional Picea abies-dominated stands in each of the three areas. Wood density and time since death were determined from randomly sampled dead P. abies, and their decay class dynamics were modeled using stage-based matrix models.     

Five plant families support natural sporulation of <Emphasis Type="Italic">Cronartium ribicola</Emphasis> and <Emphasis Type="Italic">C. flaccidum</Emphasis> in Finland

Fusarium is one of the most destructive fungal genera whose members cause many diseases on plants, animals, and humans. Moreover, many Fusarium species secrete mycotoxins (e.g. trichothecenes and fumonisins) that are toxic to humans and animals. Fusarium isolates from date palm trees showing disease symptoms, e.g. chlorosis, necrosis and whitening, were collected from seven regions across Saudi Arabia. After single-sporing, the fungal strains were morphologically characterized. To confirm the identity of morphologically characterized Fusarium strains, three nuclear loci, two partial genes of translation elongation factor 1 α (tef1α) and β-tubulin (tub2), and the rDNA-ITS region, were amplified and sequenced. Of the 70 Fusarium strains, 70 % were identified as F. proliferatum that were recovered from six regions across Saudi Arabia. Fusarium solani (13 %), as well as one strain each of the following species: F. brachygibbosum, F. oxysporum, and F. verticillioides were also recovered. In addition, five Fusarium-like strains were recognized as Sarocladium kiliense by DNA-based data. The preliminary in vitro pathogenicity results showed that F. proliferatum had the highest colonization abilities on date palm leaflets, followed by F. solani. Although F. oxysporum f. sp. albedinis is the most serious date palm pathogen, F. proliferatum and F. solani are becoming serious pathogens and efforts should be made to restrict and control them. In addition, the potential toxin risks of strains belonging to F. proliferatum should be evaluated.     

Do different agronomic soil tests identify similar nutrient deficiencies?

Traditionally, locally calibrated soil tests were used for fertilizer and lime recommendations. Farmers and advisors are increasingly using new ‘universal’ soil tests without local calibration. The objective of this study was to compare five commercially available soil tests and to determine whether they would provide similar recommendations. In total, 24 fields in Western Finland were sampled for 4 years while being treated with fertilizers, lime and manure. The soil samples were analysed with Mehlich-3, ammonium acetate, H3A, hydrochloric acid and mild acetic acid (Spurway) extractants. In addition, Soil Health Tool (CO₂ burst, water-soluble C and N) and tissue testing were conducted. The different tests extracted different orders of magnitude of nutrients (especially P and Mg), but the results from the different extractions were correlated. Mehlich-3 degree of phosphorus saturation (DPS) presented a threshold, below which soluble phosphorus was not detected. Similar thresholds were found for P, S and Mg. Mehlich-3 and ammonium acetate provided similar results for Ca, Mg and K and can be used interchangeably for liming recommendations. Mehlich-3 identified more fields with Zn, Cu, B and S deficiencies and less fields with Mn deficiencies compared with ammonium acetate + EDTA and tissue testing. The tests had strong correlation, but the determination of nutrient deficiencies needs local calibration of deficiency limits.     

Do carbon farming practices build bioavailable nitrogen pools?

Agricultural soils contain large amounts of nitrogen (N), but only a small fraction is readily available to plants. Despite several methods developed to estimate the bioavailability of N, there is no consensus on which extraction methods to use, and which N pools are critically important. In this study, we measured six soil N pools from 20 farms, which were part of a multi-year soil carbon sequestration on-farm experiment (Carbon action, 2019–2023). The aim was to quantify the N pools and to evaluate if farming practices that aim to build soil carbon pools, also build bioavailable N pools. We also aimed to test if the smaller and rapidly changing N pools could serve as an indicator for the slower change in soil organic matter. The measured N pools decreased in size, when moving from total N (7700 ± 1500 kg/ha) to slowly cycling (Illinois Soil Nitrogen Test ISNT-N: 1063 ± 220 kg/ha, autoclave citrate-extracted ACE protein N: 633 ± 440 kg/ha), water-soluble organic N (50 ± 17 kg/ha), potentially mineralizable N (33 ± 13 kg/ha) and finally readily plant available inorganic pools (nitrate and ammonium, total: 14 ± 8 kg/ha). In total, the measured pools covered only 18%–44% of total N, indicating a large unidentified N pool, which is either tightly bound to soil mineral fraction and not easily extractable or is bound to undecomposed plant residues and not hydrolysed by the methods. Of the large N pools (ISNT-N, ACE protein and unidentified residual N), clay, carbon (C) and C:Clay ratios explained most of the variability (R² = .90–.93), leaving a minor part of the variation to the management effect. A pairwise comparison of carbon farming and control plots concluded that farming practices had a small (3%–5%) but statistically significant (p < .05) effect on soil total N and ISNT-N pools, and a moderate and significant effect (18%, p < .01) on potentially mineralizable N. The large variation in protein N, water-soluble organic N and inorganic N reduced statistical significance, although individual C sequestration practices had large effects (−30% to +50%). In conclusion, carbon sequestration practices can build both slowly cycling N pools (ISNT) and increase the mineralisation rate of these pools to release plant available forms, resulting in an additional benefit to agriculture through reduced fertilizer application needs.     

Extreme neutral genetic and morphological divergence supports classification of Adriatic three-spined stickleback (Gasterosteus aculeatus) populations as distinct conservation units

The fact that the intraspecific genetic differentiation in neutral genetic markers and genes coding for adaptive traits are not typically correlated has caused a great deal of conceptual and practical trouble in delimitation of conservation units. Although the importance of combining information on adaptive genetic divergence with information on historical and recent gene flow in the delimitation of conservation units has been recognized, integrated empirical studies to this end are still rare. We explored the evidence for the specific conservation status of two freshwater three-spined stickleback (Gasterosteus aculeatus) populations on the Adriatic side of the Balkan Peninsula by comparing their phenotypic and genetic characteristics to those of other representative European populations. Apart from focusing on the neutral genetic divergence in mitochondrial DNA sequences and microsatellite markers, we also compared the patterns of morphological differentiation (i.e. bony armour development) resulting from adaptation to freshwater environments. The Balkanic populations formed two distinct groups with regard to neutral genetic variation and had the least developed bony armour of all the examined populations. All morphometric analyses identified the two Balkanic populations as phenotypically – and hence most likely also ecologically – clearly distinct from other European three-spined stickleback populations. These results suggest that the two Balkanic populations (River Neretva and River Zeta) fulfil the most stringent criteria (i.e. lack of genetic and ecological exchangeability) to be classified as conservation units distinct from other European three-spined stickleback populations.     

Weak effects of farming practices corresponding to agricultural greening measures on farmland bird diversity in boreal landscapes

Context

The current Common Agricultural Policy (CAP) of the European Union includes three greening measures, which are partly intended to benefit farmland biodiversity. However, the relative biodiversity effects of the greening measures, including joint effects of landscape context, are not well understood.

Objectives

We studied the effects of increasing crop diversity, proportions of production grasslands and fallows, corresponding to CAP greening measures, on open farmland bird diversity, whilst controlling for the effects of distance to forests, field edge density and proportion of built-up areas.

Methods

We surveyed open farmland birds using territory mapping in Southern Finland. We modelled effects of greening measures and landscape structure on farmland birds (7642 territories) using generalised linear mixed models.

Results

Increasing proportions of grasslands increased farmland bird species richness and diversity in open farmland, whereas increasing proportions of fallows increased bird diversity. Increasing crop diversity benefited individual species, but not species richness or diversity. Increasing field edge densities consistently increased the species richness of all farmland species, in-field nesters and non-crop nesters, as well as total farmland bird diversity. The relative effect of edge density was much stronger compared to the three greening measures.

Conclusions

Our results show that promoting fallows and grasslands, in particular grazed grasslands and various types of semi-natural grasslands, has the highest potential to benefit farmland bird diversity. Maintaining or increasing field edge densities, currently not supported, seems to be of even more benefit. In open farmland, with little or no field edges, fallows and grasslands are particularly beneficial.

     

Forest future s by Swedish students – developing a mind mapping method for data collection

Forests are an important natural resource in Sweden. They are used for multiple purposes, for example, providing economic returns from timber harvest, conservation of biodiversity, provision of wild berries and mushrooms and recreational benefits. People’s perceptions of forests and forest use are currently under transformation due to drivers like globalization and urbanization. The aim of this study was to analyse in particular Swedish university student’s visions of future forests using a newly developed survey method based on mind mapping. An online survey with mind map technique was used to collect data from university students in Umeå, northern Sweden. The study focused on features of forests, products derived from forests and activities in forests. The results indicate that students regard ecological, social and economic aspects of forests as important for future forests and the use of them. In particular, the role of non-wood forest products, like berries and mushrooms, as well as recreational features of forests were central to many of the students. The multitude of different visions suggests that forest management decisions of today, directing the future of forests, need to consider the multiple use of forests to be able to satisfy forest preferences also of younger generations.     

Changes in Collembola richness and diversity along a gradient of land-use intensity: A pan European study

Changes in Collembola richness and diversity along a land-use intensity gradient were studied in eight European countries (Portugal, Spain, France, Switzerland, Hungary, UK, Ireland and Finland). In each country a set of six 1 km² land-use units (LUUs) were selected forming a gradient ranging from natural forest to agricultural dominated landscapes, passing through mixed-use ones. In addition to data on Collembola, detailed information regarding landscape diversity and structure was collected for each LUU. A total of 47,774 individuals were identified from 281 species. Collembola reacted not only to changes in the diversity of the landscape, but also to the composition of that diversity and the area occupied by each land-use type at each LUU. Although species richness patterns were not concordant among the different countries, the total number of species per LUU (landscape richness) was generally higher in natural forests and mixed-used landscapes, and lower in agricultural dominated landscapes. Moreover, high richness and diversity of Collembola at each LUU were associated with a diverse landscape structure, both in terms of number of patches and patch richness. Despite this comparable species richness between mixed-use landscapes and those dominated by natural forests, average species richness on forested areas (local richness) decreased along the gradient, showing that forest patches on mixed-use landscapes support a lower richness than in landscapes dominated by forest. This aspect is important when addressing the role of native forests in structuring biodiversity in disturbed and fragmented landscapes. Although a diverse landscape can support a high biodiversity, the results suggest that intensive fragmentation should be avoided with the risk of collapsing local species richness with the consequent result for regional biodiversity.     

Improving broad specificity hapten recognition with protein engineering

Sulfa antibiotics (sulfonamides) are derivatives of p-aminobenzenesulfonamide that are widely used in veterinary medicine. Foods derived from treated animals may be contaminated with these drugs. However, current immunobased sulfonamide detection methods are unfit for screening of products because they are either too insensitive or specific for a few compounds only. An immunoassay capable of detecting all sulfas in a single reaction would be ideal for screening. For development of a binder capable of binding all sulfas, a protein engineering approach was chosen and the properties of monoclonal antibody 27G3 were improved with mutagenesis followed by selection with phage display. Several different mutant antibodies were isolated. The cross-reaction profile of the best mutant antibody was significantly improved over that of the wild-type antibody: it was capable of binding 9 of the tested 13 sulfonamides within a narrow concentration range and also bound the rest of the sulfas, albeit within a wider concentration range.     

Wet deposition trends of major inorganic ions in Finland based on daily bulk deposition samples

Trends in the precipitation-weighted average concentrations and in the deposition of inorganic ions in daily precipitation samples at three Finnish background stations were calculated for a period extending from the seventies to 1988. During the period 1973–1988, S0₄ ^2? concentrations in wet deposition at the station in Central Finland decreased by 39% in accordance with the emission decrease of SO₁ in Finland of 50% over the same period, and the 20% decrease in Europe from 1980 to 1988. However, due to the more significant decrease in alkaline ions (80% for Mg²⁺), H⁺ concentrations increased by 30%. At the two southernmost stations, overall concentrations are higher and the decrease of Mg²⁺ and Ca²⁺ is less important, but at the station in southeastern Finland the increase of N0₃ ^? relative to NH₄ ⁺ has doubled H⁺ concentrations during the period 1977–1988. Division of the data according to wind direction sectors showed generally decreasing concentrations in the sectors related to Scandinavia, but unchanging or increasing concentrations in the sectors related to eastern Europe. Acid deposition trends were estimated as H⁺, S0₄ ^2? - (Ca²⁺ + Mg²⁺), and H⁺ + NH₄ ⁺ - N0₃ ⁺. All these trends showed increasing acid deposition in central Finland and decreasing trends in western Finland. In eastern Finland the trends were opposing due to the increasing N0^{3 +} but decreasing NH₄ ^? trends. It is concluded that S0₄ ^2? deposition trends do not reflect acid deposition trends, and SO₄ ^2? or N0₃ ^? deposition do not geographically represent acid deposition.