Mattias Carlsson

Costs of Alien Invasive Species in Sweden

Abstract The purpose of this paper is to present calculations of total costs of 13 alien invasive species (AIS) in Sweden. All species are subject to control by Swedish public authorities, and estimates for most AIS include either damage cost or actual control cost. The results indicate a total annual cost between approximately 1620 and 5080 million SEK, which correspond to SEK 175 and SEK 565 per capita in Sweden. The estimates are well within the range of similar calculations for other countries, but differ with respect to the composition of costs of different AIS. Whereas costs for the agricultural and forestry sectors dominate in most other studies, the costs of AIS in Sweden are more equally divided among different categories. The results also indicate that the highest costs are attributable to unintentionally introduced AIS and that the most reliable cost estimates are related to human and animal health.

Nature conservation and timber production in areas with fragmented ownership patterns

Abstract Forestry has transformed the tree species composition and structure of Swedish forests. The fragmented ownership pattern in areas with non-industrial private forest ownership (NIPF), in combination with these forestry practices, have created fragmented forests with relatively low proportions of habitat types important to many species. Ecological landscape planning has been suggested and tested as a mean for integrating nature conservation and timber production in Sweden. However, ecological landscape planning concepts have been developed for areas with homogenous ownership patterns and not for areas with fragmented ownership. In this study, stands that are voluntarily set aside by individual forest owners were examined in terms of nature conservation value, and compared to randomly selected stands obtained by Monte Carlo simulation. In order to obtain rather detailed data about the set-aside stands, semi-standardized interviews were carried out directly with forest owners in three landscape areas dominated by NIPF. The interviews showed that 26 out of 29 forest owners could locate some stands where they did not have high requirements for timber yield. These stands had higher than average local and spatial nature conservation value as a result of stand structure, composition and location in the landscape. The stands did not have a random location or size, being found closer to key habitats as well as forming equally large or larger patches than other stands. These stands are suggested to form a basis for ecological landscape planning as forest owners seem to have some kind of ‘common view’ of which stands to set aside. This common view could be used to coordinate the contribution made by individual forest owners to nature conservation in areas with fragmented ownership patterns.

Spatial patterns of habitat protection in areas with non-industrial private forestry—hypotheses and implications

Selection of certain habitat types on landscape, regional or national scales in order to conserve or create desirable ecological structures and/or compositions are often part of nature conservation strategies. In state-owned and industry-owned forests, selection of habitats for nature conservation purposes has been a question of maximizing ecological benefits. In non-industrial private forestry (NIPF), the choice of habitat type affects to what area fraction habitats occur on a forest estate. As this can vary considerably between forest estates, decision makers should consider this variation (the variation in habitat occurrence) when selecting habitat type for habitat protection programs. In this paper, a hypothesis based on the abundance, the average size, and average shape of habitats was developed to explain distribution of habitat occurrence. Monte Carlo simulations and empirical studies of 11,700 ha and 194 forest estates showed that variation in habitat occurrence can be analyzed with information of abundance, size and shape of a specific habitat type.

A Ham1p-Dependent Mechanism and Modulation of the Pyrimidine Biosynthetic Pathway Can Both Confer Resistance to 5-Fluorouracil in Yeast

5-Fluorouracil (5-FU) is an anticancer drug and pyrimidine analogue. A problem in 5-FU therapy is acquired resistance to the drug. To find out more about the mechanisms of resistance, we screened a plasmid library in yeast for genes that confer 5-FU resistance when overexpressed. We cloned five genes: CPA1, CPA2, HMS1, HAM1 and YJL055W. CPA1 and CPA2 encode a carbamoyl phosphate synthase involved in arginine biosynthesis and HMS1 a helix-loop-helix transcription factor. Our results suggest that CPA1, CPA2, and HMS1 confer 5-FU resistance by stimulating pyrimidine biosynthesis. Thus, they are unable to confer 5-FU resistance in a ura2 mutant, and inhibit the uptake and incorporation into RNA of both uracil and 5-FU. In contrast, HAM1 and YJL055W confer 5-FU resistance in a ura2 mutant, and selectively inhibit incorporation into RNA of 5-FU but not uracil. HAM1 is the strongest resistance gene, but it partially depends on YJL055W for its function. This suggests that HAM1 and YJL055W function together in mediating resistance to 5-FU. Ham1p encodes an inosine triphosphate pyrophosphatase that has been implicated in resistance to purine analogues. Our results suggest that Ham1p could have a broader specificity that includes 5-FUTP and other pyrimidine analogoue triphosphates.

Gene dosage effects in yeast support broader roles for the LOG1, HAM1 and DUT1 genes in detoxification of nucleotide analogues

Purine and pyrimidine analogues have important uses in chemotherapies against cancer, and a better understanding of the mechanisms that cause resistance to these drugs is therefore of importance in cancer treatment. In the yeast Saccharomyces cerevisiae, overexpression of the HAM1 gene encoding inosine triphosphate pyrophosphatase confers resistance to both the purine analogue 6-N-hydroxylaminopurine (HAP) and the pyrimidine analogue 5-fluorouracil (5-FU) (Carlsson et al., 2013, PLoS One 8, e52094). To find out more about the mechanisms of resistance to nucleotide analogues, and possible interdependencies between purine and pyrimidine analogue resistance mechanisms, we screened a plasmid library in yeast for genes that confer HAP resistance when overexpressed. We cloned four such genes: ADE4, DUT1, APT2, and ATR1. We further looked for genetic interactions between these genes and genes previously found to confer resistance to 5-FU. We found that HMS1, LOG1 (YJL055W), HAM1, and ATR1 confer resistance to both 5-FU and HAP, whereas ADE4, DUT1 and APT2 are specific for HAP resistance, and CPA1 and CPA2 specific for 5-FU resistance. Possible mechanisms for 5-FU and HAP detoxification are discussed based on the observed genetic interactions. Based on the effect of LOG1 against both 5-FU and HAP toxicity, we propose that the original function of the LOG (LONELY GUY) family of proteins likely was to degrade non-canonical nucleotides, and that their role in cytokinin production is a later development in some organisms.

The histone demethylase activity of Rph1 is not essential for its role in the transcriptional response to nutrient signaling.

Rph1 and Gis1 are two related yeast zinc finger proteins that function as downstream effectors in the Ras/PKA, TOR and Sch9 nutrient signaling pathways. Both proteins also contain JmjC histone demethylase domains, but only Rph1 is known to be an active enzyme, demethylating lysine 36 of histone H3. We have studied to what extent the demethylase activity of Rph1 contributes to its role in nutrient signaling by performing gene expression microarray experiments on a yeast strain containing a catalytically inactive allele of RPH1. We find that the enzymatic activity of Rph1 is not essential for its role in growth phase dependent gene regulation. However, the ability of Rph1 to both activate and repress transcription is partially impaired in the active site mutant, indicating that the demethylase activity may enhance its function in vivo. Consistent with this, we find that the Rph1 mutation and a deletion of the histone H3 methylase Set2 affect the same target genes in opposite directions. Genes that are differentially expressed in the Rph1 mutant are also enriched for binding of Rpd3, a downstream effector in silencing, to their promoters. The expression of some subtelomeric genes and genes involved in sporulation and meiosis are also affected by the mutation, suggesting a role for Rph1-dependent demethylation in regulating these genes. A small set of genes are more strongly affected by the active site mutation, indicating a more pronounced role for the demethylase activity in their regulation by Rph1.

Models of the risk of windthrow and frost

Several hazards for forest production can be identified, such as damage caused by wind, frost, insects or pathogens. Modelling efforts of ours have been concentrated upon the risks of damages by wind and frost, landscape level models for which will be presented below. A landscape is defined as an area of anywhere from a few km2 to several tens of km2.