Surveying biodiversity in protected and managed areas: Algae, macrophytes and macroinvertebrates in boreal forest streams

Extensive surveys of biodiversity in protected and managed areas have not been conducted for a majority of taxonomic groups and ecosystem types, which makes it difficult to assess how large a portion of biodiversity is at least potentially under protection. The situation is the same in boreal regions, and only preliminary analyses of the biodiversity patterns of less well-known organism groups, including many freshwater taxa, within the protected area network have been conducted. We studied patterns of species richness and community composition of algae, macrophytes (bryophytes and vascular plants), and macroinvertebrates of headwater streams draining protected areas and managed forests in a boreal drainage basin in Finland. We found no significant differences in the species richness and community composition of these organism groups between the protected and managed streams. Gamma- and beta-diversity varied strongly among the protected and managed stream groups, yet this variation was contingent on the organism group and the beta-diversity measure used. In general, there was much species turnover within both protected and managed stream groups, masking any between-group differences. However, we found a number of redlisted and rare species in our surveys. Of these species, several macrophyte species occurred more frequently in the protected streams. By contrast, rare species of algae and macrophytes did not generally show such inclinations to the protected streams. We found no strong congruence in species richness or community dissimilarity between algae, macrophytes, and macroinvertebrates, suggesting that the main anthropogenic gradient in terms of forestry is not strong enough to modify stream environmental conditions and thereby shape biodiversity in the focal drainage basin. This finding also suggests that surveys of aquatic biodiversity across protected and managed landscapes should not rely too heavily on the surrogate taxon approach, but instead should consider patterns shown by multiple taxonomic groups that represent biologically and ecologically disparate organisms. Our results indeed suggest that the levels of alpha-, beta-, and gamma-diversity show differing among-taxon responses to forest management and naturalness of headwater streams.     

Metabolic syndrome in an island population of the eastern Adriatic coast of Croatia

The metabolic syndrome, an assemblage of risk factors, viz., obesity, dyslipidemia, carbohydrate intolerance, and hypertension, associated with development of cardiovascular diseases and Type 2 diabetes, has become a major public health problem in the developed countries. However, data on its prevalence in worldwide populations, particularly in non-industrialized societies is sparse. We report the prevalence of metabolic syndrome in an island population of the eastern Adriatic coast of Croatia, a distinctly homogenous population living in relative isolation with a traditional way of life style pattern. The participants consist of 381 unrelated individuals (136 males, 245 females) from the island of Hvar, age 19 and above. Hvar is among the most populated Croatian islands with a total population of 11,459 individuals according to the 1991 census. Metabolic syndrome was assessed following the National Cholesterol Education Program (NCEP) criteria, with the exception of using body mass index and waist hip ratio as the predictors of obesity. Overall age-adjusted prevalence of metabolic syndrome is 26% (32% in males and 24% in females) with body mass index, and 42% (57% in males and 36% in females) with waist hip ratio as the measures of obesity. Pairwise correlations of the age and sex-adjusted individual components show that with the exception of fasting plasma glucose, the other components of metabolic syndrome are significantly associated with each other, suggesting their co-morbidity. In spite of adherence to a relatively traditional life-style pattern together with a "Mediterranean diet" and rural habitat, the prevalence of metabolic syndrome is substantially high in the population of Hvar. It is likely that factors other than nutritional practices, that might include genetic susceptibility, could potentially be important in predisposition to metabolic syndrome.     

Temporally stable abundance–occupancy relationships and occupancy frequency patterns in stream insects

The interspecific relationship between local abundance and regional distribution, as well as the occupancy frequency distribution, are widely studied topics in macroecology. A positive abundance-occupancy relationship has been found in a majority of studies, and satellite species modes are typically dominant in occupancy frequency distributions. However, there are a number of exceptions to these "general" findings, and only a few studies have examined these patterns and their temporal variability in stream organisms. I examined both abundance-occupancy relationships and occupancy frequency distributions in stream insects in a boreal drainage system over six consecutive years. I found that the positive interspecific abundance-occupancy relationship was highly stable temporally, with coefficients of determination ranging from 0.25 to 0.47 over the years. There were no strong differences in the strength and slope of the abundance-occupancy relationship between non-predatory and predatory insect species in each year. Temporally stable abundance-occupancy relationships were paralleled by among-year patterns in both abundance and occupancy, with locally abundant and widely distributed species remaining locally abundant and widely distributed over the years, while locally uncommon and regionally rare species showed the opposite. Occupancy frequency distributions were strongly right-skewed, mirroring the dominance of the left-most satellite mode of regionally rare species. That the abundance-occupancy relationship, species' abundances and distributions, as well as the dominance of satellite species in occupancy frequency distribution were temporally stable suggest that niche-based models are strong candidates for explaining these patterns in stream insects. By contrast, metapopulation-based models that predict clear temporal variability in species' abundance and occupancy, as well as bimodal occupancy frequency distributions, are less plausible candidates for explaining the observed patterns. The present findings are the opposite to those in some terrestrial studies, but they are in agreement with other terrestrial studies and with a few previous studies on stream organisms.     

Species richness and taxonomic distinctness of lake macrophytes along environmental gradients in two continents

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HLA class II gene and haplotype diversity in the population of the island of Hvar, Croatia

The DRB1, DRB3, DRB5, DQA1 and DQB1 allele polymorphisms were analysed in 3 western and 3 eastern villages of the island of Hvar using PCR-SSOP method and 12th International Workshop primers and probes. Three DQB1 alleles (*0304, *0305, *0607) detected in the population of the island of Hvar (HP) have not yet been observed in general Croatian population (GCP). Significant differences were observed between two regions of Hvar for: a) DRB1*0701 allele (p < 0.001), b) DQA1*0201 allele (p < 0.01), and c) DRB1*0101-DQA1*0101-DQB1*0501 haplotypic association (p < 0.05). Two unusual haplotypic associations, which have not yet been described in general Croatian population (GCP), DRB1*0101-DQA1*0102-DQB1*0501 and DRB1*1501-DQA1 *0102-DQB1*0604 were observed in the population from the island of Hvar (HP). Measures of genetic kinship and genetic distances revealed isolation and clusterization which coincides with the known ethnohistorical, as well as biological and biocultural data obtained from a series of previous investigations. The five studied village subpopulations formed two clusters (East-West) to which the far eastern village (with the highest rii of 0.0407) joined later, thus indicating possible impact of historical immigrations from the mainland.     

Potential for Aerobic and Anaerobic Biodegradation of Petroleum Hydrocarbons in Boreal Subsurface

We studied the role of aerobic and anaerobic petroleum hydrocarbon degradation at a boreal, light-weight fuel and lubrication oil contaminated site undergoing natural attenuation. At the site, anoxic conditions prevailed with high concentrations of CH4 (up to 25% v/v) and CO2 (up to 18% v/v) in the soil gas throughout the year. Subsurface samples were obtained mainly from the anoxic parts of the site and they represented both the unsaturated and saturated zone. The samples were incubated in microcosms at near in situ conditions (i.e. in situ temperature 8 degrees C, aerobic and anaerobic conditions, no nutrient amendments) resulting in the removal of mineral oil (as determined by gas chromatography) aerobically as well as anaerobically. In the aerobic microcosms on average 31% and 27% of the initial mineral oil was removed during a 3- and 4-month incubation, respectively. In the anaerobic microcosms, on average 44% and 15% of the initial mineral oil was removed during a 12- and 10-month anaerobic incubation, respectively, and e.g. n-alkanes from C11 to C15 were removed. A methane production rate of up to 2.5 microg CH4 h(-1) g(-1) dwt was recorded in these microcosms. In the aerobic as well as anaerobic microcosms, typically 90% of the mineral oil degraded belonged to the mineral oil fraction that eluted from the gas chromatograph after C10 and before C15, while 10% belonged to the fraction that eluted after C15 and before C40. Our results suggest that anaerobic petroleum hydrocarbon degradation, including n-alkane degradation, under methanogenic conditions plays a significant role in the natural attenuation in boreal conditions.     

Stress- and metabolic responses of Candida albicans require Tor1 kinase N-terminal HEAT repeats

Whether to commit limited cellular resources toward growth and proliferation, or toward survival and stress responses, is an essential determination made by Target of Rapamycin Complex 1 (TORC1) for a eukaryotic cell in response to favorable or adverse conditions. Loss of TORC1 function is lethal. The TORC1 inhibitor rapamycin that targets the highly conserved Tor kinase domain kills fungal pathogens like Candida albicans, but is also severely toxic to human cells. The least conserved region of fungal and human Tor kinases are the N-terminal HEAT domains. We examined the role of the 8 most N-terminal HEAT repeats of C. albicans Tor1. We compared nutritional- and stress responses of cells that express a message for N-terminally truncated Tor1 from repressible tetO, with cells expressing wild type TOR1 from tetO or from the native promoter. Some but not all stress responses were significantly impaired by loss of Tor1 N-terminal HEAT repeats, including those to oxidative-, cell wall-, and heat stress; in contrast, plasma membrane stress and antifungal agents that disrupt plasma membrane function were tolerated by cells lacking this Tor1 region. Translation was inappropriately upregulated during oxidative stress in cells lacking N-terminal Tor1 HEAT repeats despite simultaneously elevated Gcn2 activity, while activation of the oxidative stress response MAP kinase Hog1 was weak. Conversely, these cells were unable to take advantage of favorable nutritional conditions by accelerating their growth. Consuming oxygen more slowly than cells containing wild type TOR1 alleles during growth in glucose, cells lacking N-terminal Tor1 HEAT repeats additionally were incapable of utilizing non-fermentable carbon sources. They were also hypersensitive to inhibitors of specific complexes within the respiratory electron transport chain, suggesting that inefficient ATP generation and a resulting dearth of nucleotide sugar building blocks for cell wall polysaccharides causes cell wall integrity defects in these mutants. Genome-wide expression analysis of cells lacking N-terminal HEAT repeats showed dysregulation of carbon metabolism, cell wall biosynthetic enzymes, translational machinery biosynthesis, oxidative stress responses, and hyphal- as well as white-opaque cell type-associated genes. Targeting fungal-specific Tor1 N-terminal HEAT repeats with small molecules might selectively abrogate fungal viability, especially when during infection multiple stresses are imposed by the host immune system.