Timo Helle

Foraging conditions, tooth wear and herbivore body reserves: a study of female reindeer

Abstract Several aspects of the life history of reindeer (Rangifer tarandus) are related to the nutritional condition of the animals. Moreover, compensatory growth and fattening in summer decreases with age. The interaction of tooth wear and the standing crop of lichens on age-related variation in body size and tissue reserves was examined to evaluate the proximate causes of density-dependent food limitation on life history parameters in female reindeer. Studies in nine semi-domesticated free-ranging reindeer herds showed that molar height depended on the mean standing crop of terrestrial lichens in winter habitats. The extent of tooth wear had the strongest effect on body reserves among the oldest females (11–14 years). This indicates that severe tooth wear limits the animals´ ability to process food efficiently and, hence, to maintain their body reserves. Both tooth wear and the biomass of lichens influenced body mass in old females, probably because on heavily exploited winter ranges reindeer had to use higher proportions of lower-ranking coarser foods, especially dwarf shrubs.

The effects of outdoor recreation on range use by semi‐domesticated reindeer

The effects of a large holiday resort on the distribution and range use of semi‐domesticated reindeer were studied in the three most important habitat types in Saariselka, eastern Finnish Lapland. In two of these habitats the relative reindeer densities increased in winter, when outdoor activities declined reaching density equal to the average for the herding association at a distance of about 10 km from the holiday resort. In summer, male reindeer adapted better than females to the proximity of the holiday resort. The feeding site preferences of the reindeer during winter followed, in general, the normal pattern in areas with little human interference. Although the economic value of the range loss appeared small compared to the gain from outdoor enterprises, better planning is needed to avoid the harmful effects of recreation on reindeer management.

Effects of lichen biomass on winter diet, body mass and reproduction of semi-domesticated reindeer Rangifer t. tarandus in Finland

Winter food supply very likely influences the life history of reindeer Rangifer t. tarandus. We therefore examined how lichen biomass affects winter diet composition, body mass and reproduction in 14 herds of semi-domesticated reindeer in northern Finland. Diet composition was assessed microhistologically on faeces collected from the actual winter feeding sites of reindeer. When lichen was scarce at these sites reindeer included vascular plants and mosses in their diet. Calf dressed weight depended on both ground lichen biomass and the intensity of supplemental feeding, doe dressed weight depended on lichen biomass alone. One explanation for this difference between calves and does is the connection between food supply and calf mortality: low lichen biomass may promote newborn mortality, which, in turn, frees breeding females from investing further in current reproductive investment. Relative offspring weight (calf/female weight ratio) depended on both lichen biomass and supplemental feeding. Low lichen availability appeared to enhance the impact of density-independent factors on reproduction, because the annual variation in reproductive rate increased with decreasing lichen biomass.

Direct and correlative phenotypic selection on life-history traits in three pre-industrial human populations

Because natural selection acts simultaneously on several correlated traits, a single trait can be under both direct and correlative selection simultaneously. Correlative selection may either weaken or magnify the association between a trait and fitness. Direct effect of a single trait on fitness can be assessed by removing the effects of correlative selection with multivariate techniques. We studied the phenotypic selection on demographic life-history traits in three pre-industrial human populations, which experienced different mortality environments. We used path-analysis to estimate direct and correlative selection on different traits in females and males. Our results indicate substantial differences among the sexes in the force of phenotypic selection on key life-history traits. For females, the most important component of reproductive success was the age at first reproduction. Most important component of fitness for males was the quality of mate. In addition, our analysis revealed considerable among-population variation in the selection on life-history traits. These differences are in accord with the historical notes of among-population variation in the lifestyle and harshness of the environment, suggesting that among-population variation in life-history traits may have been a response to the environmental variation.

Use of decision analysis interviews to support the sustainable use of the forests in Finnish Upper Lapland

Controversy between alternative uses of forests in Finnish Upper Lapland has been going on for decades, and in recent years it has been escalated to a serious conflict. The core of the conflict is the adverse impacts of forestry on old forests which are important grazing areas for reindeer and which are regarded as intact nature and wilderness areas. This paper describes the experiences of applying multi-criteria decision analysis interview approach on this conflict. The approach provides tools for structuring the problem and preferences of the stakeholders as well as for analyzing the effects of different alternatives in a common framework. We focus on the practical experiences gained from the application of this approach in this context. Multi-criteria decision analysis was found to be a useful approach to evaluate the economic, ecological and cultural aspects of this intense conflict. The obtained experiences also support the view that the approach works best when tightly integrated into the planning process.

Trichloroacetic acid in conifer needles and arboreal lichens in forest environments

In the past, trichloroacetic acid (TCA) was a commonly used herbicide, which caused alterations in the properties of surface wax, inhibited growth and caused leaf necrosis. TCA is also a degradation product of short chain chlorocarbons which are used as solvents and degreasers in industry. TCA may also originate from the bleaching of kraft pulp with agents containing chlorine. In this study TCA concentrations in conifer needles were determined in several rural forest areas in subarctic regions in Finland. TCA was analyzed as its methyl ester by GCNCI-MSSIR. The TCA levels in the third-year needles varied in the range 1–180 μg kg−1 (median 23 μg kg−1, n = 130); 90% of the values being between 5 and 70 μg kg−1. No regional concentration trends could be observed. TCA was also present in arboreal lichens of conifers, which is further proof of its atmospheric origin. Comparison of the TCA levels in Usneaceae lichens with lichen biomass gave a significant negative correlation (P = 0.02), whereas TCA concentrations in needles and visible symptoms of tree vitality did not show causal relationships.

Sexual Conf lict and Remarriage in Preindustrial Human Populations: Causes and Fitness Consequences

Sexual conflict is said to occur when one mating partner has an opportunity to increase its fitness at the cost of the other. We analyzed the effect of remarriage on lifetime reproductive success (LRS) in three preindustrial (1700–1900) socially monogamous Sami populations. In all populations, ever-married women’s age-specific mortality rates exceeded those of ever-married men during reproductive years. After the death of a spouse, men had a higher probability of remarriage than did women of the same age. Remarried men had a higher LRS than men who married only once, but this was not true for women. The higher LRS of the twice-married men was probably due to their longer (+5 years; p < .05) reproductive lifespan (RLS) as compared to once-married men. There was no difference in the RLS of women who married once or twice. These results suggest the sexual conflict in these populations was won by men because women paid a higher cost from reproduction (i.e., reduced survival), and men were able to remarry more often than women, thereby realizing more of their higher reproductive potential. Consequently, serial monogamy seem to have been an important male reproductive strategy in these historical populations.

Capercaillie (Tetrao urogallus) Lekking sites in fragmented Finnish forest landscape

The location of Capercaillie lekking sites was compared in forest mosaics of different level of fragmentation. In north Finland the stand characteristics of the lekking sites did not differ from those of randomly selected stands in the 1950s judged from forestry maps and stand registers. In the 1980s, when forestry had considerably altered stand structure, lekking stands were older, larger and had a higher timber volume than random stands. These features evenly changed from the lek centre to the distance of 4 km, to which distance the adjacent areas were assessed. Southern and central Finnish analyses, based on topographic maps, showed that the proportion of forest distinctly decreased with increasing distance from a lek centre, up to a distance of 1–1.5 km. The average patch size of lekking stands were largest in the north (where both cut areas and remaining stands are large) and smallest in central Finland dominated by fine‐grained forest landscape. The results are discussed in terms of landscape ecolog...

Lichen ranges, animal densities and production in Finnish reindeer management

In the 1970s, mean lichen biomass ranged by the earmark districts (comprising of 2-9 adjacent herding associations) between 54 kg and 380 kg DM per ha correlating negatively with animal density per lichen ranges (range 1.5 - 14.3 ind. per km2). Biomasses were far below economic carrying capacity of lichen ranges (900 kg DM per ha). The condition of lichen ranges was poorest in the southern half of the area where alternative food to reindeer lichens (Deschampsia flexuosa, arboreal lichens and supplementary feeding) was available. In 1980-86, recruitment (calves per 100 females) was 33% higher than in the 1970s, on an average (65 vs. 49), despite a 90% increase in animal numbers between 1970 and 1986; recruitment has not been dependent on the condition of lichen ranges. The increase in production has been some higher than expected on the basis of animal numbers. The reasons for the increasing trends in animal numbers, recruitment and production remains some unclear, but they may include favorable winter conditions, supplementary feeding, medical treatment against parasites and proper harvesting policy.

Erratum to: Both reindeer management and several other land use factors explain the reduction in ground lichens (Cladonia spp.) in pastures grazed by semi-domesticated reindeer in Finland

Roles of intensive reindeer grazing and several additional land use factors in the reduction in ground lichens (Cladonia spp.) in pastures grazed by the semi-domesticated reindeer have been argued in Finland. Our analysis showed that several factors and processes explain the standing biomass of lichens (during 2005–2008) and the recent changes in this biomass (after 1995–1996) on lichen pastures located in the 20 northernmost herding districts in Finland. The higher the long-term reindeer densities on the lichen pastures the lower was the lichen biomass. The lichen biomass was also strongly affected by the grazing system; the lowest biomass values of lichens were measured in all grazing areas that were used in the snow-free seasons. The lichen biomass in pine forests less than 80 years old and in all mountain type lichen pastures was lower than that in mature and old pine forests. The lichen biomass also decreased as the proportion of arboreal lichen pastures within a district decreased and the proportion of human infrastructure increased. The aerial drift of heavy metals from the Kola Peninsula appeared to reduce lichens in a small north-eastern part of the study area. Increases in summer precipitation and winter temperatures increased the amount of lichens, but increases in summer temperatures and winter precipitation had the opposite effect. Reindeer densities, grazing system, pasture type and the previous abiotic factors were also associated with the reduction in lichen biomass between the inventories. We conclude that several local, regional and even global factors and processes affect the state of reindeer pastures in large and complex grazing ecosystems. Therefore, more comprehensive research and management strategies for the entire reindeer herding environment are needed.