Vaaka punnitsee, arvottaa, tasapainottaa -toimintamalli Vaara-Kainuun matkailualueiden suunnitteluun

Sosioekologisia työkaluja Vaara-Kainuun matkailualueiden suunnitteluun.

Temporal cycles and spatial asynchrony in the reproduction and growth of a rare nectarless orchid, Cypripedium calceolus

The timing and intensity of plant reproduction vary due to internal and external factors. Although this variation has been widely studied in species exhibiting masting (intermittent synchronous reproduction), it has attracted less attention in nonmasting species. Here, we studied intra-individual variation in the flowering intensity and plant size of a nonmasting, rare terrestrial orchid, Cypripedium calceolus, using long-term monitoring data from three populations in Finland and two populations in Estonia. Flowering intensity and plant size showed 2-year cycles, indicating that reproduction and growth were regulated by past costs of reproduction and extensive clonal growth. In addition, flowering intensity and plant size were positively correlated with size from the previous year and were also affected by the weather conditions of spring and of the previous growing season. However, there was little synchrony among plants, suggesting that the climatic control of reproduction and growth is sufficiently low as to be masked by high annual variation in these two vital rates. Together, these results indicate that the reproduction and growth of C. calceolus depend on individual demographic history and past weather conditions and that intrinsic factors can also lead to cyclic fluctuation in reproduction in nonmasting species

Phylogeography and post-glacial dynamics in the clonal-sexual orchid Cypripedium calceolus L.

Aim We investigated the phylogeographical history of a clonal-sexual orchid, to test the hypothesis that current patterns of genetic diversity and differentiation retain the traces of climatic fluctuations and of the species reproductive system. Location Europe, Siberia and Russian Far East. Taxon Cypripedium calceolus L. (Orchidaceae). Methods Samples (>900, from 56 locations) were genotyped at 11 nuclear microsatellite loci and plastid sequences were obtained for a subset of them. Analysis of genetic structure and approximate Bayesian computations were performed. Species distribution modelling was used to explore the effects of past climatic fluctuations on the species range. Results Analysis of genetic diversity reveals high heterozygosity and allele diversity, with no geographical trend. Three genetic clusters are identified with extant gene pools derived from ancestral demes in glacial refugia. Siberian populations exhibit different plastid haplotypes, supporting an early divergence for the Asian gene pool. Demographic results based on genetic data are compatible with an admixture event explaining differentiation in Estonia and Romania and they are consistent with past climatic dynamics inferred through species distribution modelling. Current population differentiation does not follow isolation by distance model and is compatible with a model of isolation by colonization. Main conclusions The genetic differentiation observed today in C. calceolus preserves the signature of climatic fluctuations in the historical distribution range of the species. Our findings support the central role of clonal reproduction in the reducing loss of diversity through genetic drift. The dynamics of the clonal-sexual reproduction are responsible for the persistence of ancestral variation and stability during glacial periods and post-glacial expansion.Peer reviewe

Adaptation, population viability and colonization-extinction dynamics of <em>Silene tatarica</em> in riparian habitats

Abstract Plants in riparian environments have to tolerate disturbances like floods and erosion. In the absence of disturbances, habitats will gradually become unfavorable for early-successional species. This can have fundamental consequences not only for adaptation at the individual level, but also for the viability of local populations as well as for the persistence of the species on a regional scale. Silene tatarica is a rare perennial plant exposed to annual floods of the Oulanka River. After sand burial most plants formed vertical rhizomes and new meristems by bud ramification. The special anatomical features of these fleshy underground structures seemed to allow the plants to be very resilient against fast-flowing water. Seed structure may enhance long-distance dispersal by water. Selection gradients for plant height were positive at the individual and group levels, but for the number of stems they were in opposition, as selection at the group level favored a smaller number of stems. This can be associated with pollination and herbivory, since taller and larger plants often attract more pollinators and mammalian herbivores. At the local level, population growth was most sensitive to the survival and growth of juvenile individuals. The populations showed different fates, and according to stochastic simulations some of them will disappear in the near future. Their colonization and extinction rates varied between the years, but their balance over the study period was positive. Small patches had the highest risk of extinction and recolonization of extinct patches was very rare. Elasticity analysis indicated that the survival of patches made a much greater contribution to patch dynamics than did the production of new patches. The short-term dynamics of S. tatarica depend primarily on local dynamics but, in the long run, the species will track the availability of habitat, and its persistence will depend on successful colonizations. The amount of suitable habitat depends on river disturbance. Conservation of this species requires the creation of new suitable open sites for colonization, a dispersal process leading to successful colonizations, and favorable habitats for survival. These conditions can be maintained either by natural processes of river disturbance or by active conservation management

Pollinator Behaviour on a Food-Deceptive Orchid Calypso bulbosa and Coflowering Species

Food deception as a pollination strategy has inspired many studies over the last few decades. Pollinator deception has evolved in many orchids possibly to enhance outcrossing. Food-deceptive orchids usually have low pollinator visitation rates as compared to rewarding species. They may benefit in visitations from the presence (magnet-species hypothesis) or, alternatively, absence of coflowering rewarding species (competition hypothesis). We present data on pollinator visitations on a deceptive, terrestrial orchid Calypso bulbosa, a species with a single flower per plant and whose flowering period partly overlaps with rewarding, early flowering willows (Salix sp.) and later-flowering bilberry (Vaccinium myrtillus). When surveying inactive bumblebee queens on willows in cool weather, about 7% of them carried Calypso pollinia. Most common bumblebee species appeared to visit and thus pollinate Calypso. Bumblebees typically visited one to three Calypso flowers before flying away, providing some support for the outcrossing hypothesis. We conclude that, regarding the pollinations strategy, both magnet-species and competition hypotheses have a role in the pollination of Calypso, but on different spatial scales. On a large scale rewarding species are important for attracting pollinators to a given region, but on a small scale absence of competition ensures sufficient pollination rate for the deceptive orchid

Pollen limitation and fruiting failure related to canopy closure in Calypso bulbosa (Orchidaceae), a northern food-deceptive orchid with a single flower

5Natural fruit set is constrained by pollen limitation and fruiting failure, and pollen limitation is expected to be especially severe in deceptive orchids. We performed hand cross-pollinations in ten populations of a food-deceptive orchid, Calypso bulbosa, under sparse and dense canopies in three non-consecutive years. We explored the relationships between natural fruit set, pollen limitation and fruiting failure. Mean natural fruit set over the years was 60%, which is exceptionally high for a deceptive orchid. On average, hand cross-pollination increased fruit set by 23%. Among open-pollinated plants that did not set a fruit, 55.5% were estimated to be pollen limited and 44.5% to be limited by fruiting failure, i.e. inability to set a fruit after pollination. In species with high natural fruit set, hand cross-pollination experiments may not always detect statistically significant pollen limitation. In our case, pollen limitation tended to become significant when the natural fruit set dropped below 60%. Canopy cover had a significant effect on fruiting failure, which was more severe under a dense canopy. Although our results demonstrate pollen limitation in many cases, they also highlight the fact that food deception can be a very effective pollination strategy.nonenoneAbeli, Thomas; Jäkäläniemi, Anne; Wannas, Lauri; Mutikainen, Pia; Tuomi, Juh

A method for assessing ecological values to reconcile multiple land use needs

We present a new method for ecologically sustainable land use planning within multiple land use schemes. Our aims were (1) to develop a method that can be used to locate important areas based on their ecological values; (2) to evaluate the quality, quantity, availability, and usability of existing ecological data sets; and (3) to demonstrate the use of the method in Eastern Finland, where there are requirements for the simultaneous development of nature conservation, tourism, and recreation. We compiled all available ecological data sets from the study area, complemented the missing data using habitat suitability modeling, calculated the total ecological score (TES) for each 1 ha grid cell in the study area, and finally, demonstrated the use of TES in assessing the success of nature conservation in covering ecologically valuable areas and locating ecologically sustainable areas for tourism and recreational infrastructure. The method operated quite well at the level required for regional and local scale planning. The quality, quantity, availability, and usability of existing data sets were generally high, and they could be further complemented by modeling. There are still constraints that limit the use of the method in practical land use planning. However, as increasing data become available and open access, and modeling tools improve, the usability and applicability of the method will increase

Tree removal as a management strategy for the lady’s slipper orchid, a flagship species for herb-rich forest conservation

Abstract In boreal herb-rich forests, the dominance of Norway spruce (Picea abies) decreases light availability for understory species, many of which depend on canopy gaps for reproduction. Here, we explored the response of a rare clonal understory herb, the lady’s slipper orchid (Cypripedium calceolus), to tree removal. We used demographic data spanning 16 years from ten unharvested control sites and ten harvest sites which were divided into three treatments with differing harvest intensity: (1) dense spruce forests, where half of the total tree basal area (TBA) was cut, (2) sparse spruce forests, where one-fourth of the spruce TBA was cut and (3) sparse broadleaf forests, where one-fourth of the total TBA was cut. The effects of harvesting on different demographic rates (ramet density, reproduction, survival, and dormancy) were studied with generalized linear mixed models with harvest intensity, time since harvest and the starting level of the response variable as explanatory variables. Tree removal sites had 2.2 times higher orchid ramet density, 2.4 times higher odds of survival, and 2.1–3.1 times higher odds of flowering and fruiting than the control sites, but these effects were not seen at all treatment levels at all times. Tree removal had no effect on dormancy or seedling or flower density. Orchid flowering and fruiting probabilities increased only at the most intensively harvested sites (both spruce forest sites, and dense spruce forest with 50% TBA removal, respectively), while survival and ramet density increased at the moderately harvested broadleaf forest sites. The effects on flowering and fruiting probabilities and survival disappeared quickly (after three years) when the canopy gaps closed, whereas ramet density responded only with a lag of over three years and was maintained to the end of the study. Our results thus demonstrate that for the lady’s slipper orchid, selective tree harvest might be a suitable management method that increases population size at the ramet level

A novel GIS-based approach for sustainable land use planning

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