Search results for "sukupuutto"
showing 10 items of 10 documents
Wood-decaying fungi in old-growth boreal forest fragments: extinctions and colonizations over 20 years
2021
According to ecology theory, isolated habitat fragments cannot maintain populations of specialized species. Yet, empirical evidence based on monitoring of the same fragments over time is still limited. We studied the colonizationâextinction dynamics of eight wood-decaying fungal species in 16 old-growth forest fragments (<14 ha) over a 20-year period (1997â2017). We observed 19 extinctions and 5 colonizations; yet, the distribution of extinctions and colonizations did not differ from the one expected by chance for any of the species. Twenty-six percent of the extinctions took place in two natural fragments amid large forestâpeatland complexes. (Romell) Bourdot and Galzin decreased …
Resource use of wood-inhabiting fungi in different boreal forest types
2017
Generalist species are usually widespread and abundant, and thrive in heterogeneous environments. Specialists, in turn, are generally more restricted in their range, and benefit from more stable conditions. Therefore, increasing human-induced disturbance can have more negative effects on specialist than generalist species. We assessed the specialization of 77 wood-inhabiting fungal species across seven boreal forest types and different substratum qualities. A significantly higher number of specialist species was associated with herb-rich forests and afforested fields than with managed coniferous forests and wood pastures, the number of specialists associated with natural coniferous forests …
Predicting the risk of extinction from shared ecological characteristics
2005
Understanding the ultimate causes of population declines and extinction is vital in our quest to stop the currently rampant biodiversity loss. Comparison of ecological characteristics between threatened and nonthreatened species may reveal these ultimate causes. Here, we report an analysis of ecological characteristics of 23 threatened and 72 nonthreatened butterfly species. Our analysis reveals that threatened butterflies are characterized by narrow niche breadth, restricted resource distribution, poor dispersal ability, and short flight period. Based on the characteristics, we constructed an ecological extinction risk rank and predicted which of the currently nonthreatened species are at …
Patch size and connectivity influence the population turnover of the threatened chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenida…
2008
Chequered blue butterfly, Scolitantides orion (Lepidoptera: Lycaenidae) has severely declined in many parts of Europe and is currently red-listed in many countries. We studied the population structure and turnover of the species in a lake-island system in a National Park in eastern Finland over a three-year period. The incidence of the chequered blue on the suitable islands (n = 41) and habitat patches (n = 123) was high: an average of 82% of the islands and patches were occupied over the three year period. At the island scale, the annual population turnover rate was 17%, with an extinction and colonization rate of 7% and 10%, respectively. At the patch scale, the annual population turnover…
Contemporary spatial and environmental factors determine vascular plant species richness on highly fragmented meadows in Central Finland
2018
Context Habitat loss is a major threat to biodiversity. It can create temporal lags in decline of species in relation to destruction of habitat coverage. Plant species specialized in semi-natural grasslands, especially meadows, often express such extinction debt. Objectives We studied habitat loss and fragmentation of meadows and examined whether the changes in meadow coverage had caused an extinction debt on vascular plants. We also studied whether historical or present landscape patterns or contemporary environmental factors were more important determinants of species occurrence. Methods We surveyed the plant species assemblages of 12 grazed and 12 mown meadows in Central Finland and dete…
Kääväkkäiden kannanvaihtelu pirstoutuneissa vanhoissa metsissä
2019
Luonnon monimuotoisuus on tärkeää ekosysteemien ja ekosysteemipalveluiden säilymiselle, mutta maankäyttö uhkaa monien lajien selviämistä. Yksi suurimmista uhista monimuotoisuudelle on elinympäristöjen pirstoutuminen. Kääväkkäät ovat tärkeitä boreaalisten metsien puuaineksen hajottajia, mutta niiden kannanvaihteluista pirstoutuneessa metsämaisemassa tiedetään vähän. Tämän tutkielman tavoitteena oli selvittää kääväkkäiden kannanvaihteluita eristyneillä kuusivaltaisilla vanhan metsän laikuilla. Tutkimuksessa tarkastelin sekä metsälaikkujen että maisematason ominaisuuksien vaikutusta kääväkkäisiin. Keräsin aineiston Kuhmosta 16 metsälaikulta, joilla oli tehty kääväkäskartoitus vuonna 1997. Tutk…
Extinction risk indices for measuring and promoting planetary well-being
2024
The concept of planetary well-being, which stresses the persistence of lineages in ecosystems, is intimately linked to species extinction risk. Avoiding extinctions is a moral issue, as wiping out the outcomes of eons of evolutionary history and their future potential is clearly unconscionable. The concept of planetary well-being is also systemic: It is understood that species, as integral parts of ecosystems, are vital for the well-being of all systems on Earth. Yet, despite international agreements to protect biodiversity, global biodiversity loss and ecosystem degradation has continued unimpeded over the past decades. We review the role of goals and targets in the UN Convention on Biolog…
Buffer strips can pre-empt extinction debt in boreal streamside habitats
2013
Background. Conservation of biological diversity and economical utilization of natural resources form an almost inevitable confrontation between the two. In practice, however, a balance between the two ought to be found, and in managed boreal forests, preservation of woodland key habitats is increasingly used strategy to safeguard biological diversity. According to the Finnish Forests Act, certain Forest Act habitat (FAH) types must be safeguarded, provided they are clearly distinguishable from their surroundings. Furthermore, once the habitat has been identified as a FAH, its special characteristics must not be altered. Both of these aspects contain ambiguities that potentially undermine t…
Verifying the predicted risk of extinction based on ecological characteristics
2021
Red List status of species should reflect species extinction risk. Because data are limited and species response has a time lag, species may be threatened by extinction even if they are not Red‐Listed. The ability to predict species risk of extinction from ecological characteristics holds promises for proactively targeting conservation measures to species at high risk. In 2005, the risk of extinction from ecological characteristics was predicted for 81 species of Finnish butterflies. Now, after 15 years and two additional national Red List assessments, these predictions are verified. Species with a higher risk of extinction according to the original ecological extinction risk rank (EERR) ha…
Alarmist by bad design: Strongly popularized unsubstantiated claims undermine credibility of conservation science
2019
&amp;ldquo;Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades.&amp;rdquo; or &amp;ldquo;Our work reveals dramatic rates of decline that may lead to the extinction of 40% of the world&amp;#39;s insect species over the next few decades.&amp;rdquo; These are verbatim conclusions of the recent paper by S&amp;aacute;nchez-Bayoa and Wyckhuys (2019) in Biological Conservation. Because of fundamental methodological flaws, their conclusions are unsubstantiated. Like noted by The Guardian, the conclusions of the paper were set out in unusually forceful terms for a peer-reviewed scientific paper. The current case…