Forest Cover Development Research Articles

Характер розташування лісів на водозборі гірської річки в Карпатах як один з чинників формування витрат води весняного водопілля

Оцінено можливість застосування показника розвитку лісистості водозбирання ε для характеристики розташування лісів на ньому. Встановлено малу інформативність ε для лісогідрологічних досліджень. Проаналізовано опубліковані експериментальні дослідження та матеріали Закарпатської воднобалансової станції про вплив хвойних і листяних лісів на величину снігонакопичення та інтенсивність сніготанення в Карпатах. Вивчено морфометричні характеристики досліджуваного водозбору річки Яблунька до м. Турка в Бескидах, розташування лісів на ньому, їх породний і віковий склад. Площа водозбору 136 км2, середня висота н.р.м. 722 м. Максимальний час добігання води до створу τ = 6 год. Лісистість водозбору 30,0 %, 95 % площі займають деревостани з переважанням ялини європейської та ялиці білої. При різному розташуванні лісів на цьому водозборі змодельовано погодинну витрату води на підйомі гідрографу для типового температурного режиму в період весняного сніготанення. Встановлено, що для малих водозборів, де τ у десятки разів менший від часу сніготанення, характер розташування лісів не відіграє значної ролі у формуванні середньогодинних витрат води. Різниця між витратами води весняного водопілля для різних варіантів розташування лісів, спричинена відтермінуванням початку сніготанення у хвойних лісах, не перевищує 10 %. За синхронної зміни інтенсивності сніготанення в лісі та на відкритих ділянках різниця між витратами води для різного розташування лісів становить 1–3 %; за асинхронної зміни – 3–7 %.

Afforestation or natural succession? Looking for the best way to manage abandoned cut-over peatlands for biodiversity conservation

We investigated the plant species diversity in patches with natural non-forest vegetation (NN), with forest communities that had developed where there was a spontaneous succession of vegetation (called: natural forests, NF), and with planted forests (PF) within cut-over peatlands located in central Poland. We studied (1) how diverse is plant composition in actively managed and in abandoned cut-over peatland areas, (2) how does afforestation influence wetland species composition, and (3) does natural plant succession in abandoned cut-over peatlands favour peatland regeneration and the maintenance of typical peatland species. We also defined the ecosystem services (with special attention to supporting services) and we analysed the conflicts and synergies of two cut-over peatland utilization options (abandonment and conventional forestry).An ANOVA test was used to analyse statistical differences in the diversity index, phytosociological units and Ellenberg index. Ecological conditions of NN, NF and PF were described on the base of Ellenberg indicator values (EIVs). A modified permutation test using mean randomized EIVs was used to check the significant differences in Ellenberg values.The results show that the vegetation of NN, NF and PF areas differ significantly in mean number of species, Shannon diversity and evenness index. The analyses of Ellenberg values indicated that the light and moisture conditions of NN, NF and PF differ markedly. The development of forest cover, both natural and anthropogenically created, leads to an increase in plants species diversity. However, the encroachment of numerous shade-tolerant forest species does not compensate for the reduction in characteristic peatland species. The afforestation of degraded peatland areas may be an option for management, but in every single case the decision for afforestation ought to be preceded by the recognition of the initial state of the species richness of degraded and potentially managed wetland. The most valuable wetlands with preserved peatlands flora should be actively restored for biodiversity conservation.

Population increase of forest birds in the Czech Republic between 1982 and 2003

Capsule Populations of most forest bird species increased between 1982 and 2003, probably due to increased forest cover and changes in forest age-class composition. Aims To determine population changes of forest birds in the Czech Republic and to determine their possible causes. Methods Population data were collected via the Breeding Bird Monitoring Programme, which is based on skilled volunteers counting birds at point transects using a standardized technique. Population trends and indices for the period 1982–2003 were calculated for 47 species using log-linear models. Published data on development of forest cover and forest age composition in the Czech Republic were used to indicate environmental change over the same period. Results Populations of most forest species increased between 1982 and 2003. There was also an increase in forest cover and an increase in the proportion of older forest age-classes. The increase in forest specialist birds was positively correlated with the average increase in forest coverage. Conclusions The populations of Czech forest birds have increased in the last two decades. This contrasts with widely reported declines of farmland bird populations throughout Europe. The correlation between populations of specialized forest species and extent of forest habitat suggests that changes in land-use are an important factor. However, increasing cover of mature forests could have a similar effect on the populations of specialist species.

Paleolimnological evidence for increased landslide activity due to forest clearing and land-use since 3600 cal BP in the western Swiss Alps

Schwarzsee is located in the western Swiss Alps, in a region that has been affected by numerous landslides during the Holocene, as evidenced by geological surveys. Lacustrine sediments were cored to a depth of 13 m. The vegetation history of the lake's catchment was reconstructed and investigated to identify possible impacts on slope stability. The pollen analyses record development of forest cover during the middle and late Holocene, and provide strong evidence for regional anthropogenic influence such as forest clearing and agricultural activity. Vegetation change is characterized by continuous landscape denudation that begins at ca. 4300 cal. yrs BP, with five distinct pulses of increased deforestation, at 3650, 2700, 1500, 900, and 450 cal. yrs BP. Each pulse can be attributed to increased human impact, recorded by the appearance or increase of specific anthropogenic indicator plant taxa. These periods of intensified deforestation also appear to be correlated with increased landslide activity in the lake's catchment and increased turbidite frequency in the sediment record. Therefore, this study gives new evidence for a strong influence of vegetation changes on slope stability during the middle and late Holocene in the western Swiss Alps, and may be used as a case study for anthropogenically induced landslide activity.