Forest ecosystems represent the most important values of natural assets. In economic valuation techniques, to estimate the value of forest ecosystem services, the attention is still focused mainly on their market values, i.e. the value of benefits measured in the economic calculation based, first of all, on the price of timber. The valuation of natural resources is currently supported by considerations of the global policy, in order to strengthen the argumentation justifying the need to incur expenditure related to the protection of biodiversity. There is increasing evidence that biodiversity contributes to forest ecosystem functioning and the provision of ecosystem services. Natural capital of forests can be consumed directly as food, wood and other raw materials or indirectly – by benefitting from purified water and air, safeguarded soils or protected climate. At the same time, forest ecosystems provide us with a range of intangible values – scientific, cultural, religious as well as encompass heritage to pass on to future generations. In the era of increasing pressure on the use of free public goods (natural resources), it is necessary to improve understanding of the role of forests in creating national natural capital, and in enhancing the quality of human life. All things considered, the so called non-market forest ecosystem services may have a much higher value than the profits from the production of timber and raw materials. Needless to say, non-market values of forest ecosystems are of great importance for the quality of human life, and the awareness of this should translate into social behavior in the use of natural resources. This paper reviews the methods to estimate the value of forest ecosystem services in view of recently acknowledged paradigm to move forward from economic production to sustainable human well-being.
Leszek Kucharski, Marek Kloss, Jadwiga Sienkiewicz, Małgorzata Liszewska and Piotr Kiełtyk
The article refers to a broader context of scientific debates on the effect of climate warming on shifts in species ranges and describes the recent changes in the distribution and life strategy of Hedera helix close to its eastern limit, in light of climate changes. European ivy is an ecotone species, occurring in fringe communities, in deciduous and mixed deciduous forests in fresh and moist habitats that are occupied by oak-hornbeam and riparian alder-ash forests in Central Poland. Since the mid-20th century, the ivy, a species rarely reproducing generatively, has become an expansive plant with a growing number of sites where flowering and fruiting individuals are encountered. We studied the distribution, habitat requirements and flowering of H. helix in Central Poland in the years 2015–2017 and compared to the situation in the mid-1970s. Climate changes in terms of average air temperatures and precipitation amounts for the past four decades were also assessed. Within the study area, 474 stands of naturally growing Hedera have recently been identified. Ivy was found to reproduce generatively on 121 of those locations. There has been an almost 10-fold increase in the number of fruiting ivy specimens since the mid-1970s of the 20th century. Changes in the species life strategy can be ascribed to the increase in both average air temperatures and solar radiation intensity observed for the past decades. Both enhanced fragmentation of woodland tracts and development of forest ecotones and forest canopy openings promote the expansion of H. helix, while its habitat preferences remain unchanged.
Jadwiga Sienkiewicz, Grażyna Porębska, Apolonia Ostrowska and Dariusz Gozdowski
Peat mineralisation leads to net loss of CO2 to the atmosphere, as well as to release of other elements from the decomposed soil organic matter (SOM) to groundwater. This results in the degradation of peat soils and the ecosystems they support. Here we evaluated the practical indicatory suitability of the existing and proposed new indices for the assessment of peat soil degradation in the Biebrza river valley encompassing, unique on European scale, peatland ecosystems. We studied relationships between soil organic carbon (SOC) and total nitrogen (Ntot), dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in a series of degraded peat soils in the Biebrza valley. Samples were taken from soils developed on peat deposits that varied in thickness and the degree of peat decomposition, from undegraded to highly mineralised peats. The relationships between changes in the SOC content and changes in the values of the remaining variables (SOM, Ntot, DOC, DON, C/N ratio), were statistically tested. Linear and non-linear regressions were used to establish the relationships amongst the variables examined. The losses of soil C and N occur independently and differ between stages of peat soil mineralisation. From our study, it results that the peat mineralisation intensity may be estimated based on the loss of SOC. We found that 1% loss of SOC corresponded to 1.028% loss of SOM, regardless of the degree of peat soil mineralisation, whereas SOM solubility, measured by the content of DOC, varied based on the intensity of peat soil mineralisation. The content of DOC decreased with the decrease in the SOC content, whereas the DOC/ SOC ratio increased depending on the intensity of peat decomposition. The C/N ratio is not a reliable indicator of peat mineralisation, because its values are driven not only by the nitrogen natively present in peat soils but also by nitrogen from external sources. The contents of SOC and Ntot did not decrease uniformly during peat decomposition because C and N show various mobility in the processes of SOM mineralisation. We found that the DOC/SOC ratio was most indicative of peat soil mineralisation intensity.