Planted forests and biodiversity

Expansion of planted forests and intensification of their management has raised concerns among forest managers and the public over the implications of these trends for sustainable production and conservation of forest biological diversity. We review the current state of knowledge on the impacts of plantation forestry on genetic and species diversity at different spatial scales and discuss the economic and ecological implications of biodiversity management within plantation stands and landscapes. Managing plantations to produce goods such as timber while also enhancing ecological services such as biodiversity involves tradeoffs, which can be made only with a clear understanding of the ecological context of plantations in the broader landscape and agreement among stakeholders on the desired balance of goods and ecological services from plantations.

Effects of fire on the structure and composition of open eucalypt forests

Fires are integral to the healthy functioning of most ecosystems and are often poorly understood in policy and management, however, the relationship between floristic composition and habitat structure is intrinsically linked, particularly after fire. The aim of this study was to test whether the variability of habitat structure or floristic composition and abundance in forests at a regional scale can be explained in terms of fire frequency using historical data and experimental prescribed burns. We tested this hypothesis in open eucalypt forests of Fraser Island off the east coast of Australia. Fraser Island dunes show progressive stages in plant succession as access to nutrients decreases across the Island. We found that fire frequency was not a good predictor of floristic composition or abundance across dune systems; rather, its affects were dune specific. In contrast, habitat structure was strongly influenced by fire frequency, independent of dune system. A dense understorey occurred in frequently burnt areas, whereas infrequently burnt areas had a more even distribution of plant heights. Plant communities returned to pre-burn levels of composition and abundances within 6 months of a fire and frequently burnt areas were dominated by early successional species of plant. These ecosystems were characterized by low diversity and frequently burnt areas on the east coast were dominated by Pteridium. Greater midstorey canopy cover in low frequency areas reduces light penetration and allows other species to compete more effectively with Pteridium. Our results strongly indicate that frequent fires on the Island have resulted in a decrease in relative diversity through dominance of several species. Prescribed fire represents a powerful management tool to shape habitat structure and complexity of Fraser Island forests.

Mapping mosquito breeding habitats (water) under mangrove canopy: contribution from airborne thermal scanning

Proceedings of the 11th Australasian Remote Sensing and Photogrammetry Conference

Stylization: a method for preserving the character of climate sensitive habitats. A case study of acidofrequent mixed forests

Stylization is a common method of ornamental plant use that imitates nature and evokes the scenery. This paper discloses a not yet proposed aspect of stylization, since the method offers the possibility of preserving the physiognomy of those habitats that seem to vanish due to future climate change. In addition, novelty of the method is founded also on that vulnerability of the Hungarian habitats has been examined by the researchers only from the botanical and ecological point of view so far and not in terms of its landscape design value. In Hungary, acidofrequent mixed forests appear to be highly sensitive to climate change according to ecological models. We are going to discuss the methodology of stylization of climate sensitive habitats and briefly refer to acidofrequent mixed forests as a case study. Those coniferous and deciduous tree species of the studied habitat that are water demanding are proposed to be substituted by drought tolerant ones with similar characteristics, and an optionally expandable list of these taxa is presented. Based on this the authors suggest experimental investigations of those of the proposed taxa for which the higher drought tolerance is based on observations only.

Natura 2000 erdők közgazdasági környezetének elemzése (Assessment of the economic environment of Natura 2000 forests)

Ebben a tanulmányban a Natura 2000 erdők közgazdasági kérdéseit jártuk körül az ökoszisztéma-szolgáltatások koncepciójának segítségével, nemzetközi és hazai szakirodalomra építve. Emellett a természetközeli erdőgazdálkodás fogalomkörét, s azon belül a folyamatos erdőborítást szolgáló erdőgazdálkodást vettük alapul. A következőkben néhány összegző megállapítást teszünk, és kijelölünk további kutatási irányokat. _____ This study has been prepared within the LIFEinFORESTS – Improved communication, cooperation and capacity building for preserving biodiversity in Natura 2000 forests (B2 action, LIFE13 INF/HU/001163) – project in the framework of LIFE+ Information and Communication under the contract signed with the Duna-Ipoly National Park Directorate. The main aim of the study is to summarize the international and Hungarian economic and environmental economic literature related to the Natura 2000 forests, and serve as a background study for the communication with and training of forest owners and users operating at Natura 2000 sites. The concept of ecosystem services (ESs) is used as an overall framework for the study. In our opinion it is able to show all the benefits provided by forests and can also help to reveal that the benefits of nature-oriented, continuous cover forest management (CCF) can exceed the benefits of traditional rotation forest management (RFM). The definition and the classification of the Millennium Ecosystem Assessment (MA, 2003, 2005) is used throughout the study, so provisioning, cultural, regulating and supporting services are distinguished.

Effects of light quantity and quality on early seedling development in the red mangrove Rhizophora mangle L

Seedlings of the red mangrove, Rhizophora mangle L., were grown under light conditions differing in both photosynthetic photon flux density (PPFD) and spectral quality (red:far-red ratio, R:FR). During the first 8 mo of development, parameters of stem, leaf, and root growth were affected by PPFD. Significant responses to lowered R:FR, however, were limited to internode extension. The results are moderately indicative of a strategy to persist in shade, but illustrate the complexity of light responses and suggest that precise categorization as shade-tolerant or -intolerant may be unbefitting for this species at this particular stage of development.

Human disturbance and forest diversity in the Tansa Valley, India

We assessed the diversity of woody plants at 15 forested sites in the Tansa Valley of Thane District, in Maharashtra, India. The fewest species (11) were seen at a degraded mangrove site near the river mouth, and the greatest number (150) in the rich semi-evergreen forest on Tungar Hill. For all sites there were 141 tree, 25 shrub and 15 liana species, a total of 181 species. Excluding the mangrove site, which had no species in common with the other 14 sites, we analyzed the species distributions in detail. 2 These sites ranged in area from 4 to 30 km each, had woody floras of 89 6 6 species, and varied in intensity of human impact. Despite a history of exploitation and substantial reduction in biomass from firewood collecting, set fires and illicit tree felling, considerable plant diversity remains in the area.We found a modest increase in species richness in transects away from two villages. We observed the exploitation of the forest by the principal users, primarily of the Warli Tribe. They exploited a wide variety of forest resources (92 species), for medicines, foods, construction materials, household goods, manure and other purposes. They collected 15 items for sale. By far the single most important item collected was firewood, which dramatically reduced forest biomass within 2 km of villages. The species distributions in these forest remnants are strongly nested, mostly due to varying degrees of disturbance at individual sites. The high species diversity on Tungar Hill is most likely a relict of the earlier character of forests throughout much of the valley. It merits the highest priorities for preservation, as a refuge for Western Ghat species at the northern limits of their distributions.

Soil carbon dynamics in primary and secondary tropical forests in Colombia

Soils play a central role in the dynamics of biospheric carbon and in climate change. They contain the largest carbon stock of terrestrial ecosystems and return to the atmosphere a significant proportion of carbon fixed by photosynthesis. Soils of tropical forests are tremendously important in the carbon cycle because they receive the largest organic matter inputs, they have the largest respiration rates, and they are among the largest carbon reservoirs among world soils. This research assesses the main components of the soil carbon dynamics in primary (PF) and secondary (SF) tropical forests in Colombia. I evaluated the production, stocks, and decomposition rates of aboveground detritus as well as the stocks, growth, mortality, and decomposition of fine roots in these two forest types. Soil carbon outputs were evaluated as total soil, heterotrophic, and root respiration. The stocks of soil organic carbon down to 4 m deep in these two cover types and in degraded pastures (PAS) were also evaluated. ^ Soil inputs of organic carbon from above and belowground sources were lower in SF than in PF. Litterfall in SF was 58% and production of fine root detritus was 60% of that in PF. When production of woody detritus and palm fronds was considered, the difference between these forest types was even larger. However, outputs of mineral carbon through heterotrophic soil respiration were similar; in SF they equaled 97% of those in PF. As a result, soil carbon balance was positive in PF and negative in SF. Despite that soil carbon balances suggest that soils of SF are losing carbon, soil carbon stocks of SF were higher than of degraded pastures, suggesting that they have already started to recover soil carbon stocks lost under degraded pastures. This discrepancy can be partially explained by the effect of drier conditions on heterotrophic soil respiration as a consequence of a moderate El Niño event during the period of soil respiration measurements. The positive carbon balance in soils of PF despite the El Niño event, suggests that soils of PF accumulated about 664 Kg C ha−1 yr−1. Therefore, soil carbon dynamics mainly depended on successional status of vegetation and on climatic conditions. ^