scholarly journals Effects of clear-cutting and selective felling in Swedish Boreal coniferous forest: response of invertebrate taxa eaten by birds

1995 ◽  
Vol 6 (2-3) ◽  
pp. 79-90 ◽  
Author(s):  
Ola Atlegrim ◽  
Kjell Sjöberg
Keyword(s):  
Indirect Effects ◽  
Abiotic Factors ◽  
Coniferous Forest ◽  
Bird Species ◽  
Sun Exposure ◽  
Total Biomass ◽  
Insectivorous Birds ◽  
Short Term ◽  
Field Layer ◽  
Clear Cutting

Our aim was to analyse the short-term effects (0-4 years) of selective felling and clear-cutting on the food resources of insectivorous birds. Literature data on bird diets showed that herbivorous larvae (Lepidoptera and Hymenoptera: Symphyta) and spiders (Araneae) were used by 81 and 50%, respectively, of 16 bird species breeding in the Swedish boreal coniferous forest. A field study comparing selective fellings, clear-cuttings and uncut controls showed considerable effects of clear-cutting on both terricolous and field layer invertebrates. Clear-cuttings had significantly lower abundance and biomass, and a different composition of herbivorous larvae and spiders, as well as a lower total biomass of invertebrates in the field layer than controls. Drastic changes of abiotic factors (like increased temperature range) following clear-cutting may directly affect the occurrence of invertebrates. However, indirect effects (like increased sun exposure, affecting food plant quality for herbivorous larvae) are probably also responsible. Selective fellings did not differ from controls in the occurrence of herbivorous larvae and spiders. Therefore, over the four-year term of our study, selective felling seems to provide birds with conditions similar to uncut forest for invertebrates used by birds.

Effects of clear-cutting on the composition of bacterial populations of northern spruce forest soil

1977 ◽  
Vol 23 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Seppo Niemelä ◽  
Veronica Sundman
Keyword(s):  
Forest Soil ◽  
Heterotrophic Bacteria ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Layer ◽  
Population Characteristics ◽  
Short Term ◽  
Biochemical Tests ◽  
Clear Cutting ◽  
Humus Layer

This paper concerns the microbiological part of an investigation, the goal of which is to describe the biological changes in coniferous forest soil upon clear-cutting in a northern (66°20′ N) moraine area where reforestation after clear-cutting had been met with difficulty. The zoological part of the work has been published elsewhere. Clear-cut sites of increasing age (4, 7, and 13 years) were investigated and compared with a forest area where no cutting of timber had been done for 120 years.A total of 684 random isolates of heterotrophic bacteria from pooled samples of the sites investigated were passed through 36 biochemical tests. The data were condensed by the aid of factor analysis, and a comparison of the populations was based on squared Euclidean distances between population centroids in a seven-dimensional factor space.The most marked population changes followed a course in which frequencies of some population characteristics became increasingly different until 7 years after clear-cutting, with regression towards the control clearly evident after 13 years. Disturbances of shorter duration were also relatively common, with maximal changes observed in the 4-year samples, and with a complete recovery after 7 years.The mineral soil populations seemed to undergo greater changes than the humus populations.The most distinct changes believed to be due to clear-cutting were the short-term relative increase of organisms producing acid from sucrose and dissolving CaHPO4, and a long-term increase of lipolytic and caseolytic, rhamnose-negative organisms; both in the mineral soil layer. In the humus layer, a short-term increase of lipolytic and of rhamnose-positive organisms seemed to take place.

scholarly journals Effect of a temperature gradient on Sphagnum fallax and its associated living microbial communities: a study under controlled conditions

2011 ◽  
Vol 57 (3) ◽  
pp. 226-235 ◽  
Author(s):  
Vincent E.J. Jassey ◽  
Daniel Gilbert ◽  
Philippe Binet ◽  
Marie-Laure Toussaint ◽  
Geneviève Chiapusio
Keyword(s):  
Climate Change ◽  
Temperature Gradient ◽  
Microbial Communities ◽  
Indirect Effects ◽  
Abiotic Factors ◽  
Testate Amoebae ◽  
Trophic Relationships ◽  
Total Biomass ◽  
Food Web Structure ◽  
Web Structure

Microbial communities living in Sphagnum are known to constitute early indicators of ecosystem disturbances, but little is known about their response (including their trophic relationships) to climate change. A microcosm experiment was designed to test the effects of a temperature gradient (15, 20, and 25 °C) on microbial communities including different trophic groups (primary producers, decomposers, and unicellular predators) in Sphagnum segments (0–3 cm and 3–6 cm of the capitulum). Relationships between microbial communities and abiotic factors (pH, conductivity, temperature, and polyphenols) were also studied. The density and the biomass of testate amoebae in Sphagnum upper segments increased and their community structure changed in heated treatments. The biomass of testate amoebae was linked to the biomass of bacteria and to the total biomass of other groups added and, thus, suggests that indirect effects on the food web structure occurred. Redundancy analysis revealed that microbial assemblages differed strongly in Sphagnum upper segments along a temperature gradient in relation to abiotic factors. The sensitivity of these assemblages made them interesting indicators of climate change. Phenolic compounds represented an important explicative factor in microbial assemblages and outlined the potential direct and (or) indirect effects of phenolics on microbial communities.

Die Brutvogelfauna eines Nadelwaldes der nördlichen Voralpen nach dem Sturm Lothar

2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer
Keyword(s):  
Forest Succession ◽  
Coniferous Forest ◽  
Bird Species ◽  
Individual Species ◽  
Mountain Forest ◽  
Breeding Bird ◽  
Point Counts ◽  
Federal Institute ◽  
Central Switzerland ◽  
Bird Fauna

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.

scholarly journals The Effects of Biotic and Abiotic Factors on the Community Dynamics in a Mountain Subtropical Forest

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 427
Author(s):  
Tianyang Zhou ◽  
Jiaxin Zhang ◽  
Yunzhi Qin ◽  
Mingxi Jiang ◽  
Xiujuan Qiao
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Forest Dynamics ◽  
Community Dynamics ◽  
Abiotic Factors ◽  
Subtropical Forest ◽  
Above Ground Biomass ◽  
Short Term ◽  
Forest Ecosystem Services ◽  
Number Of Individuals

From supporting wood production to mitigating climate change, forest ecosystem services are crucial to the well-being of humans. Understanding the mechanisms that drive forest dynamics can help us infer how to maintain forest ecosystem services and how to improve predictions of forest dynamics under climate change. Despite the growing number of studies exploring above ground biomass (AGB) dynamics, questions of dynamics in biodiversity and in number of individuals still remain unclear. Here, we first explored the patterns of community dynamics in different aspects (i.e., AGB, density and biodiversity) based on short-term (five years) data from a 25-ha permanent plot in a subtropical forest in central China. Second, we examined the relationships between community dynamics and biodiversity and functional traits. Third, we identified the key factors affecting different aspects of community dynamics and quantified their relative contributions. We found that in the short term (five years), net above ground biomass change (ΔAGB) and biodiversity increased, while the number of individuals decreased. Resource-conservation traits enhanced the ΔAGB and reduced the loss in individuals, while the resource-acquisition traits had the opposite effect. Furthermore, the community structure contributed the most to ΔAGB; topographic variables and soil nutrients contributed the most to the number of individuals; demographic process contributed the most to biodiversity. Our results indicate that biotic factors mostly affected the community dynamics of ΔAGB and biodiversity, while the number of individuals was mainly shaped by abiotic factors. Our work highlighted that the factors influencing different aspects of community dynamics vary. Therefore, forest management practices should be formulated according to a specific protective purpose.

scholarly journals Validation and Use of a Semidistributed Hydrological Modeling System to Predict Short-Term Effects of Clear-Cutting on a Watershed Hydrological Regime

2004 ◽  
Vol 8 (3) ◽  
pp. 1-19 ◽  
Author(s):  
Martin-Pierre Lavigne ◽  
Alain N. Rousseau ◽  
Richard Turcotte ◽  
Anne-Marie Laroche ◽  
Jean-Pierre Fortin ◽  
...  
Keyword(s):  
Hydrological Modeling ◽  
Hydrological Regime ◽  
Short Term ◽  
Clear Cutting ◽  
Short Term Effects

scholarly journals Power line routing and configuration as major drivers of collision risk in two bustard species

Oryx ◽  
2020 ◽  
pp. 1-10 ◽  
Author(s):  
Ana Teresa Marques ◽  
Ricardo C. Martins ◽  
João Paulo Silva ◽  
Jorge M. Palmeirim ◽  
Francisco Moreira
Keyword(s):  
Abiotic Factors ◽  
Bird Species ◽  
Power Line ◽  
Power Lines ◽  
Mitigation Measures ◽  
Suitable Habitat ◽  
Collision Risk ◽  
Great Bustard ◽  
Line Configuration ◽  
Tetrax Tetrax

Abstract Collision with power lines is a major cause of mortality for many bird species. Understanding the biotic and abiotic factors that increase collision risk is therefore important for implementing mitigation measures to minimize mortality, such as power line rerouting or wire marking. Here, we used collision events registered during 2003–2015 along 280 km of transmission power lines in southern Portugal to analyse spatio-temporal patterns and collision risk factors in two sympatric, threatened, and collision-prone species: the great bustard Otis tarda and the little bustard Tetrax tetrax. The occurrence of collisions was not uniform across space and time, and variations could be explained by the species' ecological requirements, distribution patterns and behaviour. Although both species fly considerable distances between areas of suitable habitat, collisions were far more likely in power line sections with > 20% (for the little bustard) or > 50% (for the great bustard) of open farmland habitat in the surroundings. Power line configuration was also important: taller pylons and those with a higher number of wire levels posed a higher risk for both species. Wire marking had a small but significant effect for the little bustard, reducing collisions risk. There was, however, no similar effect for the great bustard, possibly a result of limited data. Mitigation measures should be implemented to prevent bustard collisions, including adequate route planning, ideally avoiding areas with > 20% of open habitat. Line configuration and wire marking are particularly important where such localities cannot be avoided and power lines cross areas with a high proportion of bustard habitat, including outside protected areas.

Soil net methane uptake rates in response to short-term litter input change in a coniferous forest ecosystem of central China

2019 ◽  
Vol 271 ◽  
pp. 307-315 ◽  
Author(s):  
Junjun Wu ◽  
Meng Lu ◽  
Jiao Feng ◽  
Dandan Zhang ◽  
Qiong Chen ◽  
...  
Keyword(s):  
Forest Ecosystem ◽  
Coniferous Forest ◽  
Central China ◽  
Short Term ◽  
Litter Input ◽  
Uptake Rates ◽  
Methane Uptake

scholarly journals Does Deep-Underground Storage Stimulate the Germination of Canola (Brassica napus L.) Seed?

2020 ◽  
Vol 12 (6) ◽  
pp. 23
Author(s):  
Yuxin He ◽  
Chao Liu ◽  
Heping Xie ◽  
Jingchen Wang ◽  
Yang Wang ◽  
...  
Keyword(s):  
Seed Storage ◽  
Biomass Accumulation ◽  
Underground Storage ◽  
Total Biomass ◽  
Short Term ◽  
Hypocotyl Length ◽  
Brassica Napus L ◽  
The Earth ◽  
Deep Underground ◽  
Compensatory Effect

Agriculture is a crucial area to be considered when exploring and exploiting the use of deep-underground space. We investigated the feasibility of deep-underground seed storage by keeping canola seed in either envelopes or sealed packages at four depths below the Earth’s surface (0, 240, 690, and 1410 m) at a gold mine in northeastern China. We studied the effects of storage depth and duration by conducting germination tests with the stored seed. The results showed that the rate of germination was reduced in seed stored at deeper levels and was also lower at all depths after a more prolonged period of storage. Seeds from sealed packages exhibited better resistance to the deep-underground environment than seeds kept in envelopes. However, measurements of hypocotyl lengths and biomass accumulation revealed that the germination of seeds stored in deep-underground was initially inhibited but recovered well compared with the control as the storage depth increased. The total biomass of the hypocotyl increased as the depth of seed storage deepened, indicating the existence of a compensatory effect on seed germination. The findings suggest that short-term deep-underground storage of seeds in sealed packages would improve the germination performance of cultivated canola in terms of the hypocotyl length and biomass accumulation and might be considered as a pre-sowing strategy.

scholarly journals Possible Traffic Safety Effects of the Implementation of Section Control in Hungary

2020 ◽  
Vol 13 (4) ◽  
pp. 309-323
Author(s):  
Zsolt Sándor
Keyword(s):  
Traffic Safety ◽  
Indirect Effects ◽  
Social Cost ◽  
Cost Savings ◽  
International Studies ◽  
Direct Effects ◽  
Implementation Cost ◽  
Short Term ◽  
Environmental Loads

This article presents the anticipated safety effects of the implantation of section control in Hungary. The proposed results were originated from international studies and the local circumstances. Effects are depending on the control coverage and the magnitude of the sanctions. Direct (short term benefits) and indirect effects (long term benefits) can be identified. Direct effects are the decreasing of accident numbers, while indirect effects are the decrease of other externalities of transport like environmental loads. Based on the results the implementation cost of the enforcement system is measureable with the proposed social cost savings come from the decreasing number of accidents.

scholarly journals Are declines in insects and insectivorous birds related?

The Condor ◽  
2021 ◽  
Author(s):  
Douglas W Tallamy ◽  
W Gregory Shriver
Keyword(s):  
Plant Species ◽  
Invasive Plant ◽  
Bird Species ◽  
Insect Herbivores ◽  
Native Plant ◽  
Insectivorous Birds ◽  
Population Declines ◽  
Native Plant Species ◽  
Host Plant Specialization ◽  
Scale Population

Abstract A flurry of recently published studies indicates that both insects and birds have experienced wide-scale population declines in the last several decades. Curiously, whether insect and bird declines are causally linked has received little empirical attention. Here, we hypothesize that insect declines are an important factor contributing to the decline of insectivorous birds. We further suggest that insect populations essential to insectivorous birds decline whenever non-native lumber, ornamental, or invasive plant species replace native plant communities. We support our hypothesis by reviewing studies that show (1) due to host plant specialization, insect herbivores typically do poorly on non-native plants; (2) birds are often food limited; (3) populations of insectivorous bird species fluctuate with the supply of essential insect prey; (4) not all arthropod prey support bird reproduction equally well; and (5) terrestrial birds for which insects are an essential source of food have declined by 2.9 billion individuals over the last 50 years, while terrestrial birds that do not depend on insects during their life history have gained by 26.2 million individuals, a 111-fold difference. Understanding the consequences of insect declines, particularly as they affect charismatic animals like birds, may motivate land managers, homeowners, and restoration ecologists to take actions that reverse these declines by favoring the native plant species that support insect herbivores most productively.

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