Clearcutting forestry and Eurasian boreal forest grouse: Long-term monitoring of sympatric capercaillie Tetrao urogallus and black grouse T. tetrix reveals unexpected effects on their population performances     

Per Wegge  Jørund Rolstad 《Forest Ecology and Management》2011,261(9):1520-1529

Along the succession gradient of the boreal forest ecosystem, black grouse Tetrao tetrix inhabits the early and capercaillie Tetrao urogallus the latest stages. When converting old forest to clearcuts and plantations, commercial forestry has therefore been assumed to affect capercaillie negatively and to be favourable to black grouse. During a 30-year period (1979-2008) we monitored sympatric populations of the two species in a forest in southeast Norway based on annual spring and autumn censuses and radio-marked birds. During this period, the proportion of old, semi-natural forest was halved and clearcuts and young plantations increased accordingly. The grouse populations did not change as predicted. While the trend in August numbers of adult black grouse declined, males more than females, abundance of adult capercaillie remained unchanged. Number of males at leks showed similar patterns. Equally surprising, breeding success (number of chicks per female in August) of both species increased, thus indicating that the populations were regulated more by variation in adult survivorship than by recruitment of young birds. No correlations were found with changing climatic factors (precipitation and temperatures in winter and spring, snow depth and time of snow melt), except that year-to-year breeding success was positively correlated with minimum temperatures during 2 weeks posthatch. The results are explained by a combination of more flexible habitat selection than previously assumed and a changing predator regime: In the early period, nearly all capercaillie leks were located in old, semi-natural forest, but as plantations grew older (>30 years), new leks were established there. Similarly, while young capercaillie broods used old semi-natural forest almost exclusively when the study started, they frequently used middle-aged plantations, especially those with a ground cover of bilberry Vaccinium myrtillus, when these became common in later years. The increasing breeding success could largely be explained by more females rearing chicks successfully, presumably due to a marked decline in the main nest predator, the red fox Vulpes vulpes. A practice of thinning of the old, semi-natural forest some years prior to final harvesting probably facilitated predation of black grouse by goshawks Accipiter gentilis. Contrary to many beliefs, our results indicate that both capercaillie and black grouse are quite tolerant to changes in forest management regimes. In our study, numerical and functional responses of predators (mainly red fox and goshawk) apparently played a more important role in regulating grouse numbers than habitat factors per se.  相似文献   

Atmospheric deposition and leaching of nitrogen in Chinese forest ecosystems     

Yunting?FangEmail author  Per?Gundersen  Rolf?D.?Vogt  Keisuke?Koba  Fusheng?Chen  Xi?Yun?Chen  Muneoki?Yoh 《Journal of Forest Research》2011,16(5):341-350

Data have been compiled from published sources on nitrogen (N) fluxes in precipitation, throughfall, and leaching from 69 forest ecosystems at 50 sites throughout China, to examine at a national level: (1) N input in precipitation and throughfall, (2) how precipitation N changes after the interaction with canopy, and (3) whether N leaching increases with increasing N deposition and, if so, to what extent. The deposition of dissolved inorganic N (DIN) in precipitation ranged from 2.6 to 48.2 kg N ha⁻¹ year⁻¹, with an average of 16.6 kg N ha⁻¹ year⁻¹. Ammonium was the dominant form of N at most sites, accounting for, on average, 63% of total inorganic N deposition. Nitrate accounted for the remaining 37%. On average, DIN fluxes increased through forest canopies, by 40% and 34% in broad-leaved and coniferous forests, respectively. No significant difference in throughfall DIN inputs was found between the two forest types. Overall, 22% of the throughfall DIN input was leached from forest ecosystems in China, which is lower than the 50–59% observed for European forests. Simple calculations indicate that Chinese forests have great potential to absorb carbon dioxide from the atmosphere, because of the large forest area and high N deposition.  相似文献   

Recovering decomposing plant residues from the particulate soil organic matter fraction: size versus density separation   总被引：2，自引：0，他引：2  

J. Magid  Charlotte Kjærgaard 《Biology and Fertility of Soils》2001,33(3):252-257

 A detailed size separation of particulate organic matter (POM) from soils amended with straw from Hordeum vulgare or Vicia sativa revealed that the loss of C during the first 56 days of incubation mainly occurred from particles >2,000 μm, without a concomitant reduction in the size of these large particles. Preliminary studies of POM from non-amended soil had shown that the stable heavy (>1.4 g cm^–3) POM fraction was mainly (>80%) composed of particles <400 μm, whereas the light fraction was dominated by larger particles (>80%). Therefore we decided to compare the POM <1.4 g cm³ with POM >400 μm. There was a very close relationship between POM>400 μm and POM <1.4 g cm^–3 with regard to amounts of C and N, as well as the appearance of these fractions under the microscope. Similarly there was a close relationship between changes in the C content of the POM fractions and the CO₂ respired, and this was also the case when comparing changes in POM-N with net N mineralization. This indicated that the biological activity during decomposition was actually localized in the POM. Due to the lighter workload and lower expenditure for reagents in connection with size separation of POM, we recommend the size separation procedure in connection with studies of residue decomposition in arable systems. Received: 23 May 2000  相似文献   

Developing a kinetic alternative in modeling soil aluminium     

Mattias Alveteg  Harald Sverdrup  Per Warfvinge 《Water, air, and soil pollution》1995,79(1-4):377-389

Soil chemistry models often use gibbsite solubility and similar equilibrium models to predict Al concentrations in soil solution. A kinetic alternative was developed with the goal of finding universal rate constants instead of the site- and depth-specific solubility constants usually associated with the equilibrium approach. The behavior of the two approaches was studied within the framework of the steady-state soil chemistry model PROFILE using data from Solling, Germany and Gårdsjön, Sweden, two sites with different mineralogy and land use history. The kinetic alternative uses a mass balance to predict Al concentrations. The sources of Al in soil water are deposition, weathering and mineralization. The sinks are leaching and the formation of an aluminosilicate precursor. The precursor slowly transforms into an ordinary clay mineral. Both formation and transformation of the precursor are treated as irreversible processes. The kinetic model introduces a new relationship between pH and Al and produces a systematic pattern of different apparent gibbsite equilibrium constants at different depths. Results show that the kinetic model systematically underestimates Al concentration in the upper horizons, which indicates that there may be additional sources of Al in the upper horizons not accounted for in the model. Predicted values of pH and Al concentrations are comparable with field observations.  相似文献   

How to cut world hunger in half     

Lindskog P 《Science (New York, N.Y.)》2005,310(5755):1768

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Anthocyanin characterization utilizing liquid chromatography combined with advanced mass spectrometric detection     

Steimer S  Sjöberg PJ 《Journal of agricultural and food chemistry》2011,59(7):2988-2996

Anthocyanins are naturally occurring polyphenolic plant pigments. To analyze the anthocyanin content of samples, rapid and reliable methods for separation and detection are needed. In this work an LC-DAD-ESI-MS/MS instrument was used to develop a new tandem MS data acquisition strategy for anthocyanin characterization which was subsequently compared to more conventional measurements. It has been shown that the newly developed strategy, multiple reaction monitoring-initiated anthocyanin characterization (MIAC), can successfully be used in anthocyanin analysis and has various advantages compared to some more traditional measurements, such as enhanced selectivity, better signal-to-noise ratio and simplified data evaluation. Furthermore, the number of relevant MS/MS data increased significantly with the MIAC method compared with a more common information dependent MS experiment strategy.  相似文献   

Ion Leaching Before and After Clear-Cutting in a Norway Spruce Stand - Effects of Long-Term Application of Ammonium Nitrate and Superphosphate     

Berdén  Maria  Nilsson  S. Ingvar  Nyman  Per 《Water, air, and soil pollution》1997,93(1-4):1-26

Soil solution chemistry was measured in a Haplic Podzol in a Norway spruce (Picea abies, L.Karst) site in central Sweden that had received frequent low-dose applications of nitrogen (N) asammonium nitrate (30-120 kg N/ha yr) and phosphorus (P) as superphosphate (20-40 kg P/haabout every third year) over a long period (22 yr). The aim was to investigate effects of added Non the ion leaching before and after clear-cutting. The N load corresponded well with actual loadsin central Europe. Prior to clear-cutting, fertilization increased concentrations of several ions inthe soil solution. Total losses of NO ₃ ^- , Al andH⁺ increased with the intensity of fertilization. However, since fertilization enhanced tree growthand nutrient uptake, differences between the total losses of several other ions tended to beequalized. After clear-cutting, the pH in the soil solution decreased, and the losses of Mn and Alincreased with fertilizer load, probably because of increased N mineralization and nitrification. Inthe N treatments the concentration of SO ₄ ^2- in the soil solution decreased, probably owing toincreased adsorption in the B horizon in response to the pH decrease. The effects ofanthropogenic N deposition are discussed in the light of our findings and possible causes oftemporal and spatial variation in soil solution chemistry and ion fluxes are suggested.  相似文献   

The role of weathering and forestry in determining the acidity of Lakes in Sweden     

Harald Sverdrup  Per Warfvinge 《Water, air, and soil pollution》1990,52(1-2):71-78

The long term acidity level of a lake is determined by the balance between acidity input to the catchment and the generation of alkalinity in the catchment. If the input of acidity through biomass net production and the production of alkalinity through weathering of minerals can be estimated, then the steady-state acidity level can be calculated for the lake under a certain acid deposition rate. Such a calculation has been carried out for 8 lakes ranging from acid to neutral. For lakes with the most sensitive soils in the catchment, the critical acid deposition load that will permit the lake to stay neutral, may be less than zero acidity, indicating that the forest growth is contributing to the acidification of very sensitive system under the present forest managements methods.  相似文献   

Aluminium sulphate solubility in acid forest soils in Denmark     

Per Gundersen  Claus Beier 《Water, air, and soil pollution》1988,39(3-4):247-261

Ion leaching in 3 sandy spruce forest soils of different origin and pH was investigated in the laboratory. Zero-tension lysimeters containing undisturbed soil columns of varying soil depth were subjected to H₂SO₄ loadings for a period of 9 weeks. The analysis of the resulting leachate supports the hypothesis that Al-sulphate minerals may form in acidic soils when exposed to acid (H₂SO₄) deposition. In the B horizon of a glaciofluvial sandy soil (pH 4.2), both H⁺ and sulphate ions were retained to maintain 2pH + PSO₄ = 11.9 in the leachate solutions. This relation between H⁺ and sulphate activity may be due to an adsorption mechanism or a precipitation mechanism. The precipitation mechanism is favored by the good fit of leachate composition to the conditions for jurbanite [AlOHSO₄] formation from gibbsite [Al(OH)₃]. In the B horizon of a sandy till at pH 3.7, the Al in soil solution (0.5 mmol L^?1) was leached with sulphate. As the sulphate load was increased, some sulphate was retained. This may also be due to the dissolution and precipitation of an Al-sulphate mineral. The ion activity products of leachate solutions from the B horizon of this soil were close to the pK_s reported for jurbanite. The conditions for the possible existence and/or formation of Al-sulphate minerals in acidic soils are discussed.  相似文献   

Nutrient and persistent pollutant deposition on the Bothnian Bay ice and snow fields     

Lars Rahm  Bertil Håkansson  Per Larsson  Elisabet Fogelqvist  Gudrun Bremle  Jorge Valderrama 《Water, air, and soil pollution》1995,84(1-2):187-201

A study of atmospheric deposited nutrients and some persistent pollutants has been carried out on the ice and snow fields of the subarctic Bothnian Bay, the northernmost basin of the Baltic Sea. Total amounts of 600, 500 and 400 tons NO₃-N, NH₄-N and N_org-N, respectively are deposited in the snow while the corresponding amounts for P_tot-P is 40 tons. The corresponding amount for PCB and lindane are 1.0 and 0.2 kg, respectively. The measurements were carried out on the snow-covered ice four to six weeks old. A part of the deposited snow has been incorporated -into the snow-ice and an attempt to estimate its mean thickness and its amount of nutrients has been made. The total amounts now reach 1700, 1300 and 1100 tons of NO₃-N and NH₄-N and N_org-N, respectively in the snow and ice together. The results obtained support the use of land-based stations in estimates of seasonal atmospheric nutrient deposition to the Bothnian Bay. The observed concentrations of chloroorganic compounds correspond to those land-based observations reported from the same latitude in the northern hemisphere and reported in literature.  相似文献