Changing stock of biomass carbon in a boreal forest over 93 years     

Pekka E. Kauppi  Aapo Rautiainen  Kari T. Korhonen  Aleksi Lehtonen  Jari Liski  Pekka Nöjd  Sakari Tuominen  Markus Haakana  Tarmo Virtanen 《Forest Ecology and Management》2010,259(7):1239-1244

The growing stock more than doubled from 1.6 to 3.4 million m³ between 1912 and 2005 in forests on an area of 387 km² in southern Finland. The stock expansion continued for 93 years noting interim results, which were available for 1959, 1982, 1994 and 1999. Forested area in the region hardly changed. Carbon sequestration was mainly a result of a long-term recovery from forest degradation, a legacy of land use in the 18th and 19th centuries. Tree demography responded to management change especially of mature stands: Average tree size and stocking density of stands increased. On average the expanding biomass stock sequestered 18 tons C annually per km² (18 g C per m²). In comparison, the emissions of fossil carbon in the region were estimated at 12 tons C per km² (12 g C per m²) on average. However, fossil CO₂ emissions exceeded biomass sequestration in recent decades. The powerful and persistent expansion of the carbon stock was an unintended co-benefit of forestry, which was motivated by the intention to improve timber yield. On the more negative side the change in management introduced clear-cuts, and a loss of diverse elements of the pre-industrial biota.  相似文献   

Heterobasidion abietinum on Abies species in western Turkey     

H. T. Doğmuş‐Lehtijärvi  A. Lehtijärvi  K. Korhonen 《Forest Pathology》2006,36(4):280-286

Forty‐five basidiocarp specimens of Heterobasidion were collected from native Abies species in three locations in western Turkey: A. nordmanniana ssp. bornmülleriana in Bolu province, A. nordmanniana ssp. equi‐trojani in Balikesir province and A. cilicica in Antalya province. Pure cultures were isolated from the basidiocarps and identified to the species level with the aid of mating tests. All the specimens proved to belong to the species Heterobasidion abietinum. This root rot fungus is common in the forests investigated and appears to be relatively virulent on Abies in Turkey. This is the first report of H. abietinum outside Europe.  相似文献   

Occurrence of Heterobasidion basidiocarps on cull pieces of Norway spruce left on cutting areas and in mature spruce stands     

M. M. Müller  J. Heinonen  K. Korhonen 《Forest Pathology》2007,37(6):374-386

Fruiting of Heterobasidion on cull pieces and stumps of Norway spruce was investigated in cutting areas and mature spruce stands located in southern Finland. Cull pieces of variable size and showing butt rot were left on three clear‐cut areas and in one thinned stand. Additionally, a part of the cull pieces was transported to mature forest sites with closed canopy. During the succeeding 3–4 years the cull pieces were investigated annually for sporocarps of Heterobasidion, and the area of actively sporulating pore layer of each sporocarp was measured. Root bases of spruce stumps in the logging areas were excavated and sporocarps found on the stumps also measured. At the onset of the experiment, Heterobasidion spp. were isolated from 76% of the cull pieces showing butt rot; 85% of the isolates were identified as H. parviporum and 15% as H. annosum s.s. During the following 3–4 years sporocarps were found on 20% of the 1938 cull pieces where Heterobasidion butt rot was initially detected visually. Sporocarp formation was promoted by advancement of butt rot, increasing cull piece diameter and end‐to‐end ground contact, but restricted by the colonization of the cull piece by Stereum sanguinolentum. Between‐site differences were significant but could not be explained by differences in tree cover. At the end of the investigation period the average sporulating area of Heterobasidion sporocarp per metre of cull piece was higher than the average sporulating area per stump at three of four logging sites. Hence, leaving cull pieces containing Heterobasidion butt rot at logging areas in southern Finland can considerably increase local production of Heterobasidion spores.  相似文献   

Projecting global and regional outlooks for planted forests under the shared socio-economic pathways     

Korhonen  Jaana  Nepal  Prakash  Prestemon  Jeffrey P.  Cubbage  Frederick W. 《New Forests》2021,52(2):197-216

New Forests - There is rising global interest in growing more trees in order to meet growing population, climate change, and wood energy needs. Using recently published data on planted forests by...  相似文献   

Characterization and purification of the F17 adhesin on the surface of bovine enteropathogenic and septicemic Escherichia coli   总被引：13，自引：0，他引：13  

P F Lintermans  P Pohl  A Bertels  G Charlier  J Vandekerckhove  J Van Damme  J Schoup  C Schlicker  T Korhonen  H De Greve 《American journal of veterinary research》1988,49(11):1794-1799

The F17 antigen from bovine enterotoxigenic Escherichia coli strain (E coli 25KHO9), which adhered to calf intestinal villi, was isolated. An enterotoxin-negative derivative (25KHO9st) was used for further studies. Using an immunogold-labeling technique, the F17 antigen was characterized as a fimbrial protein. Pure fimbriae with a subunit molecular weight of 20,000 were obtained by homogenization and use of a sucrose gradient. The adhesion of E coli 25KHO9st was mediated by the F17 fimbriae, as both F17 antibodies and F17 protein blocked the adhesion of the strain 25KHO9st. The F17 fimbriae were serologically distinct from K88, K99, F41, and 987P fimbriae and did not agglutinate bovine, ovine, guinea pig, human, or chicken erythrocytes. Peptide fingerprint analysis revealed F17 and F(Y) adhesins to be homologous, if not identical.  相似文献   

Characterisation of Escherichia coli strains associated with canine urinary tract infections   总被引：1，自引：0，他引：1  

B Westerlund  A Pere  T K Korhonen  A K Jarvinen  A Siitonen  P H Williams 《Research in veterinary science》1987,42(3):404-406

Of 33 Escherichia coli strains isolated from canine urinary tract infections, 22 were haemolytic and 27 were classified into O serogroups, the most common being O4, O6, O2 and O83. P-fimbriated strains were haemolytic and belonged mainly to serogroups O4 and O6. Twenty-nine strains possessed type-1 fimbriae but only small numbers possessed S fimbriae, type-1C fimbriae, X adhesins or the aerobactin system. It is postulated that P fimbriae and haemolysin production contribute to bacterial virulence in canine pyelonephritis and cystitis.  相似文献   

Bioenergetic calculation of mercury accumulation in fish     

Pekka Korhonen  Markku Virtanen  Titta Schultz 《Water, air, and soil pollution》1995,80(1-4):901-904

A numerical model was developed for the bioaccumulation of mercury (Hg) in fish. The model is based on the bioenergetic calculation of fish growth, food consumption, respiration, specific dynamic action and waste losses (egestion/excretion) using the program of Hewett and Johnson (1992). Based on the predation and food results obtained, the accumulation of Hg in fish is calculated taking into account the concentrations of methyl mercury (MeHg) in food and water, its intake and accumulation from food and from water, and the removal of Hg from the body. Some species at various levels of food web are considered in the multistep model applications. The model is used to compute the changes of Hg contents in perch (as prey) and pike (as predator) caused by the release of Hg from the bottom sediments when the Kokemäki River in Western Finland was dredged. The model results were not far from the observed results even though the forcing conditions had been described only roughly.  相似文献   

Remote sensing and forest inventories in Nordic countries – roadmap for the future     

Annika Kangas  Rasmus Astrup  Johannes Breidenbach  Jonas Fridman  Terje Gobakken  Kari T. Korhonen 《Scandinavian Journal of Forest Research》2018,33(4):397-412

The Nordic countries have long traditions in forest inventory and remote sensing (RS). In sample-based national forest inventories (NFIs), utilization of aerial photographs started during the 1960s, satellite images during the 1980s, laser scanning during the 2000s, and photogrammetric point clouds during the 2010s. In forest management inventories (FMI), utilization of aerial photos started during the 1940s and laser scanning during the 2000s. However, so far, RS has mostly been used for map production and research rather than for estimation of regional parameters or inference on their accuracy. In recent years, the RS technology has been developing very fast. At the same time, the needs for information are constantly increasing. New technologies have created possibilities for cost-efficient production of accurate, large area forest data sets, which also will change the way forest inventories are done in the future. In this study, we analyse the state-of-the-art both in the NFIs and FMIs in the Nordic countries. We identify the benefits and drawbacks of different RS materials and data acquisition approaches with different user perspectives. Based on the analysis, we identify the needs for further development and emerging research questions. We also discuss alternatives for ownership of the data and cost-sharing between different actors in the field.  相似文献   

Atmospheric Mercury Fluxes in a Southern Boreal Forest and Wetland     

Katriina Kyllönen  Hannele Hakola  Heidi Hellén  Markku Korhonen  Matti Verta 《Water, air, and soil pollution》2012,223(3):1171-1182

Total gaseous mercury (TGM) fluxes from the forest floor and a boreal wetland were measured by a flux chamber technique coupled with an automatic mercury vapour analyser. The fluxes were measured at three sampling sites in southern Finland, 61°14′ N, 25°04′ E in summer 2007, with additionally in situ TGM concentrations in the air at one of the sites and mercury bulk deposition at another. Most of the flux data were collected during the daytime. At one of the sites, diurnal flux behaviour was studied, and a clear cycle with an afternoon maximum and a night minimum was observed. The highest emissions (up to 3.5 ng m⁻² h⁻¹) were observed at the forest floor site having a moss and grass cover. At the wetland and litter-rich forest floor sites, the emissions were below 1 ng m⁻² h⁻¹ and sometimes negative (down to −1.0 ng m⁻² h⁻¹), indicating mercury uptake. The measured average fluxes in August were 0.9 ± 1.1 and 0.2 ± 0.3 ng m⁻² h⁻¹ for the forest floor sites and wetland sites, respectively. The flux data were compared with the mercury bulk deposition, which proved to be of the same magnitude, but opposite in sign. At the mossy forest floor site, the extrapolated TGM emissions were 130% of the Hg deposition in August 2007. Comparison with other studies showed that the fluxes in background areas are relatively uniform, regardless of measurement site location and method used. Airborne TGM remained at the background level during the study, with an average value of 1.3 ± 0.2 ng m⁻³; it frequently showed a diurnal cycle pattern.  相似文献   

The North American P group of Heterobasidion annosum s.l. is widely distributed in Pinus pinea forests of the western coast of central Italy     

L. D&#x;Amico  E. Motta  T. Annesi  M. Scire&#x;  N. Luchi  J. Hantula  K. Korhonen  P. Capretti 《Forest Pathology》2007,37(5):303-320

The distribution of the North American P group of Heterobasidion annosum s.l., recently reported from a Pinus pinea forest in the surroundings of Rome, was studied using mating tests and DNA fingerprinting (mitochondrial DNA, random amplified microsatellite technique and two group‐specific markers). This fungus is present in several forests and small plantations along the Tyrrhenian coast of the Italian peninsula, within an area approximately 100 km long, extending from Fregene in the north to the National Park of Circeo in the south, and 27 km wide including the city of Rome. In pine forests of Castelporziano, Castel Fusano and Anzio, where US troops resided during the Second World War, the North American P group is more frequent than the European P group. The low number of mating alleles in the Italian population of the North American P group supports the hypothesis of its origin from a small number of introductions. The near 100% sexual compatibility between the North American and European P groups, together with inconsistencies in results obtained with different identification methods of these groups, suggests that hybridization between the North American and European P populations occurs occasionally.  相似文献