Prediction of total and rare plant species richness in agricultural landscapes from satellite images and topographic data     

Luoto  Miska  Toivonen  Tuuli  Heikkinen  Risto K. 《Landscape Ecology》2002,17(3):195-217

The diversity of future landscapes might depend on our ability to predict their potential species richness. The predictability of patterns of vascular plant species richness in a Finnish agricultural river landscape was studied using generalized linear modeling, floristic records from fifty-three0.25-km grid squares in the “core” study area, and environmental variables derived from Landsat TM images and a digital elevation model. We built multiple regression models for the total number of plant species and the number of rarities, and validated the accuracy of the derived models with a test set of 52 grid squares. We tentatively extrapolated the models from the core study area to the whole study area of 601 km² and produced species richness probability maps using GIS techniques. The results suggest that the local ‘hotspots’ of total flora (grid squares with > 200species) are mainly found in river valleys, where habitat diversity is high and a semi-open agricultural-forest mosaic occurs. The ‘hotspots’ of rare species (grid squares with > 4 rare species) are also found in river valleys, in sites where extensive semi-natural grasslands and herb-rich deciduous forests occur on steep slopes. We conclude that environmental variables derived from satellite images and topographic data can be used as approximate surrogates of plant species diversity in agricultural landscapes. Modeling of biological diversity based on satellite images and GIS can provide useful information needed in land use planning. However, due to the potential pitfalls in processing satellite imagery and model-building procedures, the results of predictive models should be carefully interpreted. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Occurrence of Gremmeniella abietina damage on Scots pine along a pollution gradient from Monchegorsk nickel smelter to western Lapland     

J. Kaitera  A. Fedorkov  R. Jalkanen  V. Krutov  V. Tsvetkov 《Forest Pathology》1995,25(1):13-23

Gremmeniella abietina damage was studied at stand and tree level on the Kola Peninsula and in northern Finland. At stand level, damage was recorded in four areas in Finland, while only individual damaged trees were found in Russia. According to the results of branch analysis, there was no sign of endemic epidemics in any of the areas. There was a significant negative correlation between the average G. abietina damage and modelled SO₂ deposition and temperature sum along the gradient. The results suggest that G. abietina is distributed all over northern Finland and the Kola Peninsula in natural stands of Scots pine, and that the direct effect of SO₂ deposition from the Monchegorsk nickel smelter on the damage may be minimal.  相似文献   

Foliar nutrient composition in bareroot Pinus sylvestris nursery crops     

Anneli Jalkanen  Risto Rikala 《New Forests》1995,10(3):225-237

We evaluated how the variability of nutrient concentrations affects their suitability as quality attributes. Foliar elements of four batches of three-year-old bareroot Scots pine seedlings, 150 seedlings from each batch, were analyzed. The variability in the concentrations of N, P, and K was small (coefficient of variation in a batch was 11–12), that of Ca and Zn intermediate (CV 19–21), and that of Mg, Mn, Fe, Al, Cu and Na was large (CV 26–35), being close to the variability in morphological attributes. Micronutrients varied more than macronutrients and a larger sample would be needed to estimate these concentrations with the same precision. Correlations between seedling size and nutrient concentrations in needles were small. Positive and negative correlations were found among nutrient concentrations, but not large enough to allow us to predict concentrations with each other. For concentrations of some nutrients the variance within batches was smaller than was found for morphological attributes in both relative and absolute terms, which provides support for batch culling.  相似文献   

Genotypic variation in wood properties and growth traits of <Emphasis Type="Italic">Eucalyptus</Emphasis> hybrid clones in southern China     

Shijun Wu  Jianmin Xu  Guangyou Li  Vuokko Risto  Zhihu Du  Zhaohua Lu  Baoqi Li  Wei Wang 《New Forests》2011,42(1):35-50

Growth traits, wood properties and bark percentage were assessed for 19 hybrid eucalypt clones at three sites in southern China sampled at age 51 months. Analysis of variance showed that there were significant differences in growth traits and wood properties between clones and sites, and that the clone × site interactions were also significant except for basic density. Coefficients of variation ranged from 8.4 to 27.9% for growth traits, 2.7–11.1% for wood properties and 14.0–23.3% for bark percentage. Repeatability ranged from 0.73 to 0.96 for growth traits, 0.32–0.93 for wood properties and 0.77–0.88 for bark percentage. Strong genotypic correlations between the same traits in clones at pairs of sites indicated that the traits were rather stable across sites. The genotypic correlations between growth traits and basic density ranged from −0.67 to 0.43, and generally favorable negative genotypic correlations between growth traits and bark percentage were also found. The correlations between growth traits and Pilodyn pin penetration were positive, ranging from 0.28 to 0.65 and therefore unfavorable as lower wood density will be associated with higher values of Pilodyn pin penetration and improved growth rate. The correlations between traits assessed using non-destructive field methods and wood property assessment results indicated that Pilodyn and Fakopp microsecond timer tools can be confidently used to indirectly select for fiber width and basic density.  相似文献   

Screening for fungal antagonists of seed-borne Fusarium culmorum on wheat using in vivo tests   总被引：1，自引：0，他引：1  

Esa Teperi  Milja Keskinen  Elise Ketoja  Risto Tahvonen 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(3):243-251

A screening system is described for identifying fungal antagonists from soil which are effective in controlling seed-borne Fusarium culmorum on wheat (T. aestivum L.). The procedure comprised three consecutive in vivo tests done under controlled conditions using three different plant growing media. Altogether 1701 fungal isolates from Finnish field soils were screened for biocontrol activity. 210 fungal isolates that had advanced to various stages in the screening system were also included in a field experiment. The isolates that were the most effective in controlling seedling blight under natural conditions belonged to the genus Gliocladium. The screening tests separated Gliocladium spp. rather clearly from the rest of test fungi and thus the overall agreement among the results was good. The assays run under controlled conditions did not efficiently predict which of the Gliocladium isolates would be best in protecting wheat seedlings under field conditions.  相似文献   

Genetic variation of the resin top fungus in Finland as determined by random amplified microsatellites (RAMS)     

J. Hantula  E. Maarit Niemi  J. Kaitera  R. Jalkanen  T. Kurkela 《Forest Pathology》1998,28(6):361-372

The analysis of random amplified microsatellite (RAMS) markers among aecia of the causal agent of the resin top disease (Peridermium pini) on Scots pine (Pinus sylvestris) suggested that the genetic variation between the populations of this rust fungus is low in Finland. The method used allowed the identification of heterozygotic aecia in two loci, where the degree of heterozygosity was, however, low. The RAMS patterns of the Finnish aeciospores, other aeciospores from Thetford, UK and Cronartium flaccidum from Italy were highly similar suggesting that the autoecious and heteroecious forms of these rust fungi would be genetically closely related.  相似文献   

Frost hardiness of nutrient-loaded two-year-old <Emphasis Type="Italic">Picea abies</Emphasis> seedlings in autumn and at the end of freezer storage     

Jaana Luoranen  Markku Lahti  Risto Rikala 《New Forests》2008,35(3):207-220

The effects of nutrient loading (NLOAD) on the frost hardening and dehardening of Picea abies (L.) Karst. seedlings were investigated under nursery conditions. Before NLOAD, second-year container seedlings were either short-day (SD) treated for 3 weeks in July or left for the natural photoperiod (CO). By mid-September, after 5 weeks of NLOAD, the fertilization of three foliar nutrient concentration levels (low = L-SD, medium = M-SD, and high = H-SD) for the SD-treated seedlings and one (medium = M-CO) for the CO-seedlings was completed. The NLOAD resulted in foliar nitrogen concentration 10.6, 16.1, 22.3, and 17.5 g kg⁻¹ for L-SD, M-SD, H-SD and M-CO seedlings, respectively. The NLOAD had no effects on the morphology or dry mass variables of the seedlings, while SD-treatment reduced the dry mass of shoots, but not that of roots. The frost hardiness (FH) of different batches of the seedlings was assessed by the visual scoring of damage in their needles, stems and buds after their controlled exposure to freezing during frost hardening and dehardening. The low nutrient concentration in the SD-treated seedlings (L-SD seedlings) resulted in poor FH, to an even lower extent than that of the M-CO seedlings. The NLOAD did not affect the dehardening of the seedlings at the end of the freezer storage in the following spring.  相似文献   

Meat colour,fatty acid profile and carcass characteristics of Hereford bulls finished on grazed pasture or grass silage-based diets with similar concentrate allowance     

Arto Huuskonen  Susanna Jansson  Markku Honkavaara  Leena Tuomisto  Risto Kauppinen  Erkki Joki-Tokola 《Livestock Science》2010,131(1):125-129

The objective of this study was to determine the impact of grazed grass (PAS bulls) and grass silage-based (UB bulls) diets on muscle colour, intramuscular fatty acid composition and carcass characteristics of Hereford bulls with similar concentrate allowances, ages, growth rates and carcass weights. The carcass fat score of the UB bulls was 14% higher than that of the PAS bulls (P < 0.05). Muscle lightness was 5%, redness 5% and yellowness 8% higher in the UB bulls than in the PAS bulls (P < 0.05). The Longissimus muscle (LM) of the UB bulls contained a higher proportion of 14:1 and 16:0 fatty acids compared to that of the PAS bulls (P < 0.05). In contrast, the LM of the PAS bulls contained a higher proportion of 18:3n-3 fatty acid and 18:2 cis-9 trans-11 CLA compared to that of the UB bulls (P < 0.01). There were no differences in saturated fatty acid, monounsaturated fatty acid or polyunsaturated fatty acid proportions of the LM muscle between treatments.  相似文献   

Conducting sustainability impact assessments of forestry-wood chains: examples of ToSIA applications     

Marcus Lindner  Wendelin Werhahn-Mees  Tommi Suominen  Diana V?tter  Sergey Zudin  Matias Pekkanen  Risto P?ivinen  Martina Roubalova  Petr Kneblik  Franka Brüchert  Erik Valinger  Ludovic Guinard  Stefania Pizzirani 《European Journal of Forest Research》2012,131(1):21-34

Within the EFORWOOD project, new methodological approaches to assess the sustainability impacts of forestry-wood chains (FWC) were developed by using indicators of environmental, social and economic relevance. This paper introduces and discusses the developed approach and the two main products developed in the EFORWOOD project: the Database Client and the Tool for Sustainability Impact Assessment (ToSIA), which hold, calculate and integrate the extensive information and data collected. Sustainability impact assessment (SIA) of FWCs is based on measuring and analysing environmental, economic and social indicators for all of the production processes along the value chain. The adoption of the method varies between applications and depends on the specification of the FWC in the assessment and what questions are studied. ToSIA is very flexible and can apply forest-, product-, industry- and consumer-defined perspectives. Each perspective influences the focus of the analysis and affects system boundaries. ToSIA can assess forest value chains in different geographical regions covering local, regional, national and up to the continental scale. Potential issues and scenarios can be analysed with the tool including, for example, the impacts of different forest policies on the sustainability of an FWC. This paper presents how ToSIA can be applied to solve such diverse problems and underlines this with examples from different case studies. Differences in chain set-up, system boundaries and data requirements are highlighted and experiences with the implementation of the sustainability impact assessment methods are discussed. The EFORWOOD case studies offer valuable reference data for future sustainability assessments.  相似文献   

The time series of flowering and leaf bud burst of boreal trees (1846–2005) support the direct temperature observations of climatic warming     

Tapio Linkosalo  Risto Häkkinen  Juhani Terhivuo  Heikki Tuomenvirta  Pertti Hari 《Agricultural and Forest Meteorology》2009,149(3-4):453-461

The timing of spring phenological events of boreal trees, such as flowering and leaf bud burst, is controlled to a great extent by the ambient air temperature, and these events are already showing an advancement that can be attributed to climatic warming. In this paper we utilised this phenomenon to verify direct observations of climatic warming. We constructed eight phenological time series using observations covering 160 years of the leaf bud burst of two species and of the flowering of six species of native deciduous trees growing in Finland. To eliminate the effect of urbanization on local temperature, we rejected the observations made in densely populated areas. When analyzing the trends in the timing of leaf bud burst and flowering we found an advancement of these phenological events ranging from 3.3 to 11.0 days per century. We then converted the observed phenological trends into temperature trends by using thermal time-type models that link the timing of bud burst and flowering to the temperature conditions during bud development. Warming estimates derived from the phenological trends suggested that the mean spring temperature increase in Finland has been 1.8 °C per century, which is very close to the value of 1.5 °C per century indicated by long-term temperature records.  相似文献