88 research outputs found
PENINGKATAN KEMAMPUAN KOMUNIKASI DAN DISPOSISI MATEMATIS SISWA SMP MELALUI MODEL PEMBELAJARAN DEEPER LEARNING CYCLE (DELC).
Penelitian ini bertujuan untuk mengkaji peningkatan kemampuan komunikasi dan disposisi matematis siswa SMP melalui model pembelajaran Deeper Learning Cycle (DELC). Desain penelitian yang digunakan adalah kuasi eksperimen. Populasi dalam penelitian ini adalah seluruh siswa kelas VIII di salah satu SMP Negeri di Kabupaten Bandung, dengan mengambil dua kelas sebagai sampel menggunakan teknik purposive sampling dari 10 kelas yang tersedia. Adapun sampelnya, yaitu sebanyak 35 siswa kelas eksperimen dan 35 siswa kelas kontrol. Kelas eksperimen memperoleh pembelajaran dengan mengikuti model Deeper Learning Cycle (DELC) dan kelas kontrol mengikuti model ekspositori. instrumen yang digunakan dalam penelitian ini adalah pretes dan postes untuk kemampuan komunikasi dan disposisi matematis siswa. Untuk melihat peningkatan kemampuan komunikasi dan disposisi matematis siswa antara kelas eksperimen dan kelas kontrol, digunakan independent sample t-test, dan Mann-Whitney dengan taraf signifikansi 0,05, setelah prasyarat pengujian terpenuhi. Hasil penelitian dianalisis dengan menggunakan Microsoft Excel 2007 dan SPSS versi 22,sedangkan analisis data kualitatif dilakukan secara deskriptif. Hasil penelitian menunjukkan bahwa pencapaian dan peningkatan kemampuan komunikasi matematis serta pencapaian disposisi matematis siswa yang mengikuti pembelajaran model Deeper Learning Cycle (DELC) lebih baik dari kelas kontrol. Terdapat asosiasi yang sedang antara pencapaian postes kemampuan komunikasi dan disposisi matematis siswa. Analisis data skala sikap disposisi matematis menunjukkan bahwa secara umum siswa memiliki respon positif dengan mengikuti model pembelajaran Deeper Learning Cycle (DELC). ---------- This study aims to assess the improvement of communication skill and students’ mathematical disposition through learning model of Deeper Learning Cycle (DELC). The study design used in the study is a quasi-experiment. The population in the study is all students in grade 8 at one junior high school in Bandung district, by taking two classes as the sample using purposive sampling technique of the 10 classes. As for the sample as many as 35 students of experimental class and 35 students of control class. Experimental class deserve the learning by following the model of Deeper Learning Cycle, and control class following the model of expository. The instrument used in the study is pre-test and post-test for students’ communication skill and mathematical disposition. To see the improvement of students’ communication skill and mathematical disposition among experimental class and control class, it is used independent sample t-test and Mann Whitney with significance level 0.05, after testing pre-Requisite are met. The result of the study is analyzed using Microsoft Excel 2007, and SPSS 22 version, meanwhile qualitative data analysis is conducted descriptively. The result of the study shows that the Achievement and the improvement of students’ communication of mathematical skill and the achievement of student’s mathematical disposition that follow the learning model of Deeper Learning Cycle (DELC) is better than control class. There is a moderate association between students’ achievement of the post-test communication skill and students’ mathematical disposition. Analysis of scale data for students who has Deeper Learning Cycle (DELC) has a positive response
Spatial variation of surface soil carbon in a boreal forest – the role of historical fires, contemporary vegetation, and hydro-topography
Knowledge about the spatial variation of boreal forest soil carbon (C) stocks is limited, but crucial for establishing management practices that prevent losses of soil C. Here, we quantified the surface soil C stocks across small spatial scales, and aim to contribute to an improved understanding of the drivers involved in boreal forest soil C accumulation. Our study is based on C analyses of 192 soil cores, positioned and recorded systematically within a forest area of 11 ha. The study area is a south-central Norwegian boreal forest landscape, where the fire history for the past 650 years has been reconstructed. Soil C stocks ranged from 1.3 to 96.7 kg m−2 and were related to fire frequency, ecosystem productivity, vegetation attributes, and hydro-topography. Soil C stocks increased with soil nitrogen concentration, soil water content, Sphagnum- and litter-dominated forest floor vegetation, and proportion of silt in the mineral soil, and decreased with fire frequency in site 1, feathermoss- and lichen-dominated forest floor vegetation and increasing slope. Our results emphasize that boreal forest surface soil C stocks are highly variable in size across fine spatial scales, shaped by an interplay between historical forest fires, ecosystem productivity, forest floor vegetation, and hydro-topography.Spatial variation of surface soil carbon in a boreal forest – the role of historical fires, contemporary vegetation, and hydro-topographyacceptedVersio
Trends and patterns in annually burned forest areas and fire weather across the European boreal zone in the 20th and early 21st centuries
Fire remains one of the main natural disturbance factors in the European boreal zone and understanding climatic forcing on fire activity is important for projecting effects of climate change on ecosystem services in this region. We analyzed records of annually burned areas in 16 administrative regions of the European boreal zone (countries or administrative units within countries) and fire weather variability to test for their spatio-temporal patterns over the 1901-2017 period.Over the 1992-2017 period, the region exhibited large variability in forest fire activity with the fire cycles varying from similar to 1600 (St. Petersburg region) to similar to 37000 years (Finland). The clustering of administrative units in respect to their burned area, suggested the presence of sub-regions with synchronous annual variability in burned areas. Large fire years (LFYs) in each of the clusters were associated with the development of the high pressure cell over or in immediate proximity of the regions in question in July, indicating climatic forcing of LFYs. Contingency analysis indicated that there was no long-term trend in the synchrony of LFYs observed simultaneously in several administrative units. We documented a trend towards higher values of Monthly Drought Code (MDC) for the months of April and May in the western (April) and northern (April and May) sections. The significant positive correlation between biome-wide fire activity index and June SNAO (Summer North Atlantic Oscillation) (r = 0.53) pointed to the importance of large-scale atmospheric circulation, in particular the summer European blocking pattern, in controlling forest fires across EBZ. The forest fire activity of the European boreal zone remains strongly connected to the annual climate variability. Higher frequency of strongly positive SNAO states in the future will likely synchronize years with a large area burned across the European boreal zone
Oppdatering av kunnskapsgrunnlag for klimatiltak i skog: Gjennomgang av 11 utvalgte tiltak i bestandsskogbruket
På oppdrag fra Miljødirektoratet og Landbruksdirektoratet har vi gått gjennom kunnskapsstatus på 11 ulike tiltak utvalgt av direktoratene. Alle tiltakene ligger innenfor det tradisjonelle bestandsskogbruket. Tiltakene er vurdert ut fra hvordan de kan øke skogens netto CO2-opptak (karbonlagring), men for noen tiltak også betydning for andre klimagasser og for biogeofysiske effekter som albedo. Utvalget er ikke uttømmende, og også andre tiltak gjennom omløpet vil ha effekt på skogens CO2-opptak. Potensielle substitusjonseffekter gjennom tilgang på mer tømmer eller tømmer med høyere kvalitet er ikke inkludert. Klimatilpasning har vært med i vurderingen av alle tiltak. Det er korte omtaler av tiltakenes effekter på naturmangfold.Oppdatering av kunnskapsgrunnlag for klimatiltak i skog: Gjennomgang av 11 utvalgte tiltak i bestandsskogbruketpublishedVersio
Temporal, spatial, and structural patterns of adult trembling aspen and white spruce mortality in Quebec's boreal forest
Temporal, spatial, and structural patterns of adult trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) mortality were studied in intact 150-year-old stands in the southwestern boreal forest of Quebec. For both species, mortality decreases (number of dead trees/total number of trees) with distance from the lake edge until 100-150 m, from which point it slightly increases. Strong peaks in mortality were found for 40- to 60-year-old aspen mainly between 1974 and 1992. Such mortality in relatively young aspen is likely related to competition for light from the dominant canopy trees. Also, the recruitment of this young aspen cohort is presumably the result of a stand breakup that occurred when the initial aspen-dominated stand was between 90 and 110 years old. For spruce, strong peaks in mortality were found in 110- to 150-year-old trees and they occurred mainly after 1980. No clear explanation could be found for these peaks, but we suggest that they may be related to senescence or weakening of the trees following the last spruce budworm outbreak. Suppressed and codominant aspen had a much higher mortality ratio than spruce in the same height class, while more surprisingly, no difference in mortality rate was found between dominant trees of the two species. Most spruce trees were found as standing dead, which leads us to reject the hypothesis that windthrow is an important cause of mortality for spruce in our forests
Do larger snags stand longer?—snag longevity in mixed conifer–hardwood forests in Hokkaido, Japan
Hogstaktivitet og artsmangfold i boreal skog. Fra studieområdene Gartland (Grong), Oppkuven (Ringerike) og Heimseteråsen (Sigdal)
publishedVersio
Hogstaktivitet og artsmangfold i boreal skog. Fra studieområdene Gartland (Grong), Oppkuven (Ringerike) og Heimseteråsen (Sigdal)
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