scholarly journals The Paleoecological Record of 6 ka BP Climate in the Canadian Prairie Provinces

2007 ◽  
Vol 49 (1) ◽  
pp. 81-98 ◽  
Author(s):  
Robert E. Vance ◽  
Alwynne B. Beaudoin ◽  
Brian H. Luckman
Keyword(s):  
Boreal Forest ◽  
Forest Fires ◽  
Pinus Banksiana ◽  
Summer Precipitation ◽  
Circulation Pattern ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Canadian Prairie ◽  
Temperature And Precipitation ◽  
Prairie Provinces

ABSTRACTSynthesis of available paleoecological studies in the Prairie provinces of Canada indicates that although the peak in postglacial aridity that characterized early Holocene climate of the western foothills and plains had passed, conditions remained warmer and drier than present throughout the region ca. 6000 yr BP Compared to today, treeline elevations were higher and alpine glaciers were reduced in size in the Rocky Mountains, lake levels were lower over much of the Interior Plains, and the grassland and boreal forest ecozones extended north of their present positions. Forest fires were more prevalent ca. 6000 yr BP than they are today, aiding westward migration of jack pine (Pinus banksiana) through the boreal forest and increasing the area occupied by grassland in boreal and montane forest regions. Attempts to quantify the magnitude of 6 ka temperature and precipitation differences have produced variable results, but suggest that mean annual temperature was 0.50°C to 1.50°C higher than today (summer temperature may have been up to 3°C higher) and mean annual precipitation was reduced by 65 mm (or summer precipitation was reduced by 50 mm), compared to present. The nature and scale of these changes suggests that a vigorous zonal atmospheric circulation pattern, similar to that of the 1930s but shifted northward, prevailed at 6 ka.

scholarly journals Temperature and Precipitation Drive Elevational Patterns of Microbial Beta Diversity in Alpine Grasslands

2021 ◽  
Author(s):  
Xiaoqin Yang ◽  
Yue Li ◽  
Bin Niu ◽  
Qiuyu Chen ◽  
Yilun Hu ◽  
...  
Keyword(s):  
Species Richness ◽  
Tibetan Plateau ◽  
Community Composition ◽  
Beta Diversity ◽  
Microbial Community Composition ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Temperature And Precipitation

Abstract Understanding the mechanisms underlying biodiversity patterns is a central issue in ecology, while how temperature and precipitation jointly control the elevational patterns of microbes is understudied. Here, we studied the effects of temperature, precipitation and their interactions on the alpha and beta diversity of soil archaea and bacteria in alpine grasslands along an elevational gradient of 4,300-5,200 m on the Tibetan Plateau. Alpha diversity was examined on the basis of species richness and evenness, and beta diversity was quantified with the recently developed metric of local contributions to beta diversity (LCBD). Typical alpine steppe and meadow ecosystems were distributed below and above 4,850 m, respectively, which was consistent with the two main constraints of mean annual temperature (MAT) and mean annual precipitation (MAP). Species richness and evenness showed decreasing elevational patterns in archaea and nonsignificant or U-shaped patterns in bacteria. The LCBD of both groups exhibited significant U-shaped elevational patterns, with the lowest values occurring at 4,800 m. For the three diversity metrics, soil pH was the primary explanatory variable in archaea, explaining over 20.1% of the observed variation, whereas vegetation richness, total nitrogen and the K/Al ratio presented the strongest effects on bacteria, with relative importance values of 16.1%, 12.5% and 11.6%, respectively. For the microbial community composition of both archaea and bacteria, the moisture index showed the dominant effect, explaining 17.6% of the observed variation, followed by MAT and MAP. Taken together, temperature and precipitation exerted considerable indirect effects on microbial richness and evenness through local environmental and energy supply-related variables, such as vegetation richness, whereas temperature exerted a larger direct influence on LCBD and the community composition. Our findings highlighted the profound influence of temperature and precipitation interactions on microbial beta diversity in alpine grasslands on the Tibetan Plateau.

The perennial Juncus of section Poiophylli in the Canadian prairie provinces

1987 ◽  
Vol 65 (4) ◽  
pp. 750-760 ◽  
Author(s):  
P. M. Catling ◽  
K. W. Spicer
Keyword(s):  
Boreal Forest ◽  
Diagnostic Value ◽  
Canadian Prairie ◽  
Distribution Maps ◽  
Forest Region ◽  
Anther Length ◽  
Southern Alberta ◽  
The Status ◽  
Juncus Gerardii ◽  
Prairie Provinces

Specimens of the perennial Juncus of section Poiophylli in major Canadian herbaria were examined to clarify the status of the group in the prairie provinces and to evaluate diagnostic characters. Six taxa are recognized. Of these, Juncus interior, which occurs in the prairie region of southern Manitoba, southern Saskatchewan, and southern Alberta, has been largely overlooked. Juncus confusus, frequently confused with Juncus tenuis, is confined to southwestern Saskatchewan and southern Alberta. Juncus dudleyi is widespread and common throughout the three provinces, whereas Juncus vaseyi is widespread but clearly less common in the prairie region than in the more northerly boreal forest areas. Juncus tenuis, also found mostly in the boreal forest region, is apparently frequent only in central Saskatchewan and is rare elsewhere. Juncus compressus is recently adventive in southern Manitoba. Reports of Juncus gerardii are discounted and J. oronensis is considered to be a rare hybrid. The diagnostic value of characteristics of the leaf auricle is affirmed through correlation with other distinctive characters such as the shape of the bracteole apex and bracteole length and to a lesser extent with anther length and seed length. Although seed lengths differ between J. dudleyi and J. interior, there is sufficient overlap in the prairie provinces to make this character unreliable for identification. Other taxonomic characters are discussed and an illustrated key and distribution maps are included.

The changing disturbance regime of the boreal forest of the Canadian Prairie Provinces

2003 ◽  
Vol 79 (3) ◽  
pp. 502-516 ◽  
Author(s):  
K P Timoney
Keyword(s):  
Boreal Forest ◽  
Exotic Species ◽  
Deciduous Forest ◽  
Human Impacts ◽  
Coniferous Forest ◽  
Groundwater Depletion ◽  
Fragmented Landscape ◽  
Canadian Prairie ◽  
Boreal Ecosystem ◽  
Prairie Provinces

The subhumid boreal forest of western Canada is different today from what it was 25 years ago. Before the 1950s, the main human impacts on this forest were agricultural expansion, escaped settlement fires, and high-grade logging. The latter half of the 20th Century saw increased human stresses placed on the ecosystems, against a background of insect outbreaks and high forest fire activity. In the Prairie provinces, current annual area burned is greater and more variable than it was in the 1970s. Over the past 25 years, the area disturbed by insects (primarily forest tent caterpillar) and disease has declined, but both the area and timber volume logged have risen. The boreal forest (particularly its southern half) is being converted to a fragmented landscape dominated by young aspen, shrub, grass, plantations, exotic species, industrial infrastructure, and agricultural fields. The current disturbance level has increased to the point that forest land and volume losses now exceed forest accruals in some regions; average forest age and biomass have been declining since about 1970. Relative to past decades, the present subhumid boreal forest region of Canada is warmer, and more fragmented and dissected; it supports less old growth, less old white spruce, and more young aspen and recently disturbed areas; it has simplified and truncated age-class structures; and it has a greater prevalence of non-native plants. Future stresses may include in situ tar sands development, groundwater depletion or degradation, and water diversions. Should present trends continue, declining forest productivity and predictability, and spread of exotic species are likely, as is replacement of coniferous forest by deciduous forest in some regions. Stressed aquatic systems may undergo major changes in biotic composition, productivity, and physical characteristics. Without a rapid decrease in the rate of disturbances, the establishment of a more complete protected areas network, and the adoption of ecosystem-centred management, the subhumid boreal ecosystem will continue to be degraded. Key words: climate, defoliation, ecosystem, fire, logging, perturbation, petroleum, vegetation

scholarly journals DO LATITUDE, ELEVATION, TEMPERATURE, AND PRECIPITATION INFLUENCE BODY AND CLUTCH SIZES OF FEMALE COMMON FIVE-LINED SKINKS, PLESTIODON FASCIATUS (LINNAEUS, 1758)?

2020 ◽  
pp. 32-41
Author(s):  
Jake S. Morrissey ◽  
Brandon Barr ◽  
Andrew E. Austin ◽  
Lauren R. Babcock ◽  
Robert Powell
Keyword(s):  
Body Size ◽  
Mean Annual Precipitation ◽  
Eastern North America ◽  
Mean Annual Temperature ◽  
Negatively Associated ◽  
The North ◽  
Female Body Size ◽  
Temperature And Precipitation ◽  
Plestiodon Fasciatus ◽  
Positive Effect

Common Five-lined Skinks (Plestiodon fasciatus) have an extensive distribution that includes much of eastern North America. We examined 490 female specimens (274 with putative clutch sizes) from throughout the range to see if latitude, elevation, mean annual temperature, and/or mean annual precipitation affected body or clutch sizes. We predicted that larger females would produce larger clutches, latitude and elevation would negatively affect both body and clutch sizes, and that temperature and precipitation would exert a positive effect. Our results did not consistently support those predictions. Body size was positively associated with latitude, negatively associated with temperature, and not associated with elevation or precipitation. Clutch size was not related to female body size, but in most instances was positively associated with temperature and precipitation but negatively associated with elevation and latitude. Effectively K-selected in the North and r-selected in the South, body and clutch sizes in this species appear to be responding to different select.

scholarly journals Growth characteristics of natural and planted Dahurian larch in northeast China

2017 ◽  
Author(s):  
Bingrui Jia ◽  
Guangsheng Zhou
Keyword(s):  
Boreal Forest ◽  
Northeast China ◽  
Management Practices ◽  
Forest Growth ◽  
Larix Gmelinii ◽  
Future Climate Change ◽  
Stand Age ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Dahurian Larch

Abstract. Dahurian larch (Larix gmelinii Rupr.) is the dominant species in both natural and planted forests in northeast China, which situated in the southernmost part of the global boreal forest biome and undergoing the greatest climatically induced changes. Published studies (1965–2015) on tree aboveground growth of Larix gmelinii forests in northeast China were collected in this study, critically reviewed, and a comprehensive growth dataset was developed from 123 sites, which distributed between 40.85° N and 53.47° N in latitude, between 118.20° E and 133.70° E in longitude, between 130 m and 1260 m in altitude. The dataset was composed of 776 entries, including growth data (mean tree height, mean DBH, mean tree volume and/or stand volume) and the associated information, i.e., geographical location (latitude, longitude, altitude, aspect and slope), climate (mean annual temperature (MAT) and mean annual precipitation (MAP)), stand description (origin, stand age, stand density and canopy density), and sample regime (observing year, plot area and number). It would provide quantitative references for plantation management practices and boreal forest growth prediction under future climate change. The DOI for the data is https://doi.org/10.1594/PANGAEA.880984.

scholarly journals The use of Australian bioregions as spatial units of analysis to explore relationships between climate and songbird diversity

2011 ◽  
Vol 17 (4) ◽  
pp. 354 ◽  
Author(s):  
G J Williamson ◽  
L Christidis ◽  
J Norman ◽  
B W Brook ◽  
B Mackey ◽  
...  
Keyword(s):  
Statistical Approach ◽  
Biological Data ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Wet Season ◽  
Spatial Unit ◽  
Temperature And Precipitation ◽  
Units Of Analysis ◽  
Species Area ◽  
Increasing Temperature

Biogeographers often investigate patterns of biodiversity at continental and global scales, using existing data georeferenced to a lattice of cells of latitude and longitude. Problems can arise with this approach when the available biological data are insufficient to adequately sample each cell and the cells are environmentally heterogeneous. An alternative, though less-often employed, approach is to use bioregions (defined as areas with distinctive biophysical environmental characteristics) as the basic sampling unit and to statistically control for unequal areas of regions. Here we applied this latter approach with the Interim Biogeographical Regionalisation of Australia (IBRA) to analyse continental patterns of songbird species richness in relation to mean annual precipitation, mean annual temperature, and mean wet season temperature, which are all predicted to substantially change given anthropogenic climate change. We used the Birds Australia database that has a large sample (>1,560,000) of distribution records covering Australia. For each of the 85 IBRAs, we determined the total number of songbird species and standardized these richness values accounting for the species-area effect by including the log of bioregion area as a covariate in the statistical models. Our analysis of standardized bioregion songbirds richness showed that the best supported model, based on information theory statistics included an interaction of mean annual temperature and precipitation (48.6% deviance explained). The fitted model showed declining richness with increasing temperature and declining precipitation, signalling that future climates may result in regional declines in songbird abundance. We suggest our simple empirical-statistical approach, using bioregions as the spatial unit, has promise for continental and global impact assessment of diversity changes and for conservation planning

scholarly journals Additive model of aboveground biomass of larch single-trees related to age, Dbh and height, sensitive to temperature and precipitation in Eurasia

2020 ◽  
Vol 24 (10) ◽  
pp. 1759-1766
Author(s):  
Vladimir А. Usoltsev ◽  
Seyed Omid Reza Shobairi ◽  
Anna. A. Osmirko ◽  
Ivan. S. Tsepordey ◽  
Viktor. P. Chasovskikh
Keyword(s):  
Regression Models ◽  
Forest Cover ◽  
Additive Model ◽  
Component Composition ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Tree Biomass ◽  
Temperature And Precipitation ◽  
Additive Component ◽  
The Mean

The first attempt of modeling changes in the aboveground additive component composition of larch (genus Larix spp.) tree biomass, according to the Trans-Eurasian hydrothermal gradients of Eurasia on the database compiled for the structure of harvest biomass in a number of 510 sample trees is fulfilled. The adequacy of the obtained regularities is determined by the level of variability 87-99 % explained by the proposed regression models. For the central territory of European Russia, characterized by the mean annual temperature of January -10 °C and the mean annual precipitation of 400 mm, the increase in temperature by 1°C at the constant level of precipitation causes on Larix spp. trees of the equal age and sizes, the decrease in the aboveground, stem, needle and branches by 0.4, 0.3, 1.4 и 1.3 %, respectively. For the same region, in equal-sized trees, the increase in precipitation by 100 mm at a constant annual temperature in January causes the decrease of the aboveground and stem biomass by 1.2 and 1.7%, respectively, and the increase of needle and branches biomass by 4.0 and 6.0%, respectively. The development of such models for the main forest-forming species of Eurasia will make it possible to predict changes in the productivity of the forest cover of Eurasia in connection with climate change. Keywords: larch trees, genus Larix spp., tree biomass, allometric models

scholarly journals Growth characteristics of natural and planted Dahurian larch in northeast China

2018 ◽  
Vol 10 (2) ◽  
pp. 893-898
Author(s):  
Bingrui Jia ◽  
Guangsheng Zhou
Keyword(s):  
Boreal Forest ◽  
Northeast China ◽  
Forest Growth ◽  
Future Climate Change ◽  
Stand Age ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Dahurian Larch ◽  
Growth Data ◽  
Data Set

Abstract. Dahurian larch (Larix gmelinii Rupr.) is the dominant species in both natural and planted forests in northeast China, which is situated in the southernmost part of the global boreal forest biome and is undergoing great climatically induced changes. Published studies (1965–2015) on tree above-ground growth of Dahurian larch forests in northeast China were collected in this study and critically reviewed, and a comprehensive growth data set was developed from 122 sites, which are distributed between 40.85 and 53.47∘ N in latitude, between 118.20 and 133.70∘ E in longitude and between 130 and 1260 m in altitude. The data set is composed of 743 entries and includes growth data (mean tree height, mean diameter at breast height (DBH), mean tree volume and/or stand volume) and associated information, i.e., geographical location (latitude, longitude, altitude, aspect and slope), climate (mean annual temperature (MAT) and mean annual precipitation (MAP)), stand description (origin, stand age, stand density and canopy density) and sample regime (observation year, plot area and plot number). It provides a quantitative reference for plantation management practices and boreal forest growth prediction under future climate change. The data set is freely available for noncommercial scientific applications, and the DOI for the data is https://doi.org/10.1594/PANGAEA.880984.

scholarly journals Biological and extrinsic correlates of extinction risk in Chinese lizards

2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Species Traits ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Specialization ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Small Range ◽  
Extrinsic Factors

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.

Statistical spring wheat yield forecasting for the Canadian prairie provinces

2009 ◽  
Vol 149 (6-7) ◽  
pp. 1022-1031 ◽  
Author(s):  
Budong Qian ◽  
Reinder De Jong ◽  
Richard Warren ◽  
Aston Chipanshi ◽  
Harvey Hill
Keyword(s):  
Spring Wheat ◽  
Wheat Yield ◽  
Canadian Prairie ◽  
Yield Forecasting ◽  
Prairie Provinces
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