Characteristics of soil seed bank in plantation forest in the rocky mountain region of Beijing, China

We investigated characteristics （scales and composition） of soil seed banks at eight study sites in the rocky mountain region of Beijing by seed identification and germination monitoring. We also surveyed the vegetation communities at the eight study sites to explore the role of soil seed banks in vegetation restoration. The storage capacity of soil seed banks at the eight sites ranked from 766.26 to 2461.92 seeds·m？2. A total of 23 plant species were found in soil seed banks, of which 63–80% of seeds were herbs in various soil layers and 60% of seeds were located in the soil layer at 0–5 cm depth. Biodiversity indices indicated clear differences in species diversity of soil seed banks among different plant communities. The species composition of aboveground vegetation showed low similarity with that based on soil seed banks. In the aboveground plant community, the afforestation tree species showed high importance values. The plant species originating from soil seed banks represented natural regeneration, which also showed relatively high importance values. This study suggests that in the rocky mountain region of Beijing the soil seed banks played a key role in the transformation from pure plantation forest to near-natural forest, promoting natural ecological processes, and the role of the seed banks in vegetation restoration was important to the improvement of ecological restoration methods.

40 Years of Surface Warming in the Northern US Rocky Mountains: Implications for Snowpack Retreat

The northern US Rocky Mountains are experiencing rapid warming. Combined analysis of Ground Temperature (GT) measurements at two high-fidelity boreholes with Surface Air Temperature (SAT) measurements near Helena Montana spanning the past 40 years indicate the northern US Rockies have warmed on average 0.12°C - 0.32°C/decade since 1975, at least a factor of ~5 higher than the predicted 500-year-average. Warming appears to be accelerating, with warming rates since 2013 4 - 7 times higher than the 40 year average. Though uncertainty exists, the most significant GT warming appears to occur at higher elevation. Warming estimates are consistent with modelling predictions, snowpack observations, and stream temperature studies, all suggesting rapid surface temperature change in this region during the past ~40 years. The analysis indicates GT warming measured at remote borehole sites is slightly lower than regional SAT measurements collected near urban environments. We associate the discrepancy between GT/SAT measurements to both anthropogenic effects (urban development) that increase warming at the nearest SAT measurement station and a 14-year period of anomalously low snowfall that reduces surface insulation and GT warming. Using a derived average forty-year surface warming rate of 0.22°C/ decade and regional temperature-elevation trends, we calculate that the elevation of the winter freeze line during the three coldest months of the year (December, January, and February) in the northern US Rocky Mountains is retreating upward, on average, 33 m/decade. This implies a 21% reduction in freeze-line area since 1974. If this trend continues, we estimate that within the next 40 years (by 2060), the total area where ground freeze occurs during the three coldest months of the year will be ~60% of 1974 values. Since GT measurements indicate accelerated warming, this may be an underestimate. The analysis has important implications for the snowpack-water budget for Montana and the northern US Rocky Mountains.

Regional- to local-scale controls on waterfalls in Rocky Mountain National Park,Colorado

Previous work on the eastern side of Rocky Mountain National Park(RMNP),Colorado indicated correlations among waterfall location,waterfall morphology,and the characteristics of bedrock joints.Characteristics of waterfalls on the western side of the national park do not correlate as strongly with joint geometry.Longitudinal river profiles on the western side are less concave and waterfalls account for a greater proportion of the total elevation loss.We interpret these differences to result from more widely spaced joints,lithological differences,and complex glacial history.These results demonstrate that waterfall shape and typology may change due to both local and regional controls operating in a mountain region.Both regions had alpine valley glaciers,but continued landscape evolution via fluvial erosion has developed waterfalls with diverse locations and morphologies that reflect the influences of glacial deposits,bedrock erosional resistance,and joint geometry.

Potential influence of wildfire in modulating climate-induced forest redistribution in a central Rocky Mountain landscape

Introduction:Climate change is expected to impose significant tension on the geographic distribution of tree species.Yet,tree species range shifts may be delayed by their long life spans,capacity to withstand long periods of physiological stress,and dispersal limitations.Wildfire could theoretically break this biological inertia by killing forest canopies and facilitating species redistribution under changing climate.We investigated the capacity of wildfire to modulate climate-induced tree redistribution across a montane landscape in the central Rocky Mountains under three climate scenarios(contemporary and two warmer future climates)and three wildfire scenarios(representing historical,suppressed,and future fire regimes).Methods:Distributions of four common tree species were projected over 90 years by pairing a climate niche model with a forest landscape simulation model that simulates species dispersal,establishment,and mortality under alternative disturbance regimes and climate scenarios.Results:Three species(Douglas-fir,lodgepole pine,subalpine fir)declined in abundance over time,due to climate-driven contraction in area suitable for establishment,while one species(ponderosa pine)was unable to exploit climate-driven expansion of area suitable for establishment.Increased fire frequency accelerated declines in area occupied by Douglas-fir,lodgepole pine,and subalpine fir,and it maintained local abundance but not range expansion of ponderosa pine.Conclusions:Wildfire may play a larger role in eliminating these conifer species along trailing edges of their distributions than facilitating establishment along leading edges,in part due to dispersal limitations and interspecific competition,and future populations may increasingly depend on persistence in locations unfavorable for their establishment.

Structural Interpretation and Restoration of Rocky Mountain Brazeau Zone

The Rocky Mountain Foothills lie along the eastern margin of the Rocky Mountain fold-thrust belt. The area has been the focus of extensive research aimed at locating oil and gas fields with the potential to be used as CO2 storage traps. In this study, we use a seismic line from the Ca- nadian Rockies to interpret the geologic structures along a cross-section parallel to the tectonic transport direction. We then compare our results with those of previous studies. The section was restored using the MOVE software （manufactured by Midland Valley Exploration Ltd.）. The pri- mary objectives of this work are： （1） to conduct a stratigraphic and structural interpretation of a 2D seismic profile; and （2） to conduct a cross-sectional restoration of the structures in order to validate the seismic interpretation in terms of CO2 storage candidates. Additional data sources include maps of the surface geology, which show that the age of horizons decrease from west to east, and strati- graphic and structural profiles derived from well logs. The results of our structural restoration indi- cate a detachment fault between the foreland and hinterland. This fault is responsible for the cutting and subsequent upwards and eastwards movement of a stratum located between the basement and the Late Devonian formation. Large thrust faults are responsible for the deformation of strata （through both folding and faulting） in the foreland basin. As a result of continuous eastward tectonic stress, the strata from Jurassic have deformed, forming a duplex system in the middle of the section and resulting in the uplift of the upper part of the section. Following surface erosion, this uplifted area became exposed during the Tertiary Period. The high shortening rate （53%） detected through structural restoration is consistent with the thin-skinned tectonic model.

DYNAMIC INFLUENCE OF QINGHAI-XIZANG PLATEAU AND ROCKY MOUNTAINS ON THE LEE CYCLONES

Using the operational model(B model)of Beijing Meteorological Center,we do some of numerical experi- ments of crossing and rounding mountains in all velocity adjustment scheme,and study dynamic effect of Qinghai-Xizang Plateau and Rocky Mountains on lee cyclones.The results show that due to air flow round the Qinghai-Xizang Plateau,divergence is distributed in the shape of confluence which matches cyclogenesis area and cyclonic track in East Asia.In the downstream of the Qinghai-Xizang Plateau,convergence in the upper troposphere restrains cyclone development in the east of China mainland.In North America, air flow primarily crosses over Rocky Mountains.Air is adiabatically cooled when it flows upward in the west flank of Rocky Mountains,while air is warmed when it flows downward in the lee side.The fact is important for the lee cyclogenesis and the lee frontogenesis of Rocky Mountains.Air flow crossing over Rocky Mountains is also the main cause for forming dryline in the mid-west of United States.

Analyzing Anomalous Topographic Map Drainage System and Landform Evidence as a Glacial History Paradigm Problem: A Literature Review

While not usually stated, detailed topographic maps show well-mapped anomalous drainage system and other erosional landform evidence the accepted North American Cenozoic geologic and glacial history paradigm (accepted paradigm) does not permit geomorphologists to satisfactorily explain. A new and fundamentally different paradigm able to explain the drainage system and other erosional landform evidence has recently emerged, but requires what the accepted paradigm considers to be the preglacial (and probably mid-Cenozoic) Bell River drainage system to have formed on a melting continental ice sheet’s floor. The new paradigm’s melting ice sheet had previously eroded bedrock underneath it and caused crustal warping that raised continental regions and mountain ranges so as to create and occupy a deep “hole” while massive and prolonged meltwater floods flowed across rising continental regions and mountain ranges to the south. The new paradigm leads to a completely different middle Cenozoic geologic and glacial history than the accepted paradigm describes and the two paradigms are analyzed according to good science expectations such as using evidence anyone can see, applying common sense logic during each research step, producing consistent results, and simplicity of paradigm generated explanations. The new paradigm uses topographic map evidence anyone can see, appears to use common sense logic during each research step, and produces remarkably consistent results leading to a simpler Cenozoic northern Missouri River drainage basin region geologic and glacial history than what the accepted paradigm describes. Further work is needed to test the new paradigm’s ability to explain drainage system and erosional landform evidence in other geographic regions such as in the Ohio River drainage basin.