The tree line is a climatic boundary, however its ability to respond to changing climate seems to be constrained by the spatial distribution of trees at the leading edge; compared to abrupt or krummholz tree lines, diffuse tree lines are moving upslope much more readily in response to recent anthropogenic warming. Here we report on the micrometeorological processes that result from the diffuse leading edge of a moving tree line on Pikes Peak, Colorado, USA, and on the impacts these processes have on tree temperatures. We focus on the layering and movement of air in the lower 10m of the atmosphere including the height of the displacement of the zero velocity plane. Our experimental design consisted of 300m upslope transects through the tree line into the alpine tundra where we measured: (1) height of the zero plane displacement using handheld anemometers, (2) temperature of 10cm tall seedlings, 3-5m tall trees, and tundra grasses using an IR camera, (3) temperature and relative humidity at 2.5cm an 2m using Kestrel hand held weather stations, (4) the vertical atmospheric profiles using 10m towers equipped with 8 anemometers at 5 different elevations, (5) vertical movement of air using a bubble-blowing machine. Our results show that (1) the zero plane height decreased exponentially with increasing elevation (R2=0.432, N=57, p<0.0005) from approximately 25cm within the tree line to 2.5cm in the tundra above. The spatial variability of the zero plane height also decreased with elevation. (2) The temperature of small seedlings was (3) closely coupled to the ground vegetation (paired t-test t= 2.213, df=10, p=0.051),but seedlings were on average 3.88°C warmer than trees (paired t-test t= 5.808, df=10, p<0.0005), and trees were 6.1°C colder that the tundra (paired t-test t= 6.617, df=10, p<0.0005). (3) Compared to the air at 2m, the air layer at 2cm had higher temperature (+2.5°C, paired t-test t= 7.205, df=19, p<0.0005), and higher relative humidity higher (+29%, paired t-test t= 9.657, df=19, p<0.0005). (4) The vertical wind profile had a simple and smooth slow down to the zero plane at 2.5cm in the alpine tundra. However the profile was complex in all locations where trees were present: It showed an initial slow down to a very low speed at 3-4m, increase in velocity at 2m, and final slow down to the zero plane at 25cm. Qualitative and quantitative analysis of bubble movement (5) showed that the upper boundary layer was turbulent.
Research about drivers of revenue growth or other firm-specific metrics has been studied, but no research has focused on the impact of capital investment as the primary driver of revenue growth. In this paper, we test the hypothesis, “capital investment positively affects revenue growth, and affects young sectors to a greater extent than mature sectors.” We use cross sectional time series GLS for both sectors and find evidence to partially support the claim. We find that there is positive correlation between capital investment and revenue growth for the S&P 500 Materials sector whereas capital investment is not a significant predictor of revenue growth for the S&P 500 Information Technology sector.
This paper addresses intentionally teaching grit to high school students through the use of goal setting and other strategies. Based on the research by Angela Duckworth and Dr. Carol S. Dweck, Ph. D., teachers can implement multi-level goal setting and goal implementation scaffolding to encourage a growth mindset and develop grit in students.
This paper explores the relationship between stock markets and economic growth through investment in developing countries. Stock markets are an important financial instrument for countries to consider when determining the structure of capital allocation in their economy. This study utilizes panel data for 17 countries from 1998 through 2011. An ordinary least squares regression with binary variables is used to capture country specific effects across time. Results suggest that stock markets positively influence economic growth. This is consistent with much of the current literature, which shows stock markets to be an important determinate of economic growth both theoretically and empirically. Understanding the impact of stock markets on economic growth in developing countries can help with policy implications that will continue growth.