scholarly journals Recent Trends in Greenhouse Gases Levels in the Soils of the Coconino National Forest

Author(s):  
Timothy L Porter ◽  
◽  
TR Dillingham ◽  

We have taken near-surface soil measurements of the gases CO2 , CH4 , H2 O and isoprene in several regions of the Coconino National Forest, Arizona, USA. Sets of measurements were taken both prior to the start of the seasonal monsoon season, in addition to while the monsoon season was underway. We have also compared the current monsoon season readings with readings taken at the same locations four years prior. For CO2, the relative level in the pristine forest soil is just under 3.7 percent lower than that measured in 2017, while the CO2 relative levels for the thinned and logged sites are lower by 13.5 and 5.4 percent, respectively. Even accounting for small increases in forest vegetation, these lower readings appear to be correlated to lower overall soil H2 O concentrations. The pristine CH4 relative concentration in 2021 is 9.6% higher and the thinned CH4 level is 19% higher. For the logged region, the measured methane level is over 70% lower than in 2017, but still approximately triple the methane level as seen in the other forest areas. We conclude that this result also may also be correlated to lower measured H2 O levels in the soils.

2020 ◽  
Vol 191 ◽  
pp. 3
Author(s):  
Anatolyi Kotsarenko ◽  
Vsevolod Yutsis ◽  
Vladimir Grimalsky ◽  
Svetlana Koshevaya ◽  
Yuryi Kotsarenko

This article describes anomalous changes in the diurnal behavior of the temperature measured in the near-surface soil at the Tlamacas monitoring site, Popocatépetl. Results of the statistical analysis show two essential changes for the temperature characteristics observed during the 2007–2009 (quiet volcano) and 2013–2014 (active volcano) monitoring periods. Under normal conditions, the absolute minimum daily temperature is observed at about 7:40 Local Time (LT) during sunrise for the atmosphere and, with a time delay, at about 8:30 LT, for soil measurements. The absolute temperature maximum is observed about 15:30 LT for the atmosphere and 16:30 LT for in-soil measurements. The dispersion of the residual temperature (24-h running trend of the temperature substituted) is 5.6 times lower for the 2013–2014 period in comparison with the 2007–2009 period. In other words, in 2013–2014, the temperature variability became 5.6 times lower that it was in 2007–2009.


2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.


2014 ◽  
Vol 27 (8) ◽  
pp. 1805-1812 ◽  
Author(s):  
Maarten De Boever ◽  
Donald Gabriels ◽  
Mohamed Ouessar ◽  
Wim Cornelis

2021 ◽  
pp. 1-10
Author(s):  
X.M. Yang ◽  
W.D. Reynolds ◽  
C.F. Drury ◽  
M.D. Reeb

Although it is well established that soil temperature has substantial effects on the agri-environmental performance of crop production, little is known of soil temperatures under living cover crops. Consequently, soil temperatures under a crimson clover and white clover mix, hairy vetch, and red clover were measured for a cool, humid Brookston clay loam under a corn–soybean–winter wheat/cover crop rotation. Measurements were collected from August (after cover crop seeding) to the following May (before cover crop termination) at 15, 30, 45, and 60 cm depths during 2018–2019 and 2019–2020. Average soil temperatures (August–May) were not affected by cover crop species at any depth, or by air temperature at 60 cm depth. During winter, soil temperatures at 15, 30, and 45 cm depths were greater under cover crops than under a no cover crop control (CK), with maximum increase occurring at 15 cm on 31 January 2019 (2.5–5.7 °C) and on 23 January 2020 (0.8–1.9 °C). In spring, soil temperatures under standing cover crops were cooler than the CK by 0.1–3.0 °C at 15 cm depth, by 0–2.4 °C at the 30 and 45 cm depths, and by 0–1.8 °C at 60 cm depth. In addition, springtime soil temperature at 15 cm depth decreased by about 0.24 °C for every 1 Mg·ha−1 increase in live cover crop biomass. Relative to bare soil, cover crops increased near-surface soil temperature during winter but decreased near-surface soil temperature during spring. These temperature changes may have both positive and negative effects on the agri-environmental performance of crop production.


2013 ◽  
Vol 40 (6) ◽  
pp. 1074-1078 ◽  
Author(s):  
Ranajit Ghose ◽  
Joao Carvalho ◽  
Afonso Loureiro

2011 ◽  
Vol 8 (6) ◽  
pp. 1499-1519 ◽  
Author(s):  
A. Dallmeyer ◽  
M. Claussen

Abstract. Using the general circulation model ECHAM5/JSBACH, we investigate the biogeophysical effect of large-scale afforestation and deforestation in the Asian monsoon domain on present-day and mid-Holocene climate. We demonstrate that the applied land cover change does not only modify the local climate but also change the climate in North Africa and the Middle East via teleconnections. Deforestation in the Asian monsoon domain enhances the rainfall in North Africa. In parts of the Sahara summer precipitation is more than doubled. In contrast, afforestation strongly decreases summer rainfall in the Middle East and even leads to the cessation of the rainfall-activity in some parts of this region. Regarding the local climate, deforestation results in a reduction of precipitation and a cooler climate as grass mostly has a higher albedo than forests. However, in the core region of the Asian monsoon the decrease in evaporative cooling in the monsoon season overcompensates this signal and results in a net warming. Afforestation has mainly the opposite effect, although the pattern of change is less clear. It leads to more precipitation in most parts of the Asian monsoon domain and a warmer climate except for the southern regions where a stronger evaporation decreases near-surface temperatures in the monsoon season. When prescribing mid-Holocene insolation, the pattern of local precipitation change differs. Afforestation particularly increases monsoon rainfall in the region along the Yellow River which was the settlement area of major prehistoric cultures. In this region, the effect of land cover change on precipitation is half as large as the orbitally-induced precipitation change. Thus, our model results reveal that mid- to late-Holocene land cover change could strongly have contributed to the decreasing Asian monsoon precipitation during the Holocene known from reconstructions.


Sign in / Sign up

Export Citation Format

Share Document