Simulated nitrogen deposition significantly reduces soil respiration in an evergreen broadleaf forest in western China Shixing Zhou, Yuanbin Xiang, Liehua Tie, Bohan Han, Congde Huang https://doi.org/10.1371/journal.pone.0204661 https://www.researchgate.net/publication/327920145 Abstract Soil respiration is the second largest terrestrial carbon (C) flux; the responses of soil respiration to nitrogen (N) deposition have far-reaching influences on the global C cycle. N deposition has been documented to significantly affect soil respiration, but the results are conflicting. The response of soil respiration to N deposition gradients remains unclear, especially in ecosystems receiving increasing ambient N depositions. A field experiment was conducted in a natural evergreen broadleaf forest in western China from November 2013 to November 2015 to understand the effects of increasing N deposition on soil respiration. Four levels of N deposition were investigated: control (Ctr, without N added), low N (L, 50 kg N ha −1 ·a −1 ), medium N (M, 150 kg N ha −1 ·a −1 ), and high N (H, 300 kg N ha −1 ·a −1 ). The results show that (1) the mean soil respiration rates in the L, M, and H treatments were 9.13%, 15.8% ( P 0.05) and 22.57% ( P 0.05) lower than that in the Ctr treatment (1.56 ± 0.13 μmol·m −2 ·s −1 ), respectively; (2) soil respiration rates showed significant positive exponential and linear relationships with soil temperature and moisture ( P 0.01), respectively. Soil temperature is more important than soil moisture in controlling the soil respiration rate; (3) the Ctr, L, M, and H treatments yielded Q 10 values of 2.98, 2.78, 2.65, and 2.63, respectively. N deposition decreased the temperature sensitivity of soil respiration; (4) simulated N deposition also significantly decreased the microbial biomass C and N, fine root biomass, pH and extractable dissolved organic C ( P 0.05). Overall, the results suggest that soil respiration declines in response to N deposition. The decrease in soil respiration caused by simulated N deposition may occur through decreasing the microbial biomass C and N, fine root biomass, pH and extractable dissolved organic C. Ongoing N deposition may have significant impacts on C cycles and increase C sequestration with the increase in global temperature in evergreen broadleaf forests.
I enjoyed everything about my first visit to Seattle after 11 years, except for the mess at the Sea-Tac airport. So, I was determined to take the Link Light Rail from downtown to Sea-Tac at the end of my visit. (I was also told by a friend that rental car picked up at the airport is usually more expensive, another reason to take a public transportation to the Sea-Tac.) Finding the entrance to the Light Rail was not easy, because it is not marked. Most people would start the trip by taking a bus to the "bus tunnel," from where it's easy to get to the Light Rail. When we finally found the entrance (next to the Nordstrom store), the adventure continued... First, I didn't read every small sign on the way down to the platform. I just wanted to get there. I didn't even bother to use the elevator at the end, just carried my luggage and walked downstairs. When I got there, I didn't know what the Light Rail looked like, and asked a guy in uniform. He said this is where you get on the rail. I looked around and didn't see how I could get a ticket. So, I was sent back upstairs; this time, I used the elevator. Someone helped me to start the conversation with the ticket machine, and the rest was easy. A one-way ticket costs $2.75, and can be purchased using a credit card. No one was there to check the ticket, and we all got on the rail. I was curious about the system, and started to look around. There were some handouts, one of which says "A fine of USD 124" for not having the ticket (or not using the pre-paid card correctly). I wondered if anyone would dare to get on a cheap rail and risk the fine of USD 124. Midway, two guys in uniform showed up to check tickets. To my surprise, two people were "caught" without proper "tickets." One looked like a foreigner (non-Asian), who held dollar bills in her hand. She was lectured, but not fined. The other looked like a student in college. He was told that he didn't initiate the pre-paid card properly, and was put into the city data base for the record. Both were NOT fined. Clearly, the system is still new, and the fine will not come any time soon. The goal is to educate people! Link to the SoundTransit in Seattle: http://www.soundtransit.org/Rider-Guide/Link-light-rail.xml
Jalousie windows are hard to clean, especially when they are old and not well lubricated And I knew I should have cleaned these windows years ago, but there was always something more important to do. Truly, like the income tax return, which is due on the 15th of April. There is no due date for window cleaning, or is there? When I received a letter from the AOAO (Association of Apartment Owners) property manager a few days ago, I knew I had to clean these windows soon or be fined $100. Still, income tax first. So, I worked on my federal tax return on Thursday and the state, on Friday. I mailed them out Saturday morning. What a good feeling (even though I had to write two sizable checks this year)! I knew exactly how I would clean these very dirty windows because I had been thinking, using Paper_towels . I decided long ago paper towels are more environmentally friendly than anything else: all I need is a bit of water to damp them, no washing and no detergent. It took me nearly two hours, but less than one big roll of Bounty. I am so proud of myself, and am looking forward to another letter from the AOAO From Wiki: Spring_cleaning is the period in spring time set aside for cleaning a house, normally applied in climates with a cold winter . The most common usage of spring cleaning refers to the yearly act of cleaning a house from top to bottom which would take place in the first warm days of the year typically in spring, hence the name. However it has also come to be synonymous with any kind of heavy duty cleaning or organizing enterprise. A person who gets their affairs in order before an audit or inspection could be said to be doing some spring cleaning.
标签: fine
