Effects of silviculture treatments in a hurricane-damaged forest on carbon storage and emissions in central Hokkaido,Japan   总被引：1，自引：0，他引：1  

Toshiaki Owari  Naoto Kamata  Takeshi Tange  Mikio Kaji  Akio Shimomura 《林业研究》2011,21(1):13-20

Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm (understory vegetation removal) led to the largest amount of carbon stored (64.7 t·ha-1 C). Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid (L. gmelinii var. japonica × L. kaempferi) plantation (80.3 t·ha-1 C). The plantation of Abies sachalinensis was not successful at accumulating carbon (40.5·ha-1 C). The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.  相似文献   

Soil nitrogen dynamics of forest ecosystems under environmental changes     

Hideaki Shibata  Hiroto Toda  Yoshiyuki Inagaki  Ryunosuke Tateno  Keisuke Koba  Takeshi Tange 《Journal of Forest Research》2011,16(5):331-332

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Comparative Evaluation on Nitrogen Saturation of Forest Catchments in Japan and Northeastern United States     

Nobuhito Ohte  Myron J. Mitchell  Hideaki Shibata  Naoko Tokuchi  Hiroto Toda  Goro Iwatsubo 《Water, air, and soil pollution》2001,130(1-4):649-654

To analyze the differences in the status and processes of nitrogen saturation in Japan and northeastern United States, we examined the hydrobiogeochemistry of nitrogen of forested watersheds in these regions. Two distinct differences were found between watersheds in Japan compared with those in US. 1) In Japanese watersheds, marked decreases of NO₃ ^? concentration in surface waters during the summer growing season were not found and NO₃ ^? concentrations sometimes increased especially in the summer at nitrogen saturated sites. This contrast with watersheds in US where decreases in NO₃ ^? concentration during the summer are commonly observed except those watersheds in advanced stages of nitrogen saturation. These differences in NO₃ ^? concentration relationships can be attributed to climatic differences, with Japan having high precipitation and high discharge during the summer, while in many regions of North America lowest discharges are found in the summer. The climatic regime in Japan leads to high rates of mineralization and the rapid transport of NO₃ ^? to streams in summer. 2) Japanese watersheds, even those with high NO₃ ^? concentrations in surface waters, show little evidence of acidification. This is in contrast to sites in US where increased NO₃ ^? concentrations, especially during episodic events, result in surface water acidification.  相似文献   

Mutations in dynein link motor neuron degeneration to defects in retrograde transport     

Hafezparast M  Klocke R  Ruhrberg C  Marquardt A  Ahmad-Annuar A  Bowen S  Lalli G  Witherden AS  Hummerich H  Nicholson S  Morgan PJ  Oozageer R  Priestley JV  Averill S  King VR  Ball S  Peters J  Toda T  Yamamoto A  Hiraoka Y  Augustin M  Korthaus D  Wattler S  Wabnitz P  Dickneite C  Lampel S  Boehme F  Peraus G  Popp A  Rudelius M  Schlegel J  Fuchs H  Hrabe de Angelis M  Schiavo G  Shima DT  Russ AP  Stumm G  Martin JE  Fisher EM 《Science (New York, N.Y.)》2003,300(5620):808-812

Degenerative disorders of motor neurons include a range of progressive fatal diseases such as amyotrophic lateral sclerosis (ALS), spinal-bulbar muscular atrophy (SBMA), and spinal muscular atrophy (SMA). Although the causative genetic alterations are known for some cases, the molecular basis of many SMA and SBMA-like syndromes and most ALS cases is unknown. Here we show that missense point mutations in the cytoplasmic dynein heavy chain result in progressive motor neuron degeneration in heterozygous mice, and in homozygotes this is accompanied by the formation of Lewy-like inclusion bodies, thus resembling key features of human pathology. These mutations exclusively perturb neuron-specific functions of dynein.  相似文献   

High-density electron anions in a nanoporous single crystal: [Ca24Al28O64]4+(4e-)   总被引：1，自引：0，他引：1  

Matsuishi S  Toda Y  Miyakawa M  Hayashi K  Kamiya T  Hirano M  Tanaka I  Hosono H 《Science (New York, N.Y.)》2003,301(5633):626-629

We removed approximately 100% of clathrated oxygen ions from the crystallographic cages in a single crystal of 12CaO.7Al2O3, leading to the formation of high-density (approximately 2 x 10(21) cm-3) electrons highly localized in the cages. The resulting electron forms a structure that we interpret as an F+ center and migrates throughout the crystal by hopping to a neighboring cage with conductivity approximately 100 siemens per centimeter, demonstrating that the encaged electron behaves as an anion. The electron anions couple antiferromagnetically with each other, forming a diamagnetic pair or singlet bipolaron. The resulting [Ca24Al28O64]4+(4e-) may be regarded as a thermally and chemically stable single crystalline "electride."  相似文献   

Asynchronous climate changes in the North Atlantic and Japan during the last termination     

Nakagawa T  Kitagawa H  Yasuda Y  Tarasov PE  Nishida K  Gotanda K  Sawai Y;Yangtze River Civilization Program Members 《Science (New York, N.Y.)》2003,299(5607):688-691

Pollen records from the annually laminated sediment sequence in Lake Suigetsu, Japan, suggest a sequence of climate changes during the Last Termination that resembles that of the North Atlantic region but with noticeable differences in timing. An interstadial interval commenced a few centuries earlier [approximately 15,000 years before the present (yr B.P.)] than the North Atlantic GI-1 (B?lling) event. Conversely, the onset of a Younger Dryas (YD)-like cold reversal (12,300 to 11,250 yr B.P.) postdated the North Atlantic GS-1 (YD) event by a few centuries. Climate in the Far East during the Last Termination reflected solar insolation changes as much as Atlantic influences.  相似文献   

Chemistry. Nuclear spin conversion in molecules     

Hougen JT  Oka T 《Science (New York, N.Y.)》2005,310(5756):1913-1914

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Distinct kinetic changes in neurotransmitter release after SNARE protein cleavage     

Sakaba T  Stein A  Jahn R  Neher E 《Science (New York, N.Y.)》2005,309(5733):491-494

Neurotransmitter release is triggered by calcium ions and depends critically on the correct function of three types of SNARE [soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor] proteins. With use of the large calyx of Held presynaptic terminal from rats, we found that cleavage of different SNARE proteins by clostridial neurotoxins caused distinct kinetic changes in neurotransmitter release. When elevating calcium ion concentration directly at the presynaptic terminal with the use of caged calcium, cleavage of SNAP-25 by botulinum toxin A (BoNT/A) produced a strong reduction in the calcium sensitivity for release, whereas cleavage of syntaxin using BoNT/C1 and synaptobrevin using tetanus toxin (TeNT) produced an all-or-nothing block without changing the kinetics of remaining vesicles. When stimulating release by calcium influx through channels, a difference between BoNT/C1 and TeNT emerged, which suggests that cleavage of synaptobrevin modifies the coupling between channels and release-competent vesicles.  相似文献   

Heterochromatin and RNAi are required to establish CENP-A chromatin at centromeres     

Folco HD  Pidoux AL  Urano T  Allshire RC 《Science (New York, N.Y.)》2008,319(5859):94-97

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Mass spectrometry of intact V-type ATPases reveals bound lipids and the effects of nucleotide binding     

Zhou M  Morgner N  Barrera NP  Politis A  Isaacson SC  Matak-Vinković D  Murata T  Bernal RA  Stock D  Robinson CV 《Science (New York, N.Y.)》2011,334(6054):380-385

The ability of electrospray to propel large viruses into a mass spectrometer is established and is rationalized by analogy to the atmospheric transmission of the common cold. Much less clear is the fate of membrane-embedded molecular machines in the gas phase. Here we show that rotary adenosine triphosphatases (ATPases)/synthases from Thermus thermophilus and Enterococcus hirae can be maintained intact with membrane and soluble subunit interactions preserved in vacuum. Mass spectra reveal subunit stoichiometries and the identity of tightly bound lipids within the membrane rotors. Moreover, subcomplexes formed in solution and gas phases reveal the regulatory effects of nucleotide binding on both ATP hydrolysis and proton translocation. Consequently, we can link specific lipid and nucleotide binding with distinct regulatory roles.  相似文献