Why are East Asian ecosystems important for carbon cycle research?

Fang, Jingyun,Tang, Yanhong,Son, Yowhan Jointly published by Science China Press and Sprin 2010 Science China. Life sciences Vol.53 No.7

Changes in the distribution of South Korean forest vegetation simulated using thermal gradient indices.

Choi, Sungho,Lee, Woo-Kyun,Son, Yowhan,Yoo, Seongjin,Lim, Jong-Hwan Jointly published by Science China Press and Sprin 2010 Science China. Life sciences Vol.53 No.7

<P>To predict changes in South Korean vegetation distribution, the Warmth Index (WI) and the Minimum Temperature of the Coldest Month Index (MTCI) were used. Historical climate data of the past 30 years, from 1971 to 2000, was obtained from the Korea Meteorological Administration. The Fifth-Generation National Center for Atmospheric Research (NCAR) /Penn State Mesoscale Model (MM5) was used as a source for future climatic data under the A1B scenario from the Special Report on Emission Scenario (SRES) of the Intergovernmental Panel on Climate Change (IPCC). To simulate future vegetation distribution due to climate change, the optimal habitat ranges of Korean tree species were delimited by the thermal gradient indices, such as WI and MTCI. To categorize the Thermal Analogy Groups (TAGs) for the tree species, the WI and MTCI were orthogonally plotted on a two-dimensional grid map. The TAGs were then designated by the analogue composition of tree species belonging to the optimal WI and MTCI ranges. As a result of the clustering process, 22 TAGs were generated to explain the forest vegetation distribution in Korea. The primary change in distribution for these TAGs will likely be in the shrinkage of areas for the TAGs related to Pinus densiflora and P. koraiensis, and in the expansion of the other TAG areas, mainly occupied by evergreen broad-leaved trees, such as Camellia japonica, Cyclobalanopsis glauca, and Schima superba. Using the TAGs to explain the effects of climate change on vegetation distribution on a more regional scale resulted in greater detail than previously used global or continental scale vegetation models.</P>

Encoding-based brain-computer interface controlled by non-motor area of rat brain.

Lang, Yiran,Du, Ping,Shin, Hyung-Cheul Jointly published by Science China Press and Sprin 2011 Science China. Life sciences Vol.54 No.9

<P>As the needs of disabled patients are increasingly recognized in society, researchers have begun to use single neuron activity to construct brain-computer interfaces (BCI), designed to facilitate the daily lives of individuals with physical disabilities. BCI systems typically allow users to control computer programs or external devices via signals produced in the motor or pre-motor areas of the brain, rather than producing actual motor movements. However, impairments in these brain areas can hinder the application of BCI. The current paper demonstrates the feasibility of a one-dimensional (1D) machine controlled by rat prefrontal cortex (PFC) neurons using an encoding method. In this novel system, rats are able to quench thirst by varying neuronal firing rate in the PFC to manipulate a water dish that can rotate in 1D. The results revealed that control commands generated by an appropriate firing frequency in rat PFC exhibited performance improvements with practice, indicated by increasing water-drinking duration and frequency. These results demonstrated that it is possible for rats to understand an encoding-based BCI system and control a 1D machine using PFC activity to obtain reward.</P>

Spatio-temporal change in forest cover and carbon storage considering actual and potential forest cover in South Korea.

Nam, Kijun,Lee, Woo-Kyun,Kim, Moonil,Kwak, Doo-Ahn,Byun, Woo-Hyuk,Yu, Hangnan,Kwak, Hanbin,Kwon, Taesung,Sung, Joohan,Chung, Dong-Jun,Lee, Seung-Ho Jointly published by Science China Press and Sprin 2015 Science China. Life sciences Vol.58 No.7

<P>This study analyzes change in carbon storage by applying forest growth models and final cutting age to actual and potential forest cover for six major tree species in South Korea. Using National Forest Inventory data, the growth models were developed to estimate mean diameter at breast height, tree height, and number of trees for Pinus densiflora, Pinus koraiensis, Pinus rigida, Larix kaempferi, Castanea crenata and Quercus spp. stands. We assumed that actual forest cover in a forest type map will change into potential forest covers according to the Hydrological and Thermal Analogy Groups model. When actual forest cover reaches the final cutting age, forest volume and carbon storage are estimated by changed forest cover and its growth model. Forest volume between 2010 and 2110 would increase from 126.73 to 157.33 m(3) hm(-2). Our results also show that forest cover, volume, and carbon storage could abruptly change by 2060. This is attributed to the fact that most forests are presumed to reach final cutting age. To avoid such dramatic change, a regeneration and yield control scheme should be prepared and implemented in a way that ensures balance in forest practice and yield.</P>

Spontaneous high-frequency action potential.

Shen, Haiying,Choe, Wonchae Jointly published by Science China Press and Sprin 2011 Science China. Life sciences Vol.54 No.4

<P>Action potential, which is the foundation of physiology and electrophysiology, is most vital in physiological research. This work starts by detecting cardiac electrophysiology (tachyarrhythmias), combined with all spontaneous discharge phenomena in vivo such as wound currents and spontaneous neuropathic pain, elaborates from generation, induction, initiation, to all of the features of spontaneous high-frequency action potential-SSL action potential mechanism, i.e., connecting-end hyperpolarization initiates spontaneous depolarization and action potential in somatic membrane. This work resolves the conundrums of in vivo spontaneous discharge in tachyarrhythmias, wounds, denervation supersensitivity, neurogenic pain (hyperalgesia and allodynia), epileptic discharge and diabetic pain in pathophysiological and clinical researches that have puzzled people for a hundred years.</P>

Protocruzia, a highly ambiguous ciliate (Protozoa; Ciliophora): Very likely an ancestral form for Heterotrichea, Colpodea or Spirotrichea? With reevaluation of its evolutionary position based on multigene analyses.

Li, Lifang,Thorsten, Stoeck,Kyoon, Shin Mann,Al-Rasheid Khaled, A S,Al-Khedhairy Bdulaziz, A,Song, Weibo Jointly published by Science China Press and Sprin 2010 Science China. Life sciences Vol.53 No.1

<P>The ciliate genus Protocruzia belongs to one of the most ambiguous taxa considering its systematic position, possible as a member of the classes Heterotrichea, Spirotrichea or Karyorelictea, which is tentatively placed into Spirotrichea in Lynn's 2008 system. To test these hypotheses, multigene trees (Bayesian inference, evolutionary distance, maximum parsimony, and maximum likelihood) were constructed using the small subunit rRNA (SSU rRNA) gene, internal transcribed spacer 2 (ITS2) and a protein coding gene (histone H4). All analyses agree that: (1) four morphotypes of Protocruzia from different geographical origins group together and form a monophyletic clade, which cannot be assigned to any of the eleven described ciliate classes; (2) it is invariably positioned on an isolated branch separated from the class Spirotrichea suggesting that this clade should be clearly removed from Spirotrichea; (3) this leads us to hypothesize that this taxon may indeed represent a lineage on a class rank. Based on the fact that it is, both morphologically and in molecular features, closely related to heterotrichs, Colpodea and Oligohymenophorea, Protocruziida might be an ancestral form for the subphylum Intramacronucleata in the evolutionary line from the class Heterotrichea (subphylum Postciliodesmatophora) to higher taxa.</P>

Carbon and nitrogen storage in an age-sequence of Pinus densiflora stands in Korea.

Noh, Nam-Jin,Son, Yowhan,Lee, Sue-Kyoung,Seo, Kyung-Won,Heo, Su-Jin,Yi, Myong-Jong,Park, Pil-Sun,Kim, Rae-Hyun,Son, Yeong-Mo,Lee, Kyeong-Hak Jointly published by Science China Press and Sprin 2010 Science China. Life sciences Vol.53 No.7

<P>The carbon (C) and nitrogen (N) storage capabilities of Pinus densiflora in six different stand ages (10, 27, 30, 32, 44, and 71 years old) were investigated in Korea. Thirty sample trees were destructively harvested and 12 were excavated. Samples from the above and belowground tree components, coarse woody debris (CWD), forest floor, and mineral soil (0-30 cm) were collected. Tree biomass was highest in the 71-year-old stand (202.8 t ha(-1)) and lowest in the 10-year-old stand (18.4 t ha(-1)). C and N storage in the mineral soil was higher in the 71-year-old stand than in the other stands, mainly due to higher soil C and N concentrations. Consequently, the total ecosystem C and N storage (tree+forest floor+CWD+soil) was positively correlated with stand age: increasing from a minimum in the 10 year old stand (18.8 t C ha(-1) and 1.3 t N ha(-1)) to a maximum in the 71-year-old stand (201.4 t C ha(-1) and 8.5 t N ha(-1)). The total ecosystem C storage showed a similar sigmoidal pattern to that of tree C storage as a function of the age-sequence, while N storage in the CWD, forest floor and mineral soil showed no significant temporal trends. Our results provide important insights that will increase our understanding of C and N storage in P. densiflora stands and our ability to predict changes according to stand age in the region.</P>

Estimation of carbon storage based on individual tree detection in Pinus densiflora stands using a fusion of aerial photography and LiDAR data.

Kim, So-Ra,Kwak, Doo-Ahn,Olee, Woo-Kyun,Son, Yowhan,Bae, Sang-Won,Kim, Choonsig,Yoo, Seongjin Jointly published by Science China Press and Sprin 2010 Science China. Life sciences Vol.53 No.7

<P>The objective of this study was to estimate the carbon storage capacity of Pinus densiflora stands using remotely sensed data by combining digital aerial photography with light detection and ranging (LiDAR) data. A digital canopy model (DCM), generated from the LiDAR data, was combined with aerial photography for segmenting crowns of individual trees. To eliminate errors in over and under-segmentation, the combined image was smoothed using a Gaussian filtering method. The processed image was then segmented into individual trees using a marker-controlled watershed segmentation method. After measuring the crown area from the segmented individual trees, the individual tree diameter at breast height (DBH) was estimated using a regression function developed from the relationship observed between the field-measured DBH and crown area. The above ground biomass of individual trees could be calculated by an image-derived DBH using a regression function developed by the Korea Forest Research Institute. The carbon storage, based on individual trees, was estimated by simple multiplication using the carbon conversion index (0.5), as suggested in guidelines from the Intergovernmental Panel on Climate Change. The mean carbon storage per individual tree was estimated and then compared with the field-measured value. This study suggested that the biomass and carbon storage in a large forest area can be effectively estimated using aerial photographs and LiDAR data.</P>