Dependence of the aboveground respiration of hinoki cypress (Chamaecyparis obtusa) on tree size

Nighttime respiration was measured at monthly intervals over one year on the aboveground parts of five sample trees in an 8-year-old hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) stand, by an enclosed standing-tree method. The respiration rate rose rapidly from early spring to a maximum in June, and decreased abruptly in July and then gradually toward autumn and winter. The seasonal change in the respiration rate was synchronized with stem volume increment rather than with monthly mean air temperature. The respiration rate, r, of individual trees increased with increasing tree dimensions, such as stem volume, v(S), and stem girth at the base of the live crown, G(B). The dependence of respiration rate on tree size was successfully represented by a power function. The r - v(S) dependence was rather stronger than the r - G(B) (2) dependence, especially toward the end of the growing season (from July to September). The observed respiration rate was almost the same as the respiration rate corrected for the monthly mean air temperature. The annual respiration of individual trees was directly proportional to their phytomass or to its increment. Although the annual respiration of individual trees decreased proportionally to the square root of the leaf mass, it decreased abruptly in the range close to the smallest sample tree. Combining the monthly relationship between respiration rate and stem volume with the tree size distribution in the stand, the stand aboveground annual respiration was estimated to be 20.4 Mg CO(2) ha(-1) year(-1) (= 12.5 Mg dry mass ha(-1) year(-1)) for an aboveground biomass of 17.4 Mg ha(-1) with an annual increment of 6.51 Mg ha(-1) year(-1), i.e., the stand aboveground annual respiration amounted to the equivalent of 72% of the biomass or to almost twice the biomass increment.     

Tree size dependence of litter production, and above-ground net production in a young Hinoki (Chamaecyparis obtusa) stand

The study was carried out in a 9-year-old hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.), stand over a span of three years from July 1992 to June 1995, primarily to predict litter production from exteral tree dimensions by combining open-top clothtrap and clipping methods. Litter production was virtually concentrated in October and November. Stem cross-sectional area at the crown base was proved to be the reliable predictor of litter production, and that single regression model was evolved irrespective of year. The regression model had proportional constants of 2.696 × 10⁻² and 3.540 × 10⁻² kg cm⁻² year⁻¹ for leaf litter and total litter production, respectively. Utilizing the model, leaf litter production of the stand was assessed to be 5.04, 5.12, and 4.99, and total litter production to be 6.48, 6.58, and 6.40 Mg ha⁻¹ year⁻¹ for the first, second and third year, respectively. Biomass increment was 6.67, 7.80, and 7.70, tree mortality was 0.15, 0.13, and 0.41, and insect grazing was 0.09, 0.05, and 0.002 Mg ha⁻¹ year⁻¹ for the first, second and third year, respectively. Above-groud net production was therefore 13.39, 14.55, and 14.51, Mg ha⁻¹ year⁻¹, and biomass accumulation ratio (biomass/net production) was 1.86, 2.21, and 2.76 year for the first, second and third year, respectively. Considering data from earlier studies and the results of this study, biomass accumulation ratio,BAR (year), of hinoki stands was best related to above-ground biomass,y (Mg ha⁻¹), using the power function:BAR=0.112y ^0.936. Excluding seedling stands, leaf efficiency (above-ground net production per unit leaf mass) of hinoki stands was 0.91±0.02 (SE) Mg Mg⁻¹ year⁻¹, irrespective of stand biomass or age.     

Use of microsatellite marker Pi26 for rapid discrimination of five Japanese genotypes of Phytophthora infestans

Microsatellite markers were tested to rapidly discriminate five Japanese genotypes (US-1, JP-1, JP-2, JP-3, and JP-4) of Phytophthora infestans. Collected from 1958 to 2007, 111 isolates of Japanese P. infestans were examined using a fluorescent-labeled primer and capillary electrophoresis. Microsatellite marker Pi26 generated specific products for each genotype without any differences in terms of isolation area or year for a particular genotype. The Pi26 marker is a powerful tool for obtaining information on the structure of Japanese populations of P. infestans.     

A model of seasonal foliage dynamics of the subtropical mangrove species Rhizophora stylosa Griff.growing at the northern limit of its distribution

Background： Progress of forest production in response to the environment requires a quantitative understanding of leaf area development. Therefore, it is necessary to investigate the dynamics of seasonal crown foliage in order to understand the productivity of mangroves, which play an important role in the subtropical and tropical coastlines of the world. Method： Crown foliage dynamics of the mangrove Rhizophora styloso were studies to reveal patterns of leaf recruitment, survival and seasonal leaf area growth. Results： Flushing of leaves occurred throughout the year, but both flushing and leaf area growth pattern of leaves varied with season. Maximum flushing occurred in summer, but leaf areas did not differ significantly with season. The half-expansion period is longer, and the intrinsic rate of increase was lower in winter. Summer flushed leaves grew faster at their initial stage and reached their maximum area over a shorter period of time. The difference in temperature and air vapor pressure deficit （VPD） between summer and winter contributed to the present dynamics of foliage patterns. The mean leaf longevity was estimated to be 13.1 month. The crown foliage area was almost stable throughout the year. Conclusions： Homeostatic control of the crown foliage area may be accompanied by the existence of ecophysiological mechanisms in R. stylosa. Integrating crown foliage dynamics into forest models represents an important step towards incorporating physiological mechanisms into the models for predicting growth responses to environmental changes and for understanding the complex responses of tree growth and litter production.     

The effectiveness of a new physical property evaluation method of kamaboko which applied the principal component analysis to the puncture and stress relaxation tests

ABSTRACT:   The physical properties of 49 commercial kamabokos were measured by the puncture and stress relaxation tests. The principal component analysis was applied to the physical parameters of both tests, and their cumulative contribution ratios were over 90% with the first and second principal components, respectively. The comparison among the kamabokos was carried out using the synthetic physical parameters. The kamabokos produced in same area showed the peculiar distribution. The relative positional relation of kamabokos measured by the stress relaxation test was different from that by the puncture test for many of the kamabokos. Physical property evaluation using a principal component analysis is very effective for intensiveness of many measurement parameters. If much more kamabokos were measured by this method, regional characteristics of kamabokos would be clarified.     

Genetic relationships between the dominant genotypes of Phytophthora infestans in Hokkaido, Japan

The genetic characteristics of the dominant genotypes of Phytophthora infestans in Japan (US-1, JP-1, Japanese A1-A, A1-B) were compared. Differences were evident in the peptidase genotype, amplified fragment length polymorphism, and RG57 DNA fingerprints. Almost all of the fingerprint bands for the Japanese genotype A1-B were also present in JP-1 and Japanese A1-A, and few bands were unique to Japanese A1-B. These results suggest that the Japanese A1-B genotype was generated from sexual reproduction involving Japanese A1-A and JP-1 or related genotypes.     

Sexual mating preferences in vitro and in planta among Japanese isolates of Phytophthora infestans

The sexual preferences of Japanese isolates of Phytophthora infestans were determined by mating on agar, in broth, or in plants. The influence of their sexual preference was confirmed in the host tissues. Three wild-type isolates and a -glucuronidase (GUS) transformant were co-cultured to identify the origin of antheridia and oogonia. Japanese A1 isolate had a unique sexual preference compared with foreign isolates. It produced self-fertile oospores with about 40% of total gametangia but tended to form antheridia on V-8 agar medium. In addition, oospores were formed in plants, but their sexual preference could not be reflected in vitro.     

Ensiling characteristics of total mixed ration prepared with local feed resources in Mozambique and their effects on nutrition value and milk production in Jersey dairy cattle

To effectively utilize total mixed ration (TMR) prepared with locally available feed resources, we studied the nutritional value and milk production in Jersey dairy cattle fed a local general diet (LGD) and fermented TMR in Mozambique. Ten head of Jersey dairy cattle with 337 ± 19.8 kg body weight, aged 3–4 years in mid location were used in this study. The LGD diet was designed following the general feeding method of local smallholding farms; it contained native grass, Napier grass, wheat bran, and mineral–vitamin mix. Fermented TMR was prepared using Napier grass, corn bran, wheat bran, formula feed, and mineral–vitamin mix. Fermented TMR was preserved as good quality, with a relatively low pH and high lactic acid content. Compared to LGD, fermented TMR significantly improved the dry matter intake and digestibility in dairy cattle. Milk yield was significantly higher in dairy cattle fed with TMR than in those fed with LGD, by 3.75 L/d; milk quality was not significantly different between treatments. The results confirmed that LGD had a low dry matter intake and milk yield, and fermented TMR prepared with local feed resources can attain good quality and improve milk yield in dairy cattle in Mozambique.     

Effects of elevated CO2 concentration on the respiratory behavior of the branches of field-grown hinoki cypress (Chamaecyparis obtusa)

The effects of elevated atmospheric CO₂ concentrations on the nighttime respiration were examined for two sample branches of a hinoki cypress tree (Chamaecyparis obtusa) growing in the field with an open gas exchange system for a one-year period from July 1994 to June 1995. The branches were of a similar size and located at a similar position within the crown. One branch was subjected to an elevated CO₂ concentration of 800 μmol mol⁻¹ and the other was subjected to ambient air which had a CO₂ concentration of about 370 μmol mol⁻¹. Nighttime respiration rate was higher in elevated CO₂ level than in ambient CO₂ level. The relationship between nighttime respiration and the corresponding nighttime air temperature was fitted by the exponential function in every month of the year. The segregation of regression lines between the two CO₂ treatments increased gradually as the seasons progressed during the treatment period. TheQ ₁₀ values for nighttime respiration were lower in elevated CO₂ (1.9 ≤Q ₁₀ ≤ 3.7) than in ambient CO₂ (2.4 ≤Q ₁₀ ≤ 4.5) in every month of the year. TheQ ₁₀ was inversely related to the monthly mean nighttime air temperature in both elevated and ambient CO₂. The estimated daily nighttime respiration rate under both CO₂ treatments had a similar seasonal pattern, which almost synchronized with the temperature change. The respiration ratio of elevated CO₂ to ambient CO₂ increased gradually from 1.1 to 1.6 until the end of the experiment. Our results indicate that the CO₂ level and the temperature have a strong interactive effect on respiration and suggest that a potential increase in respiration of branches will occur when ambient CO₂ increases.     

Anguilla huangi Teng, Lin, and Tzeng, 2009, is a junior synonym of Anguilla luzonensis Watanabe, Aoyama, and Tsukamoto, 2009

Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.