Rapid prediction of wood crystallinity in <Emphasis Type="Italic">Pinus elliotii</Emphasis> plantation wood by near-infrared spectroscopy

Crystallinity is an important property of woody materials; it responds to tree growth traits, structure, and chemical composition, and has a significant effect on Young’s modulus, dimensional stability, density, and hardness, etc. The ability of near-infrared (NIR) spectroscopy coupled with multivariate analysis to rapidly predict the crystallinity of slash pine (Pinus elliotii) plantation wood was investigated. The results showed that the NIR data could be correlated with the X-ray diffraction (XRD)-determined crystallinity of slash pine wood by use of partial least squares (PLS) regression, producing excellent coefficients of determination, r ², and root mean square error of calibration, RMSEC. The use of either reduced spectral ranges or the selection of certain wavelengths consistent with known chemical absorptions did not have any detrimental effect on the quality of PLS models allowing the use of inexpensive, small, and portable spectrometers. These studies show that NIR spectroscopy can be used to rapidly predict the crystallinity of slash pine wood.     

Changes in tree ring width and density ofPinus thunbergii growing in the vicinity of industrial complex in Korea

There has been a decline in tree growth since the operation of factories atPinus thunbergii forests around a petrochemical industrial complex in Korea. This study was carried out to investigate the effects of air pollution on tree ring width and ring density ofPinus thunbergii. Soft X-ray densitometrical method was used. Decline of ring width was the highest during 3 years immediately after the operation of factories. The percentage of decrease was almost bigger immediately after operation as compared with before. Maximum density (MAXD), and the difference (DD) between maximum density and minimum density (MIND) generally decreased since operation of factories, while minimum density increased in the beginning of operation of factories. There was a significant correlation between ring width and high temperature, and precipitation in the beginning of growing season, respectively. There was also a negative correlation between annual mean concentration of SO₂ and ring width at 5% level (r=−0.627^*). It is suggested that the decline of ring width after operation of factories was due to compound factors of air pollution and climate. The effect of other factors should be still more studied. A part of this paper was presented at the International Workshop on Asian and Pacific Dendrochronology on March 4–9, 1995 in Tsukuba (Forestry and Forest Products Research Institute), Japan.     

Effects of vegetation history on distribution of Al in surface soils of suburban forests in Aichi Prefecture, Japan

This study examined the distribution of water-extractable Al in soils from forest sites near Nagoya in Aichi Prefecture. The mean concentrations of water-extractable Al in surface soils varied markedly among sites, with the values at site FGB (126 mg/kg) higher than those at sites FG (11.8 mg/kg) and FCB (33.8 mg/kg). Comparisons of the acid buffer capacity of vegetation at the sites revealed that forest cover has a higher capacity for neutralization than the denuded state. We found that the effects of acidic accumulation in the surface soils of suburban forests might depend on vegetation history, and that forest soils that once had no vegetation cover accumulated labile Al due to acidification. The phenomenon was particularly distinct on granite bedrock.     

Energy investment in leaves of red maple and co-occurring oaks within a forested watershed

Despite its recent expansion in eastern US forests, red maple (Acer rubrum L.) generally exhibits a low leaf photosynthetic rate, leaf mass per unit area (LMA) and leaf nitrogen concentration ([N]) relative to co-occurring oaks (Quercus spp.). To evaluate these differences from the perspective of leaf energy investment, we compared leaf construction cost (CC) and leaf maintenance cost (MC) with leaf photosynthetic rate at saturating photon flux density and ambient CO2 partial pressure (Amax) in red maple and co-occurring red oak (Quercus rubra L.) and chestnut oak (Quercus prinus L.). We also examined relationships among leaf physiological, biochemical and structural characteristics of upper-canopy leaves of these three species at lower (wetter) and upper (drier) elevation sites of a watershed in the Black Rock Forest, Cornwall, NY, USA. Although A(max), leaf [N], leaf carbon concentration ([C]) and LMA were significantly less in red maple than in either oak species at both sites, CC per unit leaf area of red maple was 28.2 and 35.4% less than that of red oak at the lower and upper site, respectively, and 38.8 and 32% less than that of chestnut oak at the lower and upper site, respectively. Leaf MC per unit leaf area, which was positively associated with leaf CC (r2 = 0.95), was also significantly lower in red maple than in either oak species at both sites. When expressed per unit leaf area, A(max) was positively correlated with both CC (r2 = 0.65) and MC (r2 = 0.59). The cost/benefit ratio of CC/Amax of red maple was significantly less than that of chestnut oak at the lower site, however, CC/A(max) did not exhibit any significant interspecific differences at the upper site. Expressed per unit leaf area, CC was correlated positively with LMA (r2 = 0.90), leaf [N] (r2 = 0.97), and leaf [C] (r2 = 0.89), and negatively correlated with leaf molar carbon to nitrogen ratio (r2 = 0.92). Combined with red maple's general success in many oak-dominated forests, our findings suggest that reduced leaf-level photosynthetic capacity and related leaf characteristics in red maple are partially balanced by lower energy and resource requirements for leaf biomass construction and maintenance, which could enhance the competitive success of this species.     

Chemical and structural characteristics of conifer needles exposed to ambient air pollution

Conifer needles exposed to ambient air pollutants were observed by a scanning electron microscope (SEM). Predominant changes on needles were the breakdown and the aggregation of wax structures on stomatal chambers. However, the mode of destruction in stomatal wax structures was dependent on the pollutants. Ginkgo biloba seemed to be resistant to air pollutants despite higher amounts of sulfur in the foliage.     

The Imperata grasslands of tropical Asia: area, distribution, and typology

The rehabilitation or intensified use of Imperata grasslands will require a much better understanding of their area, distribution, and characteristics. We generated estimates of the area of Imperata grasslands in tropical Asia, and suggested a typology of Imperata grasslands that may be useful to define the pathways toward appropriate land use intensification. We conclude that the area of Imperata grasslands in Asia is about 35 million ha. This about 4% of the total land area. The countries with the largest area of Imperata grasslands are Indonesia (8.5 million ha) and India (8.0 million ha). Those with the largest proportion of their surface area covered with Imperata are Sri Lanka (23%), the Philippines (17%), and Vietnam (9%). Laos, Thailand, Myanmar, and Bangladesh evidently all have similar proportions of their land area infested with Imperata (about 3 to 4%). Malaysia (< 1%), Cambodia (1%), and the southern part of China (2%) have but a minor proportion of their total land area in Imperata. The species was found widely distributed on the full range of soil orders. It occupied both fertile (e.g. some of the Inceptisols and Andisols) and infertile soils (Ultisols and Oxisols) across a wide range of climates and elevations. Imperata lands fall into four mapping scale-related categories: Mega-grasslands, itmacro-grasslands, meso-grasslands, and micro-grasslands. The mega-grasslands are often referred to as sheet Imperata. They are the large contiguous areas of Imperata that would appear on small-scale maps of say 1:1,000,000. We propose that this basic typology be supplemented with a number of additional components that have a key influence on intensification pathways: land quality, market access, and the source of power for tillage. The typology was applied in a case study of Indonesian villages in the vicinity of Imperata grasslands. We propose an international initiative to map and derive a more complete and uniform picture of the area of the Imperata grasslands. This should include selected studies to understand conditions at the local level. These are critical to build the appreciation of change agents for the indigenous systems of resource exploitation, and how they relate to local needs, values and constraints.     

Muscle Protein Hydrolysates and Amino Acid Composition in Fish

Fish muscle, which accounts for 15%–25% of the total protein in fish, is a desirable protein source. Their hydrolysate is in high demand nutritionally as a functional food and thus has high potential added value. The hydrolysate contains physiologically active amino acids and various essential nutrients, the contents of which depend on the source of protein, protease, hydrolysis method, hydrolysis conditions, and degree of hydrolysis. Therefore, it can be utilized for various industrial applications including use in nutraceuticals and pharmaceuticals to help improve the health of humans. This review discusses muscle protein hydrolysates generated from the muscles of various fish species, as well as their amino acid composition, and highlights their functional properties and bioactivity. In addition, the role of the amino acid profile in regulating the biological and physiological activities, nutrition, and bitter taste of hydrolysates is discussed.