Riley encased methodology: principles and processes of mangrove habitat creation and restoration

Riley encased methodology (REM) was developed for the purpose of establishing mangroves along highenergy shorelines, revetments, and bulkheads where natural recruitment no longer occurs and where conventional planting methods are ineffective. The principles of REM include the processes of individual seedling isolation within tubular encasements and adaptation of the juvenile plant to the external environment of the restoration site. The success of REM results from specifications for encasement preparation, propagule or seedling selection, and positioning of both encasements and seedlings according to elevation and tidal regimes.     

COX-2 and sPLA2 inhibitory activity of aqueous extract and polyphenols of Rhizophora mangle (red mangrove)

The aqueous extract of Rhizophora mangle bark and its polyphenolic fractions showed remarkable in vitro antiinflammatory activity in a preliminary study. The low molecular weight fraction exhibited cyclooxygenase-2 inhibitory activity while the total aqueous extract and the low molecular weight fraction showed secretory phospholipase A(2) inhibitory activity.     

Identification of salt tolerant baldcypress (<Emphasis Type="Italic">Taxodium distichum</Emphasis> (L.) Rich) for planting in coastal areas

Coastal baldcypress (Taxodium distichum) forests are being killed in the southern United States as a result of saltwater intrusion. Tank studies have indicated substantial intraspecific variation in salt tolerance within baldcypress populations, but only one field study has been conducted and it used a limited seed source. The major objective of this project was to expand the collection range of baldcypress across the southeastern United States and determine if there are baldcypress populations that can survive and grow in saltwater damaged areas. Seeds were collected in 1996 from eight estuarine areas (James River = VA; Cape Fear River = NC; Winyah Bay = SC; Ogeechee River = GA; Ochlockonee River = FL; Mobile Bay = AL; Biloxi River=MS; Chalmette = LA). Seeds were stratified and planted, and seedlings were grown for 2 years before planting in two abandoned ricefields on Hobcaw Barony near Georgetown, South Carolina in 1999. Salinity levels reached 18.5ppt during 2001 at the peak of the worst drought on record. By 2002, the only seedlings surviving were those from LA, AL, and FL. After 5 years in the field, LA seedlings were the best performers with a mortality rate of only 27%. More detailed analyses of the biologic and genetic characteristics of trees growing in the LA site need to be completed to determine if they represent a source of baldcypress seed possessing greater tolerance to saline conditions. If so, seeds need to be collected and nurseries established to grow seedlings to help restore degraded wetland swamp areas along the Gulf and Atlantic coasts.     

Enrichment of big-leaf mahogany (Swietenia macrophylla King) in logging gaps in Bolivia: The effects of planting method and silvicultural treatments on long-term seedling survival and growth

To insure adequate regeneration and future timber yields of mahogany (Swietenia macrophylla King), many logged forests will have to be restocked through enrichment planting and managed using silvicultural techniques that maintain this species’ long-term survival and growth. This study compared the effects of planting method and two silvicultural treatments on the survival and growth of mahogany seedlings in logging gaps in Bolivia. We tested the hypotheses that survival and growth will be higher among transplanted seedlings than seedlings established from sown seeds and higher in silvicultural treatments that reduce competing vegetation and increase light. The first silvicultural treatment consisted of gaps logged 6 months prior to planting, gaps logged just prior to planting, and gaps treated with herbicide prior to planting. The second treatment, applied 12 months after planting, consisted of manual vegetation cleaning around mahogany seedlings in half of the gaps. The first hypothesis was supported in terms of initial seedling growth but not survival, which was similar between planting methods during the 12-92 months after planting. Transplanted seedlings grew significantly faster than those established from sown seeds during the first year, but this growth advantage disappeared by the second year. Although transplants were 84 cm taller than seed-sown seedlings by the end of the study, this height gain was probably not worth the cost of growing and transplanting seedlings. The second hypothesis was supported in terms of both survival and growth. A significantly greater proportion of seedlings survived in herbicide (62%) compared to 6-month-old (46%) and recent gaps (18%) and in cleaned (51%) versus control gaps (39%). Seedlings initially grew faster in herbicide and recent gaps than in 6-month-old gaps. These differences among silvicultural treatments were largely explained by canopy cover, which, throughout the study, was at least 14% lower in herbicide gaps and 9% lower in cleaned gaps relative to their respective alternatives. By 64 months growth diminished to near zero and no longer differed among gap treatments, despite lower canopy cover in herbicide gaps. By 92 months, saplings in herbicide gaps were only 145 and 77 cm taller than those in recent and 6-month-old gaps, respectively. To maximize survival and growth of mahogany seedlings in logging gaps while minimizing costs, silvicultural strategies should focus on direct seed sowing and appropriately timed interventions (i.e. manual cleaning) to control competing vegetation.     

不同女贞光合和荧光特性比较

以女贞、‘日本金叶女贞’和‘日本银边女贞’为研究对象,对其光合速率和叶绿素快相荧光动力学参数差异及其原因进行了分析.结果表明:三者均表现为阳性植物特征,但金叶和银边女贞的净光合速率(Pn)、表观量子效率和光饱和点皆显著低子女贞,光补偿点皆显著高于女贞,表明金叶和银边女贞的光能利用率显著低于女贞.3(品)种女贞的叶绿素快相荧光动力学曲线均为典型的OJIP曲线,但其荧光动力学参数存在显著差异.金叶女贞的PSⅡ受体侧质体醌库(Sm)容量最小(为女贞和银边女贞的60％～70％),利用光能的效率低;银边女贞PSⅡ反应中心数目(NRC/CSm)最少(为女贞和金叶女贞的40％ ～60％),捕获光能总能力低,最终表现为金叶和银边女贞的光合性能指数(Ics、IABS)均低于女贞.     

A comparison of two stand table projection methods for young Eucalyptus nitens (Maiden) plantations in Chile

The study compares two methods of stand table projection based on data from young Eucalyptus nitens (Maiden) plantations in Chile. The projected diameter distributions were estimated using the methods proposed by Nepal and Somers (1992) [For. Sci. 38 (1992) 120] and Cao and Baldwin (1999) [For. Sci. 45 (1999) 506]. The evaluation compared the observed and estimated diameter distributions for different projection intervals, using the Kolmogorov–Smirnov test and an error index called ‘relative discrepancy’. The evaluation showed that both methods are suitable for application in the Eucalypt plantations. However, the method proposed by Nepal and Somers proved to be more accurate, especially when the projection period extends over 4 years or more. Expected error and bias for the observed and estimated total and merchantable volumes at stand level were also evaluated. The observed error and bias were relatively low for both methods; however, some differences were detected when the volume distributions were analyzed at diameter class level.     

Genetic diversity of Castanopsis acuminatissima (Bl.) A. DC. in northern Thailand and the selection of seed trees for forest restoration

Castanopsis acuminatissima (Bl.) A. DC. is one of a number of framework species which are being planted to restore seasonally dry tropical forests in northern Thailand. This study describes the level of microsatellite variation within and among three populations of this species in three National Parks in northern Thailand: Doi Suthep-Pui, Doi Inthanon and Jae Sawn, using published primers developed for Castanopsis cuspidata var. sieboldii Nakai. The five microsatellite loci employed in this study detected a total of 54 alleles (n = 72). The informativeness of the microsatellite loci varied from six to 18 alleles, with an average of 10.8 alleles found over all loci. The mean observed heterozygosities in the three populations showed no significant deviations from Hardy-Weinberg expectations. The vast majority of genetic diversity was contained within the populations, with no significant differentiation between them (F_ST = 0.006). Algorithms were designed to capture microsatellite diversity, and the rationale for using microsatellite markers to inform genetic conservation is discussed. The implications for seed collection of C. acuminatissima for forest restoration are also discussed.     

Components of the essential oils of Azadirachta indica A. Juss, Azadirachta siamensis Velton, and Azadirachta excelsa (Jack) Jacobs and their comparison

The components of the essential oils from seeds of Azadirachta indica, Azadirachta siamensis, and Azadi-rachta excelsa were studied by gas chromatography and gas chromatography-mass spectrometry. The main components of A. indica oil were hexadecanoic acid (34.0%), oleic acid (15.7%), 5,6-dihydro-2,4,6-triethyl-(4H)-1,3,5-dithiazine (11.7%), methyl oleate (3.8%), and eudesm-7(11)-en-4-ol (2.7%). The major components of A. siamensis oil were hexadecanoic acid (52.2%), tricosane (10.5%), tetradecanoic acid (6.8%), oleic acid (4.9%), and pentacosane (4.9%). Azadirachta excelsa oil contained oleic acid (31.3%), hexadecanoic acid (14.2%), octadecanoic acid (13.0%), 4-octylphenol (9.7%), and O-methyloximedecanal (6.8%) as the main constituents. The essential oils from A. indica, A. siamensis, and A. excelsa were found to contain fatty acids (52.6%–72.3%) as major components. The minor components of the oils were n-alkanes, aromatics, esters, sulfur and nitrogen compounds, and terpenoids. Differences in oil composition were observed between the three species.     

A comparison of riparian plant community response to herbivory by beavers (Castor canadensis) and ungulates in Canada's boreal mixed-wood forest

Herbivores, such as beavers (Castor canadensis) and ungulates, can dramatically alter the species composition and structure of riparian vegetation communities. We examined how four different levels of beaver presence and ungulate density influenced the structure and composition of riparian vegetation communities in the mixed-wood boreal region of east-central Alberta, Canada. Beavers, as central-place foragers, focus on similar species utilized by the six ungulate species in our study area. However, we found that vegetation responded differently relative to the percent cover and heights of emergent, shrub, herbaceous dicots, and tree species depending on the varying combinations of beaver presence and ungulate densities. There was an obvious negative effect of ungulate herbivory on shrub heights and cover; however, we were unable to find any significant effects on the overall composition and structure of vegetation communities that were exclusively related to beaver activities. In areas with no beavers and lower ungulate densities there was a positive growth response in preferred species (e.g., Salix spp., Prunus spp.), which clearly demonstrated the degree of combined influence that these herbivores have on riparian communities. In these areas, Salix spp. was four times shorter than in areas where beavers were not present and ungulate densities were lower. In addition percent cover was lowest for emergent vegetation and herbaceous dicots in areas with higher ungulate densities. Many studies focus on single-species effects on forage resources, yet our research shows that the study of combined effects of multiple herbivores can provide a new insight into these complex systems.     

校园环境景观认知调查——以中国矿业大学南湖校区为例

文章针对中国矿业大学南湖校区的景观建设效果,分别对普通人群和专家进行问卷调查,结果表明:专家和普通人群对中国矿业大学南湖校区景观的评价是相似的;校区的秋季景观优于其他季节的景观。       

A comparison between decay patterns of the white‐rot fungus Pleurotus ostreatus in chestnut–leaved oak (Quercus castaneifolia) shows predominantly simultaneous attack both in vivo and in vitro

In this research, we examined decay patterns occurring in Quercus castaneifolia wood under natural conditions compared with controlled decay in vivo. Pleurotus ostreatus‐infected oak wood was obtained from the Sari forests in the north of Iran. The species causing decay was verified as P. ostreatus using rDNA‐ITS sequencing of pure cultures from infected sapwood. In addition to P. ostreatus, two wood‐inhabiting Ascomycota, Trichoderma harzianum and T. lixii, were present. Mass loss in oak sapwood samples exposed to P. ostreatus for 60 days was around 10 per cent. Samples were prepared from both naturally decayed wood and wood decayed under controlled conditions and examined using microscopy. P. ostreatus was found to produce a simultaneous white‐rot decay pattern in both conditions.     

Allometric model of the Reineke equation for Japanese cypress (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>) and red pine (<Emphasis Type="Italic">Pinus densiflora</Emphasis>) stands

An allometric model that explains the mechanism of the difference in the slope of the Reineke equation (A) among species was proposed based on the allometric relationships of mean tree height (H) to quadratic mean diameter D (H ∝ D ^θ ) and stand density N (H ∝ N ^δ ), i.e., A = θ/δ. The proposed model was fitted to Japanese cypress (Chamaecyparis obtusa Endl.) and red pine (Pinus densiflora) stands. The allometric exponents θ and δ were, respectively, 0.8995 and −0.5000 for cypress and 0.8612 and −0.6619 for pine. The difference between cypress and pine was significant for δ but not for θ. Inserting the exponents into the model resulted in predicted slopes of −1.7991 for cypress and −1.3011 for pine. The difference in the slope of the Reineke equation between the two species was produced by characteristics related to the tree crown, rather than characteristics related to stem slenderness. The proposed model enables us to estimate the slope of the Reineke equation from commonly measured stand attributes, such as mean tree height and quadratic mean diameter. Therefore, the proposed model is expected to be practical and convenient for estimating the slope of the Reineke equation and for explaining the mechanism of its variation among species. The model should be also accepted as a generalized model of the stand density versus quadratic mean diameter relationship, whereas the original Reineke equation should be seen as a specific case of this model.     

A new species,first report of a male and new distributional records for five species of Oligosita Walker(Hymenoptera:Trichogrammatidae) from China

Seven species of the genus Oligosita, a wellknown cosmopolitan genus of the family Trichogrammatidae that comprise egg parasitoids of coleopteran, hemipteran, lepidopteran and thysanopteran insects, are reviewed. Oligosita xinyangensis sp. nov.(Hymenoptera, Trichogrammatidae) is described in detail and illustrated;the male of O. nigroflagellaris Lin is reported for the first time. New distributional data are provided for O. japonica Yashiro, O. mediterranea Nowicki, O. pallida Kryger, O. polioptera Lin and O. shibuyae Ishii from China, and a key to all the Chinese species of the genus is given.