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《江苏林业科技》2015,(5)
以7年生‘奥斯特’北美冬青为试验材料,测定叶片中N,P,K,Ca,Mg,Mn,Fe,Zn,Cu,B元素含量,分析叶片主要营养元素年动态变化规律,为树体营养诊断和合理施肥提供科学依据。结果表明:(1)叶片中营养元素含量高低为NKPCaMnMgZnFeBCu;(2)随着时间推移,叶片中各营养元素年动态变化出现规律性波动,其中N,P,K,Cu含量总体呈下降趋势,Ca,Mg,Mn,Fe,Zn,B含量总体呈上升趋势。初步认为:N,P,K,Ca,Mg,Zn,Fe,Cu元素营养诊断可在8月7日到8月26日期间进行,Mn,B元素可提前至6月26日到7月16日期间进行。 相似文献
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枫香播种育苗及造林技术 总被引：1，自引：0，他引：1
枫香(liquibambar formosana)别名枫树,路路通,金缕梅科枫香属,落叶乔木,枫香树干道直,树冠广卵型,秋叶红艳,是著名红叶树种,喜光,略耐阴,喜温暖湿润气候;具深根性,适应性强,适生于深厚肥活的酸性至中性土壤,略耐旱,速生,萌芽力强,其木材纹理细致,色泽鲜明,抗压耐腐,枝桠等可作香姑木耳原料,根皮可入药,落叶易分解腐烂,改善生态环境和提高土壤肥力。因此,枫香是集用材、观赏于一身的优良乡土树种,枫香主要分布在秦岭及淮河以南各地。1育苗1.1圃地概况我场位于皖东明光市境内,气候温和,雨量适中,日照充足,四季分明,夏热多雨,冬寒干燥,年平均… 相似文献
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阐述龙岩市百香果主要病虫害及其症状特征,主要病害由重到轻依次为病毒病,疫病,褐斑病,炭疽病,煤烟病,茎基腐病,灰霉病,立枯病等;主要虫害依次是蓟马,实蝇,蚜虫,介壳虫,地老虎,红头芫菁,红蜘蛛,蛴螬等,并提出相关预防措施建议. 相似文献
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1IntroductionABA(abscisicacid),oneofthegenerallyaccepted5phytohormones,regulatesmanyagronomicallyimportantcharactersofhigherplantdevelopment,includingthesynthesisofseedstorageproteinsandlipids,theenhancementofseeddesiccationtoleranceanddormancy,andtheinhibitionofthephasetransitionsfromembryonictogerminativegrowthandfromvegetativetoreproductivegrowth(Zhuetal.1997,1998,Shao2001a,b,Zhu2001,BaoandLi2002,Eckardt2002a,Finkelsteinetal.2002,GaoandLi2002,LiscumandReed2002,ShaoandLiang2002,Shaoeta… 相似文献
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P.L. Mafongoya R. Chintu T.S. Chirwa J. Matibini S. Chikale 《Agroforestry Systems》2003,59(3):279-288
Seeking an alternative to Sesbania spp. tree fallows, a Tephrosia species and provenance trial was conducted at Msekera Research Station, Chipata (Zambia) to evaluate eleven Tephrosia vogelii and three Tephrosia candida provenances. They were tested for biomass production, quality of biomass, resistance to root-knot nematodes, nitrogen release,
and for their effects on soil nitrogen dynamics. At the end of 1.5 years, the T. candida provenances 02970, 02971 and 02972 from Madagascar produced two times greater amount of aboveground biomass than the T. vogelii provenances. There was little variability among the T. vogelii provenances in terms of litter and biomass production. Weed growth was significantly greater under T. vogelii than T. candida provenances. While Tephrosia vogelii provenance 98/02 from Zambia and T. candida 02972 were highly tolerant to the Meloidogyne incognita nematodes, T. vogelii provenances 02977, 98/03, 02973 from Kenya, Zambia and Malawi, respectively, were highly susceptible to the nematodes. The
Tephrosia species and provenances showed a wide variability in terms of N, lignin and polyphenol concentration in their foliage. Mineralization
of N in the foliage of T. candida provenances 02970 and 02971 and T. vogelii provenances 98/04 and 02974 from Malawi occurred rapidly within 14 weeks of incubation. At the end of the 2-year growth period,
there was significantly greater total inorganic N under T. candida provenance 02972 (12.5 mg kg−1) than T. vogelii (5 mg kg−1) provenance Mungwi 98/02. Maize (Zea mays L.) yields after T. candida provenances were greater than those after T. vogelii provenances. Further testing of the most promising provenances is needed for their effects on subsequent maize yields under
a range of farm conditions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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The competition–density (C–D) effect for non-self-thinning Populus deltoides and Populus × euramericana plantations from 3 to 9 years was analyzed using the reciprocal equation of the C–D effect. The C–D effect was well described
by the reciprocal equation, and with the progress of time the C–D curve, on logarithmic coordinates, of the P. × euramericana plantations shifted upward faster than that of the P. deltoides plantations. With increasing physical time t, the biological time τ, i.e. the integral from zero to t of the coefficient of growth λ(t) in the general logistic curve with respect to t, increased rapidly during early growth stages and the increases in τ gradually became slow during later growth stages. This trend was more evident in the P. deltoides plantations than in the P. × euramericana plantations. The coefficients A and B included in the reciprocal equation were calculated at each growth stage. With increasing τ, the coefficient A, the reciprocal of which means the asymptote of yield (=wρ) at a given growth stage, increased abruptly to a maximum value and then tended to decrease gradually to a constant level.
On the other hand, the coefficient B, the reciprocal of which means the asymptote of mean stem volume at a given growth stage, decreased exponentially and tended
to be close to zero with increasing τ. The λ(t) decreased with increasing stand age, whereas the final yield Y(t) defined as W(t) ρ, where W(t) is the asymptote of w in the general logistic growth curve, increased gradually with increasing stand age. The differences in coefficients A, B, and λ(t) between the two species were reported. 相似文献
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选取重庆缙云山的针阔混交林、常绿阔叶林、毛竹林、灌木林4种典型林分,观测酸性降水过程中林外雨、穿透雨及干流等林内水分转换分量中的主要离子含量变化,分析林分冠层对雨水化学组成的影响,结果表明:(1)降雨中的离子当量浓度大小依次是SO42-＞Ca2+＞ NH4+＞Mg2+＞K+＞Na+＞NO3-;(2)降雨经过林冠层后pH值降低,干流的酸化程度增加最大;(3)降雨经林冠层后离子浓度明显增加(除灌木林),穿透雨中通量增加最大的阴离子和阳离子分别为SO42-(2.19×103～6.47×103 eq·hm-2)和Ca2+(1.41×103～3.39×103 eq-hm-2),离子来源主要为大气沉降和植物分泌物或淋出;(4)同一离子在不同林分的干流和穿透雨中的通量变化不同,反映出不同林分冠层的离子交换性差异.在针阔混交林中,林下降雨净淋溶量大小顺序为SO42-＞Ca2+＞ NO3-＞K+＞NH4+＞Mg2+＞ Na+;常绿阔叶林为SO42-＞ Ca2+＞ K+＞NO3-＞ NH4+＞ Mg2+ ＞Na+;毛竹林为Ca2+＞ SO42-＞ K+＞NO3-＞ NH4+＞Na+＞Mg2+;灌木林为Ca2+＞ NO3-＞ K+＞ Na+＞Mg2+＞ NH4+＞ SO42-. 相似文献
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S. Marañón-Jiménez J. Castro A.S. Kowalski P. Serrano-OrtizB.R. Reverter E.P. Sánchez-Cañete R. Zamora 《Forest Ecology and Management》2011,261(8):1436-1447
After a wildfire, the management of burnt wood may determine microclimatic conditions and microbiological activity with the potential to affect soil respiration. To experimentally analyze the effect on soil respiration, we manipulated a recently burned pine forest in a Mediterranean mountain (Sierra Nevada National and Natural Park, SE Spain). Three representative treatments of post-fire burnt wood management were established at two elevations: (1) “salvage logging” (SL), where all trees were cut, trunks removed, and branches chipped; (2) “non-intervention” (NI), leaving all burnt trees standing; and (3) “cut plus lopping” (CL), a treatment where burnt trees were felled, with the main branches lopped off, but left in situ partially covering the ground surface. Seasonal measurements were carried out over the course of two years. In addition, we performed continuous diurnal campaigns and an irrigation experiment to ascertain the roles of soil temperature and moisture in determining CO2 fluxes across treatments. Soil CO2 fluxes were highest in CL (average of 3.34 ± 0.19 μmol m−2 s−1) and the lowest in SL (2.21 ± 0.11 μmol m−2 s−1). Across seasons, basal values were registered during summer (average of 1.46 ± 0.04 μmol m−2 s−1), but increased during the humid seasons (up to 10.07 ± 1.08 μmol m−2 s−1 in spring in CL). Seasonal and treatment patterns were consistent at the two elevations (1477 and 2317 m a.s.l.), although respiration was half as high at the higher altitude.Respiration was mainly controlled by soil moisture. Watering during the summer drought boosted CO2 effluxes (up to 37 ± 6 μmol m−2 s−1 just after water addition), which then decreased to basal values as the soil dried. About 64% of CO2 emissions during the first 24 h could be attributed to the degasification of soil pores, with the rest likely related to biological processes. The patterns of CO2 effluxes under experimental watering were similar to the seasonal tendencies, with the highest pulse in CL. Temperature, however, had a weak effect on soil respiration, with Q10 values of ca. 1 across seasons and soil moisture conditions. These results represent a first step towards illustrating the effects of post-fire burnt wood management on soil respiration, and eventually carbon sequestration. 相似文献
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We investigated the temporal dynamics of large woody debris (LWD) in five headwater streams before and after the 2001 Dogrib fire in the foothills of Alberta. The density of LWD varied from 5 to 41 logs per 50 m of stream reach and accounted for 19.4 ± 5.1 m3 ha−1 (mean ± standard error) of wood in the riparian zones and 114.1 ± 30.1 m3 ha−1 of wood in the bankfull margins of the stream channel. Individual logs averaged 18.9 ± 1.15 cm in diameter, 5.5 ± 0.7 m in length, and 0.2 ± 0.02 m3 in volume. Logs became significantly shorter in decay classes II–IV. Bridges were longer than partial bridges, which were longer than loose and buried LWD. Individual log volume was greatest for bridges, but not significantly different among other position classes. Bridges and loose LWD contributed little to stream morphology and function; however, 55% of partial bridges and all buried logs contributed to sediment storage, channel armouring, or riffles and pools in the stream channel. 相似文献
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Vishal Singh Ashish TewariSatya P.S. Kushwaha Vinay K. Dadhwal 《Forest Ecology and Management》2011,261(11):1945-1949
Biomass and carbon sequestration rate of a young (four year old) mixed plantation of Dalbergia sissoo Roxb., Acacia catechu Willd., and Albizia lebbeck Benth. growing in Terai region (a level area of superabundant water) of central Himalaya was estimated. The plantation is seed sown in the rainy season of year 2004 and spread over an area of 44 ha. Allometric equations for both above and below ground components were developed for three tree species. The density of trees in the plantation was 1322 trees ha−1 The diameters of trees were below 10 cm. Five diameter classes were defined for D. sissoo and A. catechu and 3 for A. lebbeck. 5 trees were harvested in each diameter class. Individual tree allometry was exercised for developing the allometric equations relating tree component (low and above ground) biomass to d.b.h. Post analysis equations were highly significant (P > 0.001) for each component of all species. In the plantation Holoptelia integrifolia Roxb. (Family Ulmaceae) has been reduced to shrub form because of frost. Only the aboveground biomass of H. integrifolia and other shrubs were estimated by destructive harvesting method. Herbaceous forest floor biomass and leaf litter fall were also estimated. The total forest vegetation biomass was 10.86 Mg ha−1 in 2008 which increased to 19.49 Mg ha−1 in 2009. The forest is sequestering carbon at the rate of 4.32 Mg ha−1 yr−1. 相似文献
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Yousef Moradi‐Amirabad Heshmat Rahimian Valiollah Babaeizad Sandra Denman 《Forest Pathology》2019,49(4)
Decline diseases of forest trees are complex syndromes not attributable to single causal factors. In Iran, symptoms of decline disease have been observed in a number of native forest species including Quercus castaneifolia (chestnut‐leaved oak), Q. brantii (Persian oak) and Carpinus betulus (hornbeam). The symptoms are prevalent in the northern forests and the Zagros mountain forests. There are parallels between the disease in Iran and acute oak decline (AOD) reported in the UK, specifically the presence of weeping cankers, which have been attributed to a polybacterial complex wherein Brenneria goodwinii is considered a key necrogen. Based on the AOD symptomatology, and as a first step towards discovering potential causal agents of the stem weeping symptoms of affected trees in Iran, necrotic tissues were tested primarily for the presence of B. goodwinii. Symptomatic Q. castaneifolia and C. betulus from the Mazandaran Province and symptomatic Q. brantii from Kohgiluyeh and Boyerahmad Province were sampled. Isolation and culture on a selective medium yielded uniform bacterial colonies. Isolates were characterized using phenotypic and genotypic (DNA sequencing) tests. The isolates were phenotypically identical to members of Pectobacteriaceae and Yersiniaceae, specifically Brenneria and Rahnella spp. The nucleotide sequences of the 16S rRNA and housekeeping genes gyrB, infB and atpD (MLSA) amplified via PCR demonstrated that the isolates from the trees in Iran were indeed B. goodwinii, B. roseae subsp. roseae, Rahnella victoriana and an unknown species of Brenneria. Most bacteria isolated from non‐symptomatic trees were Gram‐positive, and Pseudomonas spp. were dominant, but bacterial species isolated from the diseased trees were not detected in healthy trees. Hypersensitivity response tests were positive, but inoculation on saplings was more variable with internal necrosis developing only once in the test period. Therefore, further testing is required. This is the first report of the incidence of B. goodwinii, B. roseae subsp. roseae, R. victoriana and Brenneria sp. associated with acute oak decline‐like symptoms on Q. castaneifolia, Q. brantii and C. betulus across the western forests of Iran and in the world. 相似文献
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Michael S. Watt David J. PalmerLindsay S. Bulman 《Forest Ecology and Management》2011,261(11):1792-1798
Despite being a damaging foliar disease of Pinus species little research has characterised spatial variation in disease severity of Dothistroma needle blight at a macroscale. Using an extensive dataset describing Dothistroma needle blight severity (Ssev) on plantation grown Pinus radiata stands distributed widely across New Zealand the objectives of this research were to (i) develop a regression model describing Ssev, (ii) use this model to identify key drivers of Ssev, their functional form and relative importance, and (iii) develop spatial predictions of Ssev for New Zealand P. radiata under current climate. Using an independent validation dataset, the final model accounted for 72% of the variance in Ssev using four significant (P < 0.001) explanatory variables and an isotrophic exponential model to account for the spatial covariance in the data. Ssev was most sensitive to mean air temperature from November to April (TNov-Apr), followed by mean relative humidity from October to April (RHOct-Apr), mean total November rainfall (PNov), and then stand age (A). There was a quadratic correlation between A and Ssev with Ssev increasing to a maxima at 12 years before declining. Ssev exponentially increased to a threshold with increases in both PNov and RHOct-Apr. The relationship between Ssev and TNov-Apr was quadratic with Ssev increasing to a maximum at TNov-Apr of 15.5 °C before declining at higher values of TNov-Apr. Spatial predictions of Ssev varied widely throughout New Zealand. Values of Ssev were highest in moderately warm wet environments in the North Island, and on the west coast of the South Island. In contrast, relatively low values of Ssev were predicted in drier eastern and southern regions of New Zealand. 相似文献
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Phytophthora pseudosyringae associated with the mortality of Nothofagus obliqua in a pure stand in central‐southern Chile 
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下载免费PDF全文 S. N. Fajardo S. Valenzuela A. F. Dos Santos M. P. González E. A. Sanfuentes 《Forest Pathology》2017,47(6)
Mortality of Nothofagus trees in the southern‐central Chile region has been observed for over 30 years. A field survey conducted in 2013 detected partial defoliation and bleeding cankers on Nothofagus obliqua in a pure stand in the Nahuelbuta coastal ranges of the Biobío region. A Phytophthora sp. was isolated from stem cankers and soil samples around symptomatic N. obliqua trees: All isolates were identified as Phytophthora pseudosyringae. These isolates were pathogenic on 1‐year‐old N. obliqua and Nothofagus alpina, and on detached twigs of adult N. obliqua and Nothofagus dombeyi trees. This paper is the first to report association and pathogenicity of P. pseudosyringae with N. obliqua, N. alpina and N. dombeyi native to the Biobío region of Chile. The potential of P. pseudosyringae to cause damage in natural Nothofagus stands in Chile must be determined. 相似文献
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Interest in the use of bioenergy is increasing because of the need to mitigate climate change, the increasing costs and finite supply of fossil fuels, and the declining price of lumber and paper. Sound bioenergy policies must be informed by accurate estimates of potential feedstock production, rights to the production, social values and economics. Two of the main sources of bioenergy feedstock from forests are (i) harvesting residue and (ii) dead wood resulting from natural disturbances (i.e. standing dead timber). We modeled the production of bioenergy feedstock from these two sources from 2005 to 2020 for Canada's managed forest south of 60° N so that this information can be used in provincial and national strategic planning. Published estimates of harvesting residue vary widely, and our objective was to provide more precise estimates based on new forest inventory data and regional modeling. Natural disturbances result in very large quantities of dead wood on the landscape, but estimates of future stocks and annual production have not previously been made. Our estimates included a 50% discount factor to net-down theoretically available quantities to a more realistic estimate of potential ecologically sustainable bioenergy feedstock. The total future annual production averaged 51 ± 17 Tg year−1 from natural disturbances and 20 ± 0.6 Tg year−1 from clearcut harvesting residues. Harvesting residue for the area logged varied spatially from a low of 1.0 ± 0.77 kg m−2 year−1 to a high of 6.7 ± 0.1 kg m−2 year−1. Dead wood production due to insects was forecast to peak in the Montane Cordillera of British Columbia (BC) at 16.7 Tg year−1 due to the current mountain pine beetle outbreak. Total dead wood production due to fire was highest in the western portion of the boreal forest (3.6 Tg year−1 in the Boreal Shield of Saskatchewan), in part due to the high frequency of fires in these ecosystems and the large area of western boreal forest, but the highest density production was in BC: >9 kg m−2 year−1 in the burned area. Our results showed that the dead wood stocks of 331 Tg oven-dry matter potentially available for bioenergy in 2020 are much smaller than the 3100 ± 84 Tg of dead wood stocks estimated based on ecosystem dynamics. While bioenergy use will accelerate the release of greenhouse gases compared to on-site decay, the energy is renewable and can be used as a substitute for fossil fuels. The net benefit to the atmosphere of forest bioenergy use is affected by many factors, and future research should further assess which sustainable wood-based bioenergy strategies yield the greatest net greenhouse gas benefits over the different time scales needed for post-disturbance forest recovery. 相似文献