林豆复合生态系统土壤理化性质的研究

本文对混种大豆的落叶松.大豆、水曲柳-大豆复合生态系统土壤理化性质进行研究。结果表明,在一个生长季内混种后的土壤物理性质得到了改善。落叶松.大豆与水曲柳一大豆复合生态系统的土壤容重为1.112g/cm3和1.058g/cm3均低于相对应的纯林:混种大豆后土壤总孔隙度增加。两种林-豆复合生态系统土壤有机质分别比对应纯林高1.77倍和1.09倍:落叶松一大豆复合生态系统全氮和水解氮含量分别高于落叶松纯林4.2%和53.0/%,水曲柳-大豆复合生态系统全氮和水解氮含量分别高于水曲柳纯林75.5%和3.3%:混种大豆后全磷含量降低,而有效磷含量则增加:落叶松-大豆复合生态系统全钾和有效钾比落叶松纯林高0.6%和17.5%,水曲柳-大豆复合生态系统全钾和有效钾分别比水曲柳纯林高56.4%和21.8%。图1表3参27。     

不同施肥处理对笋用红竹林土壤特性的影响

2001-2004年以笋用红竹林小区精确施肥试验为基础,结合试验区内部分长期定位观测,比较研究了不同施肥处理对笋用红竹林生态系统土壤特性的影响.试验采用有机肥、纯化肥(N、NP、NPK)、有机 化肥、不施肥(CK)6个处理.结果表明:在连续3 a持续经营条件下,笋用竹林未施肥区(CK)土壤相应的有效养分消耗最快,有机质下降8.0%,全N下降5.2%,速效P下降15.0%,单施有机肥或NP、NPK化肥配施或有机无机肥料混合施用均可增加土壤有机质含量,提高次序为有机肥 化肥处理 (24.08%) >有机肥处理 (8.49%)>化肥NPK处理 (2.28%)>化肥NP处理 (1.90%),单施N肥后土壤有机质则有所下降(-4.06%),但下降幅度不如未施肥区(-7.98%).与CK区和单施化肥区比较,有机 化肥配合施用,不但提高了土壤有效养分含量,同时增加了土壤微生物生物量,促进了土壤物质的循环,提高了竹林土壤的潜在供肥能力,有利于竹林的持续生产力的发挥.     

Nutrient cycling in two traditional Central American agroforestry systems

A preliminary nutrient cycling study quantified total and temporal nutrient inputs via litterfall and pruning residues in two agroforestry systems: (1) Coffea arabica (perennial crop)-Erythrina poeppigiana (leguminous shade tree); and (2) C. arabica-E. poeppigiana-Cordia alliodora with emphasis on the effect of the timber tree C. alliodora. The total annual input of litterfall plus pruning residues was similar in both associations. Total annual input from E. poeppigiana was less than half in the association with C. alliodora than without, but the litterfall from this latter species compensated for the loss. Large differences in the total annual nutrient input of K, Ca and Mg was found between associations, but not for N or P. The amount of nutrients recycled by the associated trees reached the recommended level of fertilizer required for coffee production. The inclusion of C. alliodora within the C. arabica-E. poeppigiana association resulted in a more evenly distributed annual nutrient input.     

星天牛行为及控制技术研究Ⅰ.天牛行为及危害木麻黄规律的研究

通过野外调查和室内外人工饲养,结果表明星天牛[Anoplophorachinensis(Forster)]成虫大多在白天活动,在自然条件下有趋向木麻黄防护林带飞翔的行为。雌、雄成虫一生可多次交尾,每天8时和16时为交尾高峰。成虫补充营养最喜欢取食苦楝树(MeliaazedarachL.)。苦楝树饲养雌虫每头产卵156～198粒,平均176 4粒,是木麻黄饲养的3 10倍;取食苦楝树的雌虫寿命72～110d,平均91 8d;雄虫寿命88～125d,平均103d,雌、雄成虫分别比取食木麻黄(Casuarinaequi setifolia)的多存活30 2d、40d。幼虫主要集中在离地面40cm高度内的树干根际附近,占总虫数的94 8%。1年生林分受害株至第2年5月成虫羽化期死亡率最高,达66 7%,3～7年生林分有虫株率最高;7年生以下林分应重点防治。在生境条件相似的同龄林中,星天牛则喜欢危害基径较大的木麻黄,6cm以下的树则较少受害。     

油松容器苗施肥的研究

本文根据研究结果论述了油松容器苗营养土中掺合尿素的最适量,一定出圃规格油松容器苗的施肥量以及施肥量的计算方法。同时还论述了1年生油松容器苗有关的化学营养诊断指标。     

Effects of NaCl stress on seed germination, leaf gas exchange and seedling growth of Pteroceltis tatarinowii

Effects of NaCl on seed germination, leaf gas exchange and seedling growth were investigated. The germination of P. tatarinowii seeds was delayed in the presence of NaCl, and was significantly inhibited when NaCl concentration exceeded 17 mM (1.0 g·L⁻¹). NaCl treatments induced reductions of transpiration rate, stomatal conductance and net photosynthetic rate and their reductions were significant with the increasing of NaCl concentration. However, intercellular CO₂ concentration in seedling leaves under salt stress was significantly higher than that of controls. There was a significant reduction in survival, basal diameter increment and height increment with increasing NaCl concentration 50 days after NaCl treatment, and a significant reduction in the dry weight increment of roots, stems, and leaves was also observed in the NaCl treatments. The deleterious effect on the biomass increment was more evident in the case of stems and leaves. Results from this study suggest that P. tatarinowii is sensitive to salinity stress and the salinity threshold for seedling growth might be less 34 mM (2.0 g·L⁻¹). Biography: FANG Sheng-zuo (1963–), male, Professor, College of Forest Resources and Environment, Nanjing Forestry University, Nanjing 210037, P. R. China.     

高节竹与毛竹鞭笋品质和适口性比较

高节竹是优良的笋材兼用竹种, 竹鞭延伸生长能力强, 具有较高的鞭笋生产潜力。为评价高节竹鞭笋品质和适口性, 以毛竹鞭笋为对照, 比较两者外观形态和营养物质、呈味物质含量的差异。结果表明:与毛竹鞭笋相比, 高节竹鞭笋略长, 个体质量、基径和蛋白质、纤维素、木质素、单宁、草酸、总酸含量明显较低, 而可食率、糖酸比和脂肪、可溶性糖含量明显较高。高节竹、毛竹鞭笋除鲜味氨基酸含量差异不明显外, 高节竹鞭笋的氨基酸总量及其它氨基酸组分的含量显著低于毛竹鞭笋, 但鲜味氨基酸、甜味氨基酸和芳香类氨基酸组分比例显著高于毛竹鞭笋, 苦味氨基酸组分比例明显低于毛竹鞭笋。研究表明, 高节竹鞭笋较为粗大、可食率高、粗糙度低、适口性好, 质量总体优于毛竹鞭笋。     

Nutrient Management for Eucalypt Plantations in South China

Eucalypts are very popular for revegetation in many parts of south China because of their capacity to tolerate degraded sites and unfertile soils,and their fast growth potential to coppice. This paper reviews a decade of field trials in china, undertaken as part of several bilateral researchprograms in plantation forestry, concerning the use of fertilizers, harvest residue management and inoculation with ectomycorrhizal fungi. One of the key questions addressed is whether the productivity of plantation eucalypts in south China can be increased to the world average by nutrient management across a rotation.     

Vesicular-arbuscular mycorrhiza effects on Gliricidia sepium and Senna siamea in a fallowed alley cropping system

Nitrogen fixing and non-N₂ fixing legumes such as Gliricidia speium and Senna siamea have been used in alley cropping systems for soil improvement and source of N for food crops. However their establishments could be limited by P and moisture deficiencies in degraded soils. Vesicular-arbuscular mycorrhizal fungi can help to overcome these deficiencies. We examined the effects of a vesicular-arbuscular mycorrhizal (VAM) fungus, Glomus deserticola, on the performance of sole hedgerow trees of Gliricidia sepium and Senna siamea and their mixtures (interplanted) in a fallowed alley cropping experiment on a degraded Alfisol in southwestern Nigeria. Percentage root infection by VAM fungi was higher in inoculated plants than in uninoculated ones irrespective of whether they were interplanted or non-interplanted. Inoculation with G. deserticola increased dry matter accumulation and nutrient uptake (N. P, Mg and K) but there was no significant interaction between mycorrhizal inoculation and interplanting for growth and nutrient uptake except for the uptake of P, Mg and K in G. sepium. Inoculation with G. deserticola reduced leaf shedding of G. sepium by 50% but did not have the same effect for S. siamea. For both tree species inoculated plants extracted more water from 0–30 cm depth than the uninoculated ones.     

尾叶桉幼林地上部分生物量及养分循环的研究*

论述了２－３年生尾叶桉幼林地上部分生长、生物量积累和生物量在树木各器官及各径阶中的分配，林分净生产量，树木各器官及凋落物的养分含量和林分的养分循环。２年生时林分的生物量为２２．９ｔ／ｈｍ＾２，其中干材占６０．２％，皮占８．９％，枝占１４．７％，叶占１６．２％。３年生时林分生物量为４０ｔｈｍ＾２，其中干材占６３．６％，皮占７．７％，枝占１４．１％，叶占１４．６％。年净生产量为２０．５ｔ／ｈｍ＾２，约