The potential of periphyton-based culture of two Indian major carps, rohu Labeo rohita (Hamilton) and gonia Labeo gonius (Linnaeus)

The effects of periphyton, grown on bamboo substrates, on growth and production of two Indian major carps, rohu, Labeo rohita (Hamilton) and gonia, Labeo gonius (Linnaeus), were studied at the Bangladesh Agricultural University, Mymensingh. For each species, five ponds were provided with bamboo substrates and five ponds without substrate (control). Ponds were stocked at a rate of 10 000 ha^?1 in both treatments. There was no discernible difference in water quality parameters between treatments. A large number of plankton (39 genera) showed periphytic nature and colonized the bamboo substrates. Rohu grew faster, resulting in a 77% higher net production (P < 0.05) in the ponds with bamboo substrates compared with the ponds without substrate. In contrast, the growth and production of gonia did not vary significantly (P > 0.05) between the substrate and control ponds. Rohu seems to be a more suitable candidate for periphyton‐based aquaculture systems than gonia.     

聚苯胺/竹炭复合材料的制备及性能研究

利用竹炭(BC)的导电性和特殊的多孔结构,结合聚苯胺(PANI)的导电性,通过原位溶液聚合法制备了具有导电性能的聚苯胺/竹炭(PANI/BC)复合材料,考察了各种反应条件对复合材料电导率的影响.利用四探针、红外光谱、扫描电镜对复合材料的导电性能、分子结构、微观形貌进行表征测试.结果表明:当苯胺用量为1mL,引发剂过硫酸...     

Estimating state-wide biomass carbon stocks for a REDD plan in Acre, Brazil

As in many other developing countries, the state government of Acre, Brazil, is developing a program for compensating forest holders (such as communities of rubber tappers and indigenous peoples as well as small, medium and large private land holders) reducing their emission of atmospheric heat-trapping gases by not deforesting. We describe and then apply to Acre a method for estimating carbon stocks by land cover type. We then compare the results of our simple method, which is based on vegetation mapping and ground-based samples, with other more technically demanding methods based on remote sensing. We estimated total biomass carbon stocks by multiplying the measured above-ground biomass of trees >10 cm DBH in each of 18 forest types and published estimates for non-forest areas, as determined by measurement of 44 plots throughout the state (ranging from 1 to 10 ha each), by land-cover area estimated using a geographical information system. State-wide, we estimated average above-ground biomass in forested areas to be 246 ± 90 Mg ha⁻¹; dense forest showed highest (322 ± 20 Mg ha⁻¹) and oligotrophic dwarf forest (campinarana) the lowest biomass (20 ± 30 Mg ha⁻¹). The two most widespread forest types in Acre, open canopy forests dominated by either palms and bamboo (for which ground-based data are scant), support an estimated 246 ± 44 and 224 ± 50 Mg ha⁻¹ of above-ground biomass, respectively. We calculate the total above-ground biomass of the 163,000 km² State of Acre to be 3.6 ± 0.8 Pg (non-forest biomass included). This estimate is very similar to two others generated using much more technologically demanding methods, but all three methods, regardless of sophistication, suffer from lack of field data.     

四川雅安地区2种大型丛生竹耐低温能力

以慈竹和撑绿杂交竹为材料,对四川雅安地区不同海拔2竹种叶片进行净光合速率测定,并对采取的竹叶的POD活性、可溶性蛋白和可溶性糖含量、MDA含量、脯氨酸含量以及光合色素进行测定和分析,目的在于探讨慈竹和撑绿杂交竹耐低温的生理机制.结果表明,海拔对慈竹和撑绿杂交竹的POD酶活性、可溶性蛋白含量、脯氨酸含量和可溶性糖含量的影响较大,对MDA含量影响不大.低海拔时,撑绿杂交竹具有高的可溶性蛋白含量和脯氨酸含量,慈竹的POD酶活性和可溶性糖含量很高.高海拔时,慈竹的POD酶活性、可溶性蛋白含量、脯氨酸含量和可溶性糖含量都比撑绿杂交竹高,且差异都达到极显著水平,这可能是慈竹净光合速率极显著高于撑绿杂交竹的一个原因,其中可溶性蛋白含量和脯氨酸含量对慈竹具有高净光合速率可能起到很大调节作用.低海拔慈竹和撑绿杂交竹的净光合速率无明显差异,而高海拔慈竹的净光合速率却远高于撑绿杂交竹.慈竹在高海拔的适应性比撑绿杂交竹的强,撑绿杂交竹不适宜在高海拔栽培.     

丛生竹生长特性及管理技术研究进展

丛生竹生长特性是丛生竹林结构调整和林地管理的依据.当前有关丛生竹生长特性和经营技术的研究取得了较大进展,该文对丛生竹种群基株、分株克隆生长特性进行概述,并对基于丛立竹数与根盘面积比的丛生竹林分结构调整、丛生竹散生化栽培、林地管理等技术进行了总结.指出了丛生竹发展过程中还存在着可利用的丛生竹种较少、优良丛生竹种资源扩展缓慢、丛生竹生长特性与经营管理技术互动关系研究缺乏等问题,在今后应加强研究.     

丛生竹秆基各笋目的出笋成竹生物学特性研究

调查了西南地区人工栽培的梁山慈竹、撑绿竹、硬头黄竹着生于秆基两侧的4对大型芽(又叫笋目、芽眼、芽目)的出笋成竹生物学特性,计算各年龄母竹和各笋目位置的出笋率、成竹率、新竹相对生长率。结果表明:随着母竹年龄的增加,出笋成竹能力明显下降,1年生母竹出笋成竹能力最强,2年生母竹迅速下降,3年生母竹基本丧失繁殖能力;各笋目的出笋成竹能力为2目＞头目＞3目＞4目,3目、4目显著低于头目、2目。综合分析母竹年龄和笋目位置表明:1年生母竹的头目、2目萌发力最强,是留笋长竹的最佳笋芽。通过有序样本聚类分析,将3个竹种的出笋期划分为初期、盛期和末期,初期出笋数少但成竹率高,中后期出笋数增加,但成竹率却明显下降;笋目萌发年龄和出笋时间与笋目位置有关,分布在秆基中下部的头目、2目萌发年龄较早,在出笋期的出笋时间也较早,而位于秆基中上部的3目、4目萌发年龄较迟,出笋时间也较晚。根据各笋目的出笋成竹特性,从抚育、间伐和水肥管理等方面提出了调控林分出笋的经营管理对策。     

浸胶量对纤维化竹单板层积材物理力学性能的影响

利用慈竹(Bamb～distegia)制备纤维化竹单板层积材,分析浸胶量时板材力学性能和耐水性能的影响.试验结果表明:随着浸胶量的增加,板材的弯曲强度和抗拉强度降低,弯曲模量和抗压强度的变化不明显,耐水性能增强,水平剪切强度提高.因此,可通过控制浸胶量,进行板材性能的设计,以适应不同用途的需求.     

毛竹蒲头电动粉碎机研发及应用初报

针对毛竹生产中存在的实际问题,研制开发了毛竹蒲头电动粉碎机,并进行了试验与应用。结果表明,设计技术路线正确,机械安全、可靠、简便、实用,生产效率大大提高。该机械的应用具有很高的经济效益和生态效益。综合分析了机械的应用效果,并对林业机械的开发提出建议。     

河南博爱县竹竿锈病的分布与防治策略

河南博爱竹林是中原地区宝贵的竹资源。近年来,博爱县优良乡土竹种——甜竹受到了竹竿锈病的严重危害。文章调查了竹竿锈病的分布状况,提出了以营林措施为主,药剂防治为辅,协调运用人工、物理等方法的综合防治措施。     

干旱冬季喷灌对毛竹冬笋生长影响试验

在干旱冬季,通过对毛竹基地进行不同喷灌处理对比试验表明,水分对冬笋生长影响明显,主要通过影响冬笋的个体形状、个体单重和个体数量等几个方面上,影响着冬笋的质量和产量。在干旱冬季进行合理喷灌,能有效地增加冬笋产量,提高冬笋质量,从而提高竹林的经营效益。