不同套种模式对产前期油茶树体生长的影响

为寻求产前期油茶最佳套种模式,促进油茶快速生长,进行了山稻、玉米、大豆、花生、辣椒五种经济作物的套种试验,并对油茶的生长指标进行测定和分析的结果表明:采用林下套种均能有效促进产前期油茶树体的生长,其影响顺序分别为山稻>花生>大豆>辣椒>玉米,建议推广产前期油茶套种山稻模式。     

油茶-花生间作土壤酶活性与养分的关系

本研究比较了丘陵地区油茶单作、花生单作及油茶-花生间作三种种植模式下五种土壤酶(蔗糖酶、蛋白酶、脲酶、酸性磷酸酶、过氧化氢酶)活性的差异,并采用相关分析、通径分析对土壤酶活性和土壤养分的相关性进行了研究,旨在探讨油茶种植模式对土壤酶活性的影响,以期为油茶生产中培肥和改良土壤提供参考。结果表明,不同种植模式对土壤酶活性影响明显。与油茶单作相比,油茶-花生间作显著提高0~10 cm土层土壤蔗糖酶、蛋白酶、脲酶及过氧化氢酶的活性,以及10~20 cm土层蔗糖酶活性;与花生单作相比,油茶-花生间作显著提高了0~10 cm土层土壤蛋白酶活性。相关性分析表明土壤酶活性与土壤养分的相关性较高,特别是脲酶和酸性磷酸酶。通径分析结果表明,土壤速效磷和速效钾对蔗糖酶产生显著的直接影响,有机质和速效磷是影响蛋白酶的主导因子,土壤全氮是影响脲酶的重要因素,土壤全氮和速效磷是直接影响酸性磷酸酶的重要因子。综合看来,与油茶单作相比,油茶-花生间作模式可以改善土壤质量,提高土壤酶活性,对提高土壤肥力有着重要意义。     

不同混农模式对产前期油茶闽43~#、48~#、60~#优良无性系幼树营养生长的影响

在田间采用两向分组的实验设计方法,研究了不同混农模式对龙海市产前期油茶闽43~#、48~#、60~#优良无性系幼树树体营养生长的影响,通过对产前期油茶林地进行连续3年不同混农套种模式的试验研究和统计分析,结果表明:参试的油茶闽43~#、48~#、60~#3个优良无性系品种之间造林成活率及幼树树体营养生长(树高、地径、冠幅平均直径)无显著差异。而混农套种模式与CK相比,混农套种的造林成活率略有下降,但影响不显著;但对油茶闽43~#、48~#、60~#优良无性系的树高、地径、冠幅平均直径的影响达极显著水平,说明混农模式是油茶幼树树体营养早日建成的关键因素之一。混农套种模式可极显著地提高产前期油茶闽43~#、48~#、60~#优良无性系幼树树体营养生长;同时产前期油茶林混农模式提高了土地利用率、增加了经济收益,达到了以耕代抚、以短养长的目的,其中以产前期油茶林+花生的混农模式效果最佳,比未混农套种的产前期油茶幼林树高生长提高了47.9%、地径生长提高了33.3%、冠幅平均直径提高42.9%、年平均经济纯收入增加2437.5元/hm2,可以在油茶产区的产前期油茶林地推广应用。     

油茶间套种技术研究

指出了间套种技术是立体复合栽培经营模式之一,通过充分利用水、肥、光、热等资源,以间套作短期作物提高土地利用效率,增加经济效益。同时,还可改良油茶林地土壤结构,有效改善小气候环境,加快幼林期生长速度,对解决林地和农业用地矛盾、提高自然资源利用率、增加林农收入具有重要意义。基于此,综述了油茶间套种技术的作用机理及其影响因素、间套种模式及其应用综合效益等,并对油茶间套种技术提出了科学合理的发展建议。     

油茶幼林套种山稻管理技术及效益分析

<正>江西省赣州市现有油茶面积243万亩,近年来新造林面积约达60万亩,但长期以来,油茶均是按传统的、单一的纯林栽培模式经营,导致土地利用率不高,林地油茶综合效益不高,严重制约了油茶产业的发展。近年来正逢我国油茶产业化发展的巨大浪潮,各地也在积极探索通过油茶立体经营栽培模式,充分利用地力,挖掘潜力,使油茶生产向深度和广度发展。油茶立体经营栽培模式主要包括有套种、间种、养殖等方面。油茶林通过合理套种、间种、养殖     

不同间作模式对油茶幼林树体生长的影响

为寻求油茶幼林林下经济作物高效间作模式,对花生、大豆、黄菊这3种经济作物进行油茶幼林林下间种试验,并对油茶幼树树体生长指标进行测定分析。结果表明:采用油茶幼林林下间种均能有效促进油茶幼树树体的生长,其影响顺序分别为间种花生间种黄菊间种大豆,建议推广油茶幼林间种花生模式。     

间种对油茶幼林生长的影响及效益分析

选用黄豆、花生、红薯和烟叶4种农作物于油茶幼林内进行间作,研究不同间种模式对油茶幼树树体生长的影响,并对间种不同经济作物的油茶幼林林地经济效益进行分析。结果表明:间种可促进油茶幼林的生长,其中间种黄豆效果最好,树高增加了0.11 m,地径增加了0.04 cm,冠幅增加了0.21 m~2,花芽数增加了20个/枝。间种可增加油茶幼林的经济效益,其中间种烟叶效益最高,经济产出为48 960元/hm~2。综合来看,油茶幼林间种的经济作物宜选择较矮小、具根瘤固氮菌的花生、黄豆。     

文成县油茶林下套种山稻技术初探

为突破油茶产业发展瓶颈,解决前期资金投入大、经济效益见效慢的问题,探索了研究油茶林下套种山稻的油粮套种模式,实现生态经济共赢。总结了从播种、除草、病虫兽害预防、采收等方面油茶幼林套种山稻关键技术并提出相应建议。     

不同间作模式对油茶幼林生长的影响

对不同间种模式(间种黄豆、西瓜、花生、松苗和不间种)油茶幼林的生长量情况进行分析比较得出,油茶新造林以间作花生和松苗较好,但是有间作植物的油茶林的成活率及生长量均低于未间作的油茶纯林。     

油茶幼林套种黄花菜效果分析

比较油茶幼林套种黄花菜和油茶纯林栽培的生长结实和投入产出差异,结果表明,在其他经营措施一致的情况下,油茶套种黄花菜4a后树高、地径、冠幅、分枝数和单株结果数均高于纯林,其中树高、地径、单株结果数分别达到1.66m、3.52cm、142个,增加了9.89%、14.66%和33.96%,显著促进油茶生长结实差异。套种黄花菜,可收获花、花粉和根等产品,不仅经济效益好,且生态价值高,是适宜丘陵红壤地发展的油茶幼林套种的良好生态栽培模式。     

Influence of different Taxodium ascendens stands on the open ranges and system performance in Jiangsu Province, China

This paper reveals the results of an eight-year experiment set up to identify the effects of four tree spacing configurations (1.5 × 4 m, 1.2 × 5 m, 2 × 3 m and 1.5 × 2 × 6 m) on open ranges and the relationship between open ranges and species coexistence in Taxodium ascendens-intercrop systems. Relative interrow open ranges and relative interplant open ranges were significantly different among four tree spacings. All relative open ranges (relative interrow open ranges, relative interplant open ranges, relative canopy open ranges and relative space-volumed open ranges) decreased with increasing age. The wider interrow or interplant spacings of trees offered wider (relative) interrow or interplant open ranges for intercrops. All of the tree spacings, except spacing 2 × 3 m, had negative relative interplant open ranges in nine-year-old stands, suggesting that the canopies between a plant and its neighbouring plant were in direct competition, and no interplant open range existed between two individual trees. Up to age nine, spacing 1.5 × 2 × 6 m showed no marked disadvantage in growth performance as compared to the other three spacings, but provided wider interrow open ranges for intercrops. Starting with tree stands of age four years, the yields of interplanted wheat (Triticum aestivum), soybean (Glyciae max) and rape (Brassica napus) decreased significantly as a result of the decrease of open ranges in tree stands. The yields of wheat, soybean and rape were lower in tree spacing 2 × 3 m than in other spacings. There was a positive correlation between wheat yields and canopy open ranges. This revised version was published online in June 2006 with corrections to the Cover Date.     

幼树不同直径对立木材积和生物量解释能力研究

利用马尾松幼树的样木实测数据,分析不同直径与立木材积和生物量模型确定系数之间的关系.结果表明:不同高度处直径对材积和生物量变动的解释能力并没有显著差异,但相对而言胸径的解释能力一般都要好于地径;对于材积模型而言,胸径仍是最合适的解释变量,而对于生物量的解释,0.5 m处直径可能比胸径更合适.     

Models for predicting height and diameter of individual trees in young Picea abies (L) karst. stands

Models for predicting height and diameter of individual trees in young Picea abies (L.) Karst. stands were developed. Data collected in a large survey of young forest stands in Sweden (the HUGIN young stand survey) were used in the construction of the models. Models were developed both with and without competition indices included. When constructing the competition indices trees within three metres from the subject tree were regarded as competitors. Functions with competition indices included (distance dependent) will be useful in analyses of the development of stands with different stand structure, whereas functions without competition indices (distance independent) will be useful in systems for long‐term forecasts of yield.     

Snag longevity of Douglas-fir,western hemlock,and western redcedar from permanent sample plots in coastal British Columbia

Snags are important both as structural components and as animal habitat in forests, but abundance is often low and their dynamics poorly understood in young, managed stands. Using a large data set of 19,622 snags from permanent plots in second-growth forests of coastal British Columbia, we modeled snag longevity (time from tree mortality to snag fall) for three species: Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), and western redcedar (Thuja plicata). Snag longevity was strongly related to species and snag size (diameter): the median snag longevity was 16 years for Douglas-fir, 11 years for hemlock and 5 years for redcedar. Western redcedar was predominantly in the subcanopy and its rapid fall rate was related to the small size of its snags. In addition to diameter, other attributes (height to diameter ratio, height, and live crown ratio before death) contributed significantly to models for one or two of the species. However, site level variables did not contribute significantly to any of the models. Snags greater than 50 cm diameter, especially Douglas-fir snags, have the potential for persistence well beyond 20 years in these second-growth forests, and could be important for wildlife.     

茶园套种降香黄檀效应的初步研究

根据降香黄檀和茶树的生物学、生态学特性及华安光照人林场的生态环境条件,采取林+茶栽培模式,开展了茶园不同密度套种降香黄檀试验。初步结果表明:降香黄檀造林平均成活率和保存率均达96%以上;2.5年生时,平均树高4.38m,平均地径5.16 cm,但不同坡向生长量差异极显著;降香黄檀抗冻能力强,表现出较好的适应性和速生性。套种密度为450~600株.hm-2比较适宜,不仅改善了茶园的生态环境,提高了茶叶产量和品质,而且使茶园的经济效益显著提高。     

马尾松天然次生林间伐效应研究

于平均年龄为23年生、地位指数为14和12的2种立地的马尾松天然次生林中,分别设置固定标准样地,并分别设计5个和6个密度水平,对其抚育间伐4年后的间伐效应进行研究。结果表明:不同地位指数的林分,其间伐前或间伐后立木径级分布均呈现正态分布的规律;间伐前林分分化强烈,立木径级大小悬殊;间伐后林分最小株距和平均株距较接近,大径级林木比例提高;间伐4年后平均径级左右的立木比例明显增加。间伐4年后,当14地位指数林分的密度大于1 500株/hm2,12地位指数林分的密度大于1 950株/hm2时,其胸径离散度较间伐当年间伐后的反而明显增大;平均胸径和单株材积的增长均随保留密度的加大而减小,但单位面积蓄积量增长则在其适宜密度时最大;不同保留密度各处理间平均胸径、单株材积以及单位面积材积增长的差异均达极显著,但树高和比重增长的差异均不显著;间伐各处理的平均胸径、单株材积以及单位面积材积增长均大于对照;14地位指数马尾松林以保留密度为1 500/hm2处理的单位面积材积增长最大,增长30.29%;12地位指数马尾松林以保留密度为1 950/hm2处理的单位面积材积增长最大,增长24.38%。     

Effect of Betula pendula Admixture on Tree Growth and Branch Diameter in young Pinus sylvestris Stands in Southern Finland

The effects of a birch admixture on the height and diameter growth and maximum branch diameter in planted Scots pine stands was studied using models constructed with a data set from 13 stands of 9–16 yrs of age and 2–8 m dominant height on average sites on mineral soils in southern Finland. The density and height of the birch varied highly between and within stands. Simulated results indicated that the pines were capable of keeping up in height growth with birches that had originated from seed. Even a very high number of birches (10?000 stems ha^?1) had virtually no effect on the height growth of the pines. The number of birches had a pronounced effect on the diameter growth and the maximum branch diameter in pine. Retention of a temporary birch component in young pine stands seems a feasible way of mitigating the adverse effects of low planting densities on the external quality of pine.     

广东省针阔混交林直径分布规律研究

基于2012年广东省森林资源连续清查样地和样木调查数据,分析广东省针阔混交林直径分布特征,应用Weibull分布函数分别按全林分、不同起源、不同龄组和不同林分密度对省域尺度的针阔混交林林木直径分布进行了拟合和卡方检验。结果表明,在SPSS和Matlab软件中拟合出的15个模型中有10个能够较好地由Weibull分布函数模拟,多模型较好地表达了起源、龄组、林分密度等主要林分因子的针阔混交林林木直径分布。但纯天然起源、人工植苗、幼龄林、中龄林、林分密度为1 000~1 500株/hm2和2 000~3 000株/hm2的针阔混交林林木直径分布模型因受人为干扰,Weibull拟合效果不理想,需进一步尝试其它抗干扰模型。     

Do individual-tree growth models correctly represent height:diameter ratios of Norway spruce and Scots pine?

Height:diameter ratios are an important measure of stand stability. Because of the importance of height:diameter ratios for forest management, individual-tree growth models should correctly depict height:diameter ratios. In particular, (i) height:diameter ratios should not exceed that of very dense stands, (ii) height:diameter ratios should not fall below that of open-grown trees, (iii) height:diameter ratios should decrease with increasing spacing, (iv) height:diameter ratios for suppressed trees should be higher than ratios for dominant trees. We evaluated the prediction of height:diameter ratios by running four commonly used individual-tree growth models in central Europe: BWIN, Moses, Silva and Prognaus. They represent different subtypes of individual-tree growth models, namely models with and without an explicit growth potential and models that are either distance-dependent (spatial) or distance-independent (non-spatial). Note that none of these simulators predict height:diameter ratios directly. We began by building a generic simulator that contained the relevant equations for diameter increment, height increment, and crown size for each of the four simulators. The relevant measures of competition, site characteristics, and stand statistics were also coded. The advantage of this simulator was that it ensured that no additional constraint was being imposed on the growth equations, and that initial conditions were identical. We then simulated growth for a 15- and 30-year period for Austrian permanent research plots in Arnoldstein and in Litschau, which represent stands at different age-classes and densities. We also simulated growth of open-grown trees and compared the results to the literature. We found that the general pattern of height:diameter ratios was correctly predicted by all four individual-tree growth models, with height:diameter ratios above that of open-grown trees and below that of very dense stands. All models showed a decrease of height:diameter ratios with age and an increase with stand density. Also, the height:diameter ratios of dominant trees were always lower than that of mean trees. Although in some cases the observed and predicted height:diameter ratios matched well, there were cases where discrepancies between observed and predicted height:diameter ratios would be unacceptable for practical management predictions.