多肉植物的水培试验

通过十种多肉植物的水培试验,探索不同类型的多肉植物的耐水能力,试验表明景天科伽蓝菜属、仙人掌科丝苇属、昙花属、金琥属均适合水培,光照、温度、养分影响其生根及长势,这为多肉植物水培产业化提供依据。     

Range Expansion and Its Mechanisms in a Naturalized Bamboo Species,Phyllostachys pubescens,in Japan

Abstract

The distribution of Phyllostachys pubescens, introduced to Japan from China in 1736, has been expanding. The expansion was studied in Tanabe Town, Kyoto Pref., Central Japan. Long term expansion was traced using a topographic map, a land-use map and aerial photographs. Within the research region (21.35 km²), the number and total area of bamboo sites increased from 24 and 0.16 km² in 1953 to 174 and 3.04 km² in 1985. By contrast, the total area of tree sites decreased from 12.2 km² in 1953 to 8.5 km² in 1985. The average area of bamboo sites also increased from 0.67 ha in 1953 to 1.75 ha in 1985. The average rates of the current expansion, measured by censusing current and old culms in the front of 10 unmanaged bamboo sites, were 2.1 m yr^-1. Stand structure was detailed in a transitional area from a pure stand of P. pubescensto a mixed broadleaved forest. Stand structure was simpler in the area dominated by P. pubescens.Culms off! pubescenswere larger in the pure stand, and variations in DBH and height were smaller for the bamboo than for the trees in each sample site. P. pubescenshad a greater average crown length and higher canopy position. These traits allow P. pubescensto invade adjacent forests, form a uniform monolayer of foliage, and dominate competing vegetation. There was no evidence of seedling regeneration under the bamboo. More than two-thirds of the Japanese forest is secondary growth or young plantations of conifers, and in most of these, canopy height is lower than that of P. pubescens.The continuous area increment in bamboo from 1953 to 1985, positive current expansion rate in the front of unmanaged bamboo stands and the advantageous stand structure of bamboo suggest that the range expansion of P. pubescensin the secondary forest will continue in the future.     

武汉地区多肉植物产业发展报告

摘要：多肉植物生产周期短、附加值高,对于调整花木产业机构、促进就业增收有重要意义。但由于盲目投入和扩大生产,近年来多肉植物产业开始下滑。武汉市处于全国的中心,是九省通衢,有发达的交通网络,物流高效、便捷、成本低廉,具有发展多肉植物的便利条件。本文阐述了多肉植物产业近几年在我国发展现状,并对优势与瓶颈进行深入分析,以期为武汉地区多肉植物产业的可持续发展提供参考。【结论】：在找到新的增长点、切入点以前,武汉地区建议谨慎投入多肉行业。     

多肉花卉短叶巨象(Gasteria brevifolia)的离体繁殖和种质保存

[目的]探索控制短叶巨象增殖继代次数的方法。[方法]以短叶巨象的单芽为外植体,以MS培养基为基本培养基对其进行离体培养,进而建立短叶巨象无性繁殖体系并在低温环境下长时间保存该离体种质。[结果]接种到诱导培养基上35～40d后,外植体膨大且有愈伤组织形成;在培养基MS＋Kt3．0mg／L＋NAA0．1mg／L和MS＋Kt2．0mg／L＋NAA0．1mg／L中,从膨大的外植体外周长出了小芽。小芽接种到增殖培养基Ms＋Kt3．0mg／L＋NAA0．1mg／L和Ms＋Kt2．0mg／L＋NAA0．1mg／L中约30d后又有新的丛生芽发生。小苗接种到生根培养基上20～30d后,在培养基1／2MS＋NAA1mg／L中生根较粗、较少;在培养基1／2MS＋IBA1mg／L中生根较细、较多。冷藏4个月后的丛生芽的增殖苗及增殖效果与未经冷藏的种苗无明显差异。【结论】该研究为短叶巨象的快速商业化生产和种质保存奠定了技术基础。     

Drivers and trajectories of social and ecological change in the Karoo,South Africa§

This review article explores past, present and possible future drivers of change in Karoo social-ecological systems. Biogeographically, the Karoo comprises the arid Succulent Karoo and Nama-Karoo biomes covering significant portions of the Northern Cape, Eastern Cape and Western Cape provinces and a smaller part of the Free State. Despite the Karoo’s specific environment and spatial importance nationally (covering some 30% of South Africa), no government structures address its needs holistically. Today it is a politically and economically marginalised region; perceptions of it as a desert easily morph into perceptions of it as deserted and ripe for exploitation for the benefit of external constituencies, whether in the name of astronomy, shale-gas and uranium mining or renewable energy. To manage the Karoo better for present and future generations, it is clearly desirable for social and natural scientists to work collaboratively, yet there is relatively little interdisciplinary work to date. Against this background this review article provides an overview of social and ecological changes historically and in the present, and offers some cautious reflections concerning climate change, changing land use and governance as key drivers affecting trajectories of change into the future.     

Minimum population size and potential impact of feral and semi-feral donkeys and horses in an arid rangeland

Farmers in the northern, communally managed parts of the Succulent Karoo, an arid rangeland system in South Africa, historically used donkeys and horses for transport and ploughing. With increasing mechanisation, draught animal power has largely been replaced by machines. Yet, donkeys and horses have been maintained in the agricultural landscape in small feral and semi-feral herds. Research has shown that they compete directly with productive livestock (mostly sheep and goats) for forage resources, contributing little to the local economy. Local farmers identify the presence of feral donkeys and horses as one of the primary challenges in maintaining sustainable grazing regimes on their land. However, records of the number of animals roaming the rangelands are scarce and anecdotal. We therefore conducted a combination of aerial, ground, and social surveys to estimate the minimum population size and potential grazing impact of the donkey and horse population in two communally farmed sites in the Succulent Karoo. We show that, in the representative sites surveyed, there are at least 376 equines (274 donkeys and 102 horses), representing approximately the equivalent of 2 228 sheep and goats, and consuming ～8% of the potential grazing available for productive livestock in these areas. This could represent a significant lost opportunity cost for local farmers in the region.     

萝卜肉质根形成与膨大的生理研究

萝卜肉质根形成和膨大与其解剖构造密切相关,同时受地上部生长情况、花芽分化、植物激素种类与含量及外界环境条件(如温度、光照、水分及矿质营养等)的影响,概述了内质根形成和膨大的生理机制.     

多肉植物米邦塔仙人掌微型繁殖

用多肉植物米邦塔仙人掌优良品种的茎段作为外植体,获得再生植株,并从愈伤组织形成、芽诱导、芽增殖,到诱导生根培养,建立起完整的微型快速繁殖体系。这些工作为快速商业化生产和种质保存奠定了技术基础。     

Response of arthropod communities to plant-community rehabilitation efforts after strip mining on the semi-arid west coast of South Africa§

Strip mining in arid ecosystems causes extreme ecological destruction that may take decades to recover. The present study examined the effect of different plant-community rehabilitation treatments on arthropods after strip mining in the arid Namaqualand region of South Africa. Vegetation cover and plant species richness were significantly lower at all rehabilitated sites compared with those at a reference site. Arthropod species richness did not differ amongst the different treatments and the reference site. Except for the most recently rehabilitated site, arthropod abundance in all guilds was higher at all treatments compared with that of the reference site. Overall arthropod abundance was positively correlated to plant cover and negatively correlated to plant species richness, but these vegetation characteristics had no effect on arthropod species richness. This may be explained by a high cover of pioneer plants at the rehabilitated sites, which offer ample food for generalist arthropod taxa. Arthropod community composition differed significantly between treatments. We demonstrate that rehabilitation of ecosystem function after mining in arid systems is a lengthy process, even after implementation of intensive rehabilitation protocols. We also show that arthropod communities provide additional insights into the level of ecosystem recovery otherwise obscured when only considering plant community data.