Identification and mode of action of quantitative trait loci affecting seedling height and leaf area in Eucalyptus nitens

 Regions of the genome influencing height and leaf area in seedlings of a three-generation outbred pedigree of Eucalyptus nitens have been identified. Three QTLs affecting height and two QTLs affecting leaf area were located using single-factor analysis of variance. The three QTLs affecting height each explained between 10.3 and 14.7% of the phenotypic variance, while the two QTLs for leaf area each explained between 9.8 and 11.6% of the phenotypic variation. Analysis of fully informative marker loci linked to the QTLs enabled the mode of action of the QTLs to be investigated. For three loci the QTL effect segregated from only one parent, while for two loci the QTL showed multiple alleles and the effect segregated from both parents in the pedigree. The two QTLs affecting leaf area were located in the same regions as two of the QTLs affecting height. Analysis of these regions with fully informative markers showed that both QTLs were linked to the same markers, but one had a similar size of effects and a similar mode of action for both height and leaf area, whilst the other showed a different mode of action for the two traits. These regions may contain two closely linked genes or may involve a single gene with a pleiotrophic effect on both height and leaf area. The QTL with the greatest effect showed multiple alleles and an intra-locus interaction that reduced the size of the effect. Assessment for two of the QTLs in a second related family did not show an effect associated with the marker loci; however, this was consistent with the mode of action of these QTLs and the pattern of inheritance in the second family. Received: 1 August 1996 / Accepted: 25 October 1996     

Ant Diversity and Abundance along an Elevational Gradient in the Philippines1

Ant communities were surveyed along an elevational gradient in the Philippines extending from lowland dipterocarp forest (250 m elevation) to mossy forest (1750 m). Standardized pitfall trapping in arboreal and terrestrial microhabitats at seven sites yielded 51 species. Collecting by hand at five of the sites yielded 48 species. The two methods produced substantially different assemblages, with only 22 species (29%) taken in common. Only a fraction of the total ant community appeared to be sampled at most of the sites. Measures of species richness and relative abundance peaked at mid-elevations and declined sharply with increasing elevation. Ants were extremely rare above 1500 m elevation. Arboreal ants were trapped much less frequently than terrestrial ants at all sites. Ant species that were abundant had broader elevational distributions than those that were less common, but most species were rare and occurred at only one or two sites. The elevational patterns for ants are largely the inverse of those documented for Philippine small mammals which reach their greatest diversity and abundance at high elevations where ants are rare. This suggests that the two groups may interact competitively. Some of the patterns observed or inferred from this study may apply to tropical ant communities in general, and are presented as series of testable hypotheses as a guide and stimulus for future research.     

成年龙眼园平衡施肥示范试验

示范试验结果表明,成年龙眼的平衡施肥对提高土壤肥力、保持树体适宜营养水平以及增加果实产量有明显作用,从而证实平衡施肥方案的可行性。作者推荐,闽南丘陵地成年龙眼园的年施肥方案（667m2,产果1吨）：N20～25kg（有机肥的N约占年施N量的40％）;N：P2O5：K2O：CaO：MgO=1．0：0．5～0．6：1．0～1．1：0．8：0．4。     

中国亚热带高大竹类植物毛竹竹笋克隆生长的密度调节

对许多多年生克隆植物来说,大量的研究表明：当光是限制因子时,随着立地密度的不断增加,克隆分株的出生率逐渐减小、死亡率逐渐增加。本文观测了乔木状高大竹类植物毛竹竹笋的出生与存活过程,结果表明：竹笋的出生率,即每样方的出笋数,明显地随着成竹立竹度的增加而增加。更确切地说,竹笋的数量,不管是出笋数还是活笋数,都明显地随着带新叶（１龄叶）的成竹立竹度的增加而增加,而与带老叶（２龄叶）的成竹立竹度相关性不显著。并且竹笋的死亡率是非密度制约的。这可能是由于对毛竹来说,其立地总是比较开敞,而且,其竹笋的生长在很大程度上是不直接需光的。     

马尾松林叶面积指数动态变化的遥感监测研究

本文以浙江省江山市的马尾松幼龄林为试材,测定了各种马尾松林分的叶面积指数,并获取了同期的陆地卫星ＴＭ数据,分析和比较了几种常用的植被指数同林分叶面积指数的关系,总结得出利用航天遥感技术完全可以监测单层林分叶面积指数的动态变化过程,只是当林分的叶面积指数大于６．０时,其监测的灵敏度大为降低。虽然这一研究结果仍是初步的,但这一定量指标的出现,使人们更加深刻地了解到遥感技术以其宏观性强、快速客观准确反映地表森林分布的优势,具有广泛用于森林生态系统和森林质量动态监测研究的巨大潜力。     

Plant functional types and climate at the global scale

Abstract. Globally applicable sets of terrestrial plant functional types (PFTs) have been identified as a major need in the development of dynamic global vegetation models for use with global atmospheric models. Global sets of PFTs should represent the world's most important plant types; characterize them through their functional behavior; and provide complete, geographically representative coverage of the world's land areas. Three main schools of thought on PFTs have emerged: (1) a physiological focus on internal function, especially at the level of basic metabolism; (2) an ecological focus on function in relation to plant form and environmental conditions; and (3) a geophysical focus on how plant functions affect the adjacent atmosphere. A structural approach based on pheno-physiognomy permits ready identification of relatively familiar, recognizable plant types. Many of the criteria cited by other approaches also are intimately related to structure and its seasonal changes. An earlier global system of structural-functional PFTs and their climatic relations has been improved, including addition of less well-known plant types, and is briefly described. A more strictly ‘functional’ approach is proposed, in which major aspects of plant function, initially metabolism and water balance, are used to classify functional types and suggest how these are constrained by climate. Such functional considerations, however, are closely linked to structural manifestations - but also require other functional criteria for more completely functional classifications. A recent global model of potential natural vegetation types suggested ca. 15 major plant types as necessary to cover the world's main terrestrial vegetation patterns. These essential types correspond well with a first-cut set of structural types implied by metabolic considerations.     

Implementation of a hierarchical global vegetation classification in ecosystem function models

Abstract. We propose an alternative approach for the currently used biogeographic global vegetation classifications. A hierarchical vegetation classification system is proposed for consistent and routine monitoring of global vegetation. Global vegetation is first defined into six classes based on plant canopy structure and dynamics observable by remote sensing from satellites. Additional biome variability is then represented through a remote sensing derived leaf area index map, and direct climate data sets driving an ecosystem model to compute and map net primary production and evapotranspiration. Simulation results from an ecosystem function model suggest that the six canopy structure-based classes are sufficient to represent global variability in these parameters, provided the spatio-temporal variations in Leaf Area Index and climate are characterized accurately. If a bioclimatically based classification is needed for other purposes, our six class approach can be expanded to a possible 21 classes using archived climatic zones. For example, tropical, subtropical, temperate and boreal labels are defined by absolute minimum temperature. Further separation in each class is possible through changes in water availability defined by precipitation and/or soils. The resulting vegetation classes correspond to many of the existing, conventional global vegetation schemes, yet retain the measure of actual vegetation possible because remote sensing first defines the six biome classes in our classification. Vegetation classifications are no longer an end product but a source of initializing data for global ecosystem function models. Remote sensing with biosphere models directly calculates the ecological functions previously inferred from vegetation classifications, but with higher spatial and temporal accuracy.     

Tidal exchange of macrolitter between a mangrove forest and adjacent seagrass beds (Gazi Bay,Kenya)

In the present study the tidal transport of macrolitter between the mangrove forest in Gazi bay (Kenya) and the adjacent seagrass meadows in the bay was investigated, by deploying large standing nets, which extended over the entire height of the water column, in the transition zone between both ecosystems. In addition, the presence of macrolitter on the floor ofRhizophora mucronata andCeriops tagal stands was studied. The macromaterial (>2 mm) that was collected with the nets consisted of mangrove material (26%, mostly leaf material), seagrass leaves (60%) and macroalgae (14%). Transport was bidirectional, indicating shuttle movements of the litter, driven by the opposite flow direction of flood and ebb tides. Litter from the mangrove species consisted mainly of leaves from species occurring at the outer zone of the forest,i.e., Rhizophora mucronata andSonneratia alba. This finding suggests that the complex spatial structure of the forest hampers outflow of macrolitter from the more inner parts. Consequently, this material remains trapped within the forest. The dominant presence of seagrass litter in the macromaterial transported with the tidal water, and the conspicuous and persistent presence of seagrass litter in the low lying, peripheralR. mucronata plots (but not in the more elevatedC. tagal plots) suggest that the mangrove forest of Gazi bay is the recipient of carbon and nutrients from the seagrass system. It is hypothesized that the element cycling of the inner parts of the mangrove forest proceeds as that of a rather closed system, whereas element cycling in the outer parts has conspicuous reciprocal connections with the adjacent seagrass meadows.     

Ant-Gathering with Tools by Captive Tufted Capuchins (Cebus apella)

We examined ant-gathering with tools by captive tufted capuchins (Cebus apella) via two experiments. In Experiment 1, we provided groups of subjects with sticks and small branches and an apparatus that accommodated the use of tools to gather ants. In Experiment 2, we sealed the apparatus with acetate and provided the same subjects with sticks and stones. Seven of 14 subjects used sticks and leaves as probes to extract ants from the apparatus. Six of them modified probes by detaching sticks from larger branches, breaking sticks into two or more pieces, and subtracting leaves and bark. Three subjects later used a stone and stick tool-set to penetrate acetate barriers and to extract ants. These results demonstrate the use of tools by Cebus to capture moving prey and are consistent with the idea that sensorimotor skills associated with the production and use of tools in primates evolved convergently in capuchins and great apes.     

Plant regeneration from protoplasts ofCapsicum annuum L. cv. California Wonder

Plant regeneration from mesophyll protoplasts of pepper,Capsicum annuum L. cv. California Wonder has been demonstrated via shoot organogenesis. Protoplasts isolated from fully expanded leaves of 3-week-old axenic shoots when cultured in TM medium supplemented with 1 mg l ⁻¹ NAA, 1 mg l ⁻¹ 2,4-D, 0 5 mg l ⁻¹ BAP (CM 1) resulted in divisions with a frequency ranging from 20–25 %. Antioxidant ascorbic acid and polyvinylpyrrolidone (PVP) in the medium and incubation in the dark helped overcome browning of protoplasts. Microcalli and macrocalli were formed in TM medium containing 2 mg l ⁻¹ NAA and 0.5 mg l ⁻¹ BAP (CM II) and MS gelled medium containing 2 mg 1 ⁻¹ NAA and 0 5 mg 1 ⁻¹ BAP (CM III), respectively. Regeneration of plantlets was possible via caulogenesis. Microshoots, 2–5 percallus appeared on MS gelled medium enriched with 0.5 mg l ⁻¹ IAA, 2mg l ⁻¹ GA and l0mg l ⁻¹ BAP (CM IVc). Rooting of microshoots was obtained on half strength gelled medium containing 1 mg l ⁻¹ NAA and 0.5mg l ⁻¹ BAP. Protoplasts isolated from cotyledons failed to divide and degenerated eventually.