Elsinoe takoropuku sp. nov. infects twigs of Pittosporum tenuifolium in New Zealand

Elsinoe takoropuku sp. nov. is described from Pittosporum tenuifolium Sol. ex Gaertn. (Pittosporaceae). This species causes swelling to develop on the twigs of the host species. The species initially was thought to be a recent introduction to New Zealand but, based on the host association and the geographic range of the fungus in New Zealand, it is considered to be a newly described native species.     

Climatic relationships of some New Zealand forest tree species

Abstract. A dataset of some 10 000 plots was used to describe the climatic relationships of 33 widespread New Zealand tree species. Estimates of mean annual temperature, temperature seasonality, mean annual solar radiation, and moisture balance were derived from mathematical surfaces fitted to climate station data. Plots were also categorized into five lithological classes and three drainage classes. Generalized additive models were used to examine species/environment relationships. Mean annual temperature and mean annual solar radiation are most strongly correlated with current tree distributions, followed by moisture balance, temperature seasonality, lithology, and drainage. Most broad-leaved tree species other than Nothofagus spp. reach their greatest levels of occurrence in warm, moist environments with high solar radiation. In contrast, Nothofagus spp. generally reach their greatest levels of occurrence in cooler and/or lower insolation environments, and all have lower levels of occurrence on rhyolitic substrates which have resulted from large-scale geomorphic disturbance, mostly over the past few thousand years. Although coniferous species have widely differing climatic optima, many are biased towards lithological classes characterized either by large-scale geomorphic disturbance or harsh edaphic conditions. The relevance of these results to particular synecological questions is briefly discussed. Continuing adjustments in the range of slow-dispersing Nothofagus spp. are strongly suggested, and the climatic suitability of extensive rhyolitic basins in the central North Island, from which these species are largely absent, is confirmed.     

Structure of fructans from excised leaves of New Zealand flax

The accumulation of total water-soluble carbohydrate, and specifically sucrose and fructan, by excised leaves of Phormium tenax and P. cookianum (family Phormiaceae J. G. Agardh, order Asparagales) was investigated. Total water-soluble carbohydrate content of excised leaves of P. tenax and P. cookianum increased during 48 h of continuous illumination at an average rate of 1.3 and 0.9 mg g(-1) fresh weight leaf per hour, respectively. The sucrose content of excised leaves increased throughout the experimental period. The fructan content of excised leaves of P. tenax increased slightly throughout the experimental period, whilst that of P. cookianum was variable and showed no overall change. Chemical and spectroscopic analysis of the fructans obtained from the two Phormium species showed that they were similar to each other and contained mostly 1-linked and terminal fructofuranosyl (Fruf) residues, together with smaller amounts of 6-linked Fruf, 1,6-branched Fruf, terminal and 6-linked glucopyranosyl residues. Separation of the fructans by thin-layer and high-performance anion-exchange chromatography revealed the presence of a complex mixture of fructo-oligosaccharides and higher molecular weight fructan. The branched structure of the fructans isolated from excised leaves of Phormium resembles that of fructans and fructo-oligosaccharides isolated from some related species within the order Asparagales (Agave vera cruz, Cordyline australis and Urginea maritima), but is distinct from the linear structure of fructans from others (Allium cepa and Asparagus officinalis). The structural heterogeniety of fructans within both the order Asparagales and superorder Liliiflorae may be a useful chemotaxonomic aid.     

Environmental correlates of tree alpha-diversity in New Zealand primary forests

Correlations between environment and tree alpha-diversity in New Zealand's primary forests were examined using an extensive quantitative dataset (14 540 plots). Generalised additive models were used to examine relationships between species richness and temperature, solar radiation, root-zone moisture deficit, relative humidity, lithology, drainage, and plot size for all trees (112 species), and separately for broadleaved trees (88 species), conifers (17), and the genus Nothofagus (4). Diversity both for all tree species and for broadleaved trees was predicted to be highest on sites with high temperatures, high solar radiation, and high soil and atmospheric moisture, and on sedimentary and basaltic substrates. Highest conifer diversity was predicted on sites with intermediate temperatures, low solar radiation, high root-zone and atmospheric moisture, and rhyolitic and Quaternary substrates, particularly where drainage was impeded. Highest Nothofagus diversity was predicted for sites combining low temperatures, high solar radiation, high root-zone moisture but low atmospheric moisture, and on granitic substrates. Differences in diversity between the species groups on different lithologies are interpreted as rejecting both the effects of variation in large-scale disturbance histories, and the effects of confounding environmental factors associated with particular substrates. There were also significant interactions between species groups: both broadleaved tree and conifer richness were predicted to be lower on sites where one or more Nothofagus spp. — all of which have marked patchiness in their distribution — are present. Although these results are consistent with the hypothesis that tree diversity is highest on sites conducive to high productivity, history is also indicated as an important determinant of tree diversity in New Zealand.     

Breakdown and detritivore colonisation of leaves in three New Zealand streams

Breakdown of leaves from three native riparian tree species, and their colonisation by shredding and collecting insect larvae, were investigated in three streams on Banks Peninsula, New Zealand. Leaves were introduced in baskets at the time of leaf fall. Breakdown rates of leaves were faster than previously recorded in New Zealand streams and were comparable to those of many northern hemisphere deciduous species. Shredder and total detritivore densities and biomass in leaf baskets were also greater than previously found in New Zealand streams. Peaks of shredder biomass on red beech and mahoe leaves were found when only about 20% of leaf biomass remained. No shredder peak was recorded on fuchsia leaves, and no collector peaks occurred in any of the streams. Relative shredder and collector biomass (per g DW leaf) in leaf baskets did not exceed or was smaller than in leaf litter accumulations of mixed origin and conditioning throughout the streams during leaf breakdown although absolute shredder and collector biomass (per m² stream bottom) was occasionally larger in baskets than in the rest of the stream. These findings support contentions that spatial and temporal relationships between detrital inputs and detritivore biomass and life histories are weak in New Zealand streams.     

4种城市绿化树种叶片PAHs含量特征与叶面结构的关系

用气质联用仪测定了长沙市樟树(Cinnamomu camphora)、广玉兰(Magnolia grandiflora)、桂花(Opsmanthus fragrans)和红檵木(Redrlowered loropetalum)4个主要绿化树种叶片中PAHs含量,同时测定了叶片的气孔密度、气孔长宽比、叶片的宽长比和叶面积等叶面结构特征值,探讨了叶面结构与叶片中PAHs含量的关系。结果表明:红檵木叶片的PAHs含量最高,为11.13mg·kg-1,16种PAHs在4树种叶片中均有不同程度的检出,其中以3环和4环为主,菲的浓度最高。除桂花外,在气温较低的秋冬季节,其余3种植物叶片气孔密度大PAHs含量高。叶面宽长比、气孔长宽比均与叶片PAHs含量呈极显著正相关,而叶面积与PAHs含量呈极显著负相关。表明叶面结构是影响叶片PAHs含量的重要因素。研究结果可为城市绿化树种合理选择与配置提供科学依据。     

Neuromodulatory unpaired median neurons in the New Zealand tree weta, Hemideina femorata

Wetas are ancient Gondwanan orthopterans (Anostostomatidae) with many species endemic to New Zealand. Like all Orthoptera they possess efferent neuromodulatory dorsal unpaired median (DUM) neurons, with bilaterally symmetrical axons, that are important components of motor networks. These neurons produce overshooting action potentials and are easily stimulated by a variety of external mechanosensory stimuli delivered to the body and appendages. In particular, stimulation of the antennae, mouth parts, tarsi and femora of the legs, abdomen, cerci and ovipositor is very effective in activating DUM neurons in the metathoracic ganglion of wetas. In addition, looming visual stimuli or light on-, light off-stimuli excite many metathoracic DUM neurons. These DUM sensory reflex pathways remain viable after the prothoracic to subesophageal connective is cut, whereas in locusts such reflex pathways are interrupted by the ablation. This suggests that, in wetas, sensory reflex pathways for DUM activation are organized in a less centralized fashion than in locusts, and may therefore reflect a plesiomorphic evolutionary state in the weta. In addition, many weta DUM neurons exhibit slow rhythmic bursting which also persists following the connective ablation.     

Geographic parthenogenesis and the common tea‐tree stick insect of New Zealand

Worldwide, parthenogenetic reproduction has evolved many times in the stick insects (Phasmatidae). Many parthenogenetic stick insects show the distribution pattern known as geographic parthenogenesis, in that they occupy habitats that are at higher altitude or latitude compared with their sexual relatives. Although it is often assumed that, in the short term, parthenogenetic populations will have a reproductive advantage over sexual populations; this is not necessarily the case. We present data on the distribution and evolutionary relationships of sexual and asexual populations of the New Zealand stick insect, Clitarchus hookeri. Males are common in the northern half of the species’ range but rare or absent elsewhere, and we found that most C. hookeri from putative‐parthenogenetic populations share a common ancestor. Female stick insects from bisexual populations of Clitarchus hookeri are capable of parthenogenetic reproduction, but those insects from putative‐parthenogenetic populations produced few offspring via sexual reproduction when males were available. We found similar fertility (hatching success) in mated and virgin females. Mated females produce equal numbers of male and female offspring, with most hatching about 9–16 weeks after laying. In contrast, most eggs from unmated females took longer to hatch (21–23 weeks), and most offspring were female. It appears that all C. hookeri females are capable of parthenogenetic reproduction, and thus could benefit from the numerical advantage this yields. Nevertheless, our phylogeographic evidence shows that the majority of all‐female populations over a wide geographic area originate from a single loss of sexual reproduction.     

A study of the glucofructofuranan from the New Zealand cabbage tree Cordyline australis

Extraction of the roots of the New Zealand cabbage tree Cordyline australis with water gave a glucofructofuranan in 60% yield (dry-weight basis). Viscosity measurements on aqueous solutions of the polysaccharide, and vapor pressure osmometry of the polysaccharide peracetate, showed the number average molecular weight of the glucofructofuranan to be 3000. Complete hydrolysis with dilute acid gave only -fructose and -glucose, in the ratio of 16:1. The polysaccharide was methylated by using dimethyl sulfoxide—sodium hydroxide—methyl iodide, and the methylated polymer was hydrolyzed to give 1,3,4,6-tetra-O-methylfructose (5.6 mol), 2,3,4,6-tetra-O-methylglucose (1 mol), 1,3,4-tri-O-methylfructose (8.4 mol), 2,3,4-tri-O-methylglucose (0.1 mol), and 3,4-di-O-methylfructose (2.7 mol). These results, supported by ¹³C-n.m.r. analyses, showed that the polymer is a highly branched glucofructofuranan containing mainly (1→2)-linked β- -fructofuranosyl residues, with branching at O-6 of 15% of the -fructosyl residues.     

Multiple factors determine the rate of increase of an invading non-native tree in New Zealand

We reconstructed the invasion of a non-native tree (hawthorn, Crataegus monogyna) into fire-induced grassland in montane South Island, New Zealand. Using the relationship between height and age to reconstruct the rate of increase of the population, we identified three distinct invasion phases. We hypothesised that these related to the abundance of woody vegetation and therefore of non-native blackbirds (Turdus merula), the primary disperser of hawthorn in this environment. From the 1930s to 1959, increase was relatively slow, with hawthorn spread probably constrained due to browsing of seedlings by European rabbits (Oryctolagus cuniculus) and the low abundance of a native N-fixing shrub (matagouri, Discaria toumatou) providing few perches and nesting sites for blackbirds and safe sites for hawthorn establishment. Subsequently, from 1959 to 1976, hawthorn showed greater than six fold acceleration in its rate of population increase, resulting largely from intensive rabbit control, less frequent fires, and aerial topdressing of phosphate fertilizer promoting the growth of matagouri scrub. In addition, maturing hawthorn trees provided additional food and nesting sites for blackbirds. Hawthorn population increase slowed again from 1976, possibly because most suitable habitat in the immediate vicinity of the population neared saturation. From this case study we have constructed a general hypothesis for the factors determining the rate of invasion of matagouri—grassland habitats by bird-dispersed non-native woody plants in montane New Zealand.     

Essential oils from the leaves of three New Zealand species of Pseudopanax (Araliaceae)

Essential oils from three of the eleven endemic New Zealand species of Pseudopanax, P. arboreus, P. discolor and P. lessonii, were found to have a fairly uniform composition which was different from that of the oils of Raukaua species that were formerly classified in the Pseudopanax genus. Oils of the three Pseudopanax species all contained significant proportions of viridiflorol and a closely related unidentified hydroazulene alcohol in common. In addition, the oil of P. arboreus contained bicyclogermacrene, linalool and long chain hydrocarbons. The oil of P. discolor contained nerolidol in abundance (36.3%) together with linalool and epi-alpha-muurolol. The oil of P. lessonii contained a complex mixture of sesquiterpene alcohols including epi-alpha-muurolol and a mixture of long chain hydrocarbons. Nerolidol and linalool provided the oil of P. discolor with a pleasant floral aroma, but the yield of oil was very low (0.01%).     

海桐花属一些种类的新异名

作为对英文版“Flora of China”海桐花科的分类学修订结果,提出了海桐花属6个种的8个新异名,并分别进行了讨论。     

The geometry of unfolding tree leaves

Leaves of hornbeam (Carpinus betulus) and beech (Fagus sylvaticus) were modelled to a first approximation as plane surfaces, with straight parallel folds, using numerical methods. In both species the lateral veins, when the leaves are outstretched, are angled at 30 to 50 degrees from the centre vein. A higher angle allows the leaf to be folded more compactly within the bud, but it takes longer to expand. This may allow the plant to optimize the timing of leaf deployment with ecological and physiological conditions.     

New synonymies of some species of Pittosporum (Pittosporaceae)

As part of a revision of Chinese Pittosporum Banks ex Gaertn. for the forthcoming account of Pittosporaceae in “Flora of China”, Volume 9, eight names, all described from China, are reduced to synonymy as follows: P. illicioides Makino var. angustifolium T. C. Huang ex S. Y. Lu, syn. nov. and P. illicioides var. stenophyllum P. L. Chiu ex H. T. Chang & S. Z. Yan, syn. nov., both under P. illicioides; P. densinervatum H. T. Chang & S. Z. Yan, syn. nov. and P. longicarpum S. K. Wu ex C. Y. Wu, syn. nov., both under P. kweichowense Gowda var. kweichowense; P. polycarpum H. T. Chang & S. Z. Yan, syn. nov. under P. paniculiferum H. T. Chang & S. Z. Yan; P. membranifolium S. C. Huang ex C. Y. Wu, syn. nov. under P. perryanum Gowda var. perryanum; P. motanthum C. Y. Wu, syn. nov. under P. podocarpum Gagnep. var. podocarpum; and P. tobira (Thunb.) W. T Aiton var. chinense S. Kobayashi, syn. nov. under P. tobira.     

Direct seeding of indigenous tree and shrub species into New Zealand hill country pasture

Summary Our study aimed to examine the applicability of a native plant restoration technique involving close grazing, blanket herbicide spraying and mob stocking (to trample the seed into the soil) for establishing New Zealand native tree and shrub species into exotic hill country pasture. This approach represents an alternative to the usual spaced-planting of seedlings in the context of an indigenous vegetation restoration programme. Field-collected seed of Cabbage Tree ( Cordyline australis ), Kahikatea ( Dacrycarpus dacrydioides ), Kanuka ( Kunzea ericoides ), Karamu ( Coprosma robusta ), Kohuhu ( Pittosporum tenuifolium ), Koromiko ( Hebe stricta ), and Manuka ( Leptospermum scoparium ) were germination tested in the laboratory, and broadcast sown in two field experiments in spring 2001 and autumn 2002. The spring-sown experiment tested the effect of mob stocking and the autumn-sown experiment tested the effect of mob stocking and sowing rate. Laboratory germination varied widely among species (0–88%). In the field, the two shrubs, Koromiko and Karamu, established densities of up to 5 and 1.2 plants/m², respectively, after 2.5 years. Autumn emergence for these two species strongly related to sowing rate. Three tree species, Cabbage Tree, Kahikatea and Manuka, emerged in the field but did not survive beyond 6 months. Mob stocking was effective in spring but not autumn sowing, implicating soil moisture content as an important factor in germination success. The study demonstrated that the direct seeding technique was successful for two shrub species, highlighting the potential for development of a cost-effective native plant restoration approach.     

Nitrate reduction in citrus tree leaves

Summary A nitrate-reducing enzyme system is active in citrus tree leaf fragments. The system is inactivated in disrupted and damaged cells of leaf macerate. The measurement of nitrite as an indication of nitrate reductase activity is some times misleading because of its rapid disappearance due to high nitrite reductase activity.Contribution from the National and University Institute of Agriculture, Rehovot, Israel. 1964 Series, No. 710-E.