Predicting the severity of Swiss needle cast on Douglas-fir under current and future climate in New Zealand

Phaeocryptopus gaeumannii, the causal agent of Swiss needle cast, is widely distributed in plantations of Douglas-fir (Pseudotsuga menziesii) throughout New Zealand, causing premature abscission of needles and significant growth losses. Data were collected from 34 sites, selected to span a broad range of environmental conditions within New Zealand, to (i) develop models of infection and foliage retention, F_ret, and (ii) from these models predict F_ret by region under current and future climates, using the factorial combination of 12 Global Climate Models (GCMs) and three emission scenarios (low, B1; medium, A1B; and high, A2).     

观光木人工林生物量及生产力研究

对广西南宁良凤江国家森林公园27年生的观光木生物量和生产力进行测定研究,分析观光木人工林不同径阶生物量的分配规律和林分生物量、生产力,并根据林木各器官之间的相关关系,建立D2H与各器官生物量的估测模型。结果表明,观光木生物量随着径阶的增大而增大,不同径阶间差异显著;通过不同径阶D2H拟合的生物量估算模型,拟合精度高,可用于实际生产对该林分生物量的估算;观光木林分生物量为102.57 t/hm2,其中乔木层占了87.07%,林下灌木层、草本层及腐殖质层生物量分别为8.61 t/hm2、1.83 t/hm2、2.82 t/hm2。观光木人工林林分生产力为7.4 t/(hm2.a),具有较高的净生产力。     

Litter removal impacts on soil biodiversity and eucalypt plantation development in the seasonal tropics

The little layer of tree plantations provides primary nutrients for uptake,buffers changes in soil moisture,and provides habitat and substrate to soil epigeic fauna.However,this layer in eucalypt plantations is often removed to reduce fuel load during the fire season in the Brazilian savanna(Cerrado).Therefore,it is necessary to quantify the effects of changes in litter dynamics on the function of these plantations,on key nutrient cycling processes and on epigeic fauna diversity and abundance.In...     

广西桉树人工林种植情况及其对生态环境的影响

为了探讨广西桉树对环境的影响,该文介绍广西桉树种植情况,总结栽种桉树的优势,探讨发展桉树存在的问题.作者认为桉树无论是吸收还是带走的矿质营养量,较其他作物相比都是相对较少的.关于桉树引起土壤肥力衰退的情况是存在的,也是正常现象,桉树人工林生长快、密度大,人们收获的木料也多得多,其吸收的矿质营养自然要多.桉树引发西南地区...     

Susceptibility of Eucalyptus globulus ssp. globulus to sawfly (Perga affinis ssp. insularis) attack and its potential impact on plantation productivity

Sawflies (Perga species) are leaf-damaging pests of the major plantation tree species Eucalyptus globulus ssp. globulus. This work describes the patterns of quantitative genetic variation in susceptibility to attack by Perga affinis ssp. insularis, based on data from a large open-pollinated trial containing genetic material from throughout the geographic range of E. globulus ssp. globulus. Forty three per cent of the trees in the trial exhibited damage from sawflies in either their sixth or seventh growth seasons. The incidence of damage was genetically based, with significant variation between geographic races of E. globulus ssp. globulus and highly heritable (h²=0.43±0.05) variation in damage incidence within races. Susceptibility to sawfly damage significantly affects plant fitness with both genetic and environmental correlations demonstrating that sawfly damage causes slow growth and increased mortality of trees. Mild and severe sawfly damage resulted in 16 and 31% reduction in the basal area of surviving trees, and the effect was consistent across races and families. Based on this data, we propose a model predicting relative plantation productivity of races of different susceptibility under different infestation regimes.     

Vulnerability of Pinus cembra L. in the Alps and the Carpathian mountains under present and future climates

Proactive management should be applied within a forest conservation context to prevent extinction or degradation of those forest ecosystems that we suspect will be affected by global warming in the next century. The aim of this study is to estimate the vulnerability under climate change of a localized and endemic tree species Pinus cembra that occurs in the alpine timberline. We used the Random Forest ensemble classifier and available bioclimatic and ecological data to model present and future suitable areas for P. cembra and estimate its current and future vulnerability. Future projections for years 2020, 2050 and 2080 were simulated using two IPCC Special Report on Emission Scenarios run under four global climate models.     

连栽对巨尾桉人工林生物量和生产力的影响

对不同连栽代数的巨尾桉人工林的生物量和生产力进行研究。按径级标准木法,测定3年生不同连栽代数的巨尾桉人工林生物量,建立其估算模型,计算出3年生不同连栽代数巨尾桉人工林分的生物量和生产力。结果表明：第1,2,3代巨尾桉人工林年生物量分别为37.81,37.02,26.59 t/ hm2;林分年净生产力分别为12.60,12.34,8.86 t/（hm2·a）;干材年生产力分别为6.12,6.14,4.33 t/（hm2·a）。随着连栽代数的增加,林分的生物量和生产力下降趋势不明显,第2代林干材生产力高于第1,3代林。     

Past,present and future of industrial plantation forestry and implication on future timber harvesting technology

Plantation forests are established,and expanding,to satisfy increasing global demand for timber products.Shifting societal values,such as safety,productivity,environmental,quality and social are influencing the plantation forestry sector.This is primarily driven through an ever increasing world population,which in turn influences the way nations view the value systems by which they live.More people require more resources—also forest products.Also,the availability of information is influencing the pace of technological development.These changes could result in a difference in the management of plantations that could affect the forest engineering systems of the future.This review aimed to summarize the current status of plantation forests;summarize future developments and possible scenarios in forest plantation management for the various products;and assess whether these developments in a plantation environment could affect the harvesting systems used.Factors influencing the form of plantations include the type and nature of the plantation owner;the change in demand for different and new forest products;climate change factors,including the use of biomass for energy,carbon sequestration and trading;ecosystem services and other products and services;and sustainability certification of forest management.The impact and influence of these factors were summarised into a series of key drivers that will influence the technology used in harvesting machines,as well as the choice of harvesting machines,systems and methods.These drivers were the effect of variations in tree size,the expansion of plantation areas onto more difficult terrain,diversity in plantation design,increased attention towards site impacts and the increased use of biomass for energy.Specific information is provided regarding how the harvesting systems could be affected.     

Predicting the severity of Dothistroma on Pinus radiata under current climate in New Zealand

Despite being a damaging foliar disease of Pinus species little research has characterised spatial variation in disease severity of Dothistroma needle blight at a macroscale. Using an extensive dataset describing Dothistroma needle blight severity (S_sev) on plantation grown Pinus radiata stands distributed widely across New Zealand the objectives of this research were to (i) develop a regression model describing S_sev, (ii) use this model to identify key drivers of S_sev, their functional form and relative importance, and (iii) develop spatial predictions of S_sev for New Zealand P. radiata under current climate. Using an independent validation dataset, the final model accounted for 72% of the variance in S_sev using four significant (P < 0.001) explanatory variables and an isotrophic exponential model to account for the spatial covariance in the data. S_sev was most sensitive to mean air temperature from November to April (T_Nov-Apr), followed by mean relative humidity from October to April (RH_Oct-Apr), mean total November rainfall (P_Nov), and then stand age (A). There was a quadratic correlation between A and S_sev with S_sev increasing to a maxima at 12 years before declining. S_sev exponentially increased to a threshold with increases in both P_Nov and RH_Oct-Apr. The relationship between S_sev and T_Nov-Apr was quadratic with S_sev increasing to a maximum at T_Nov-Apr of 15.5 °C before declining at higher values of T_Nov-Apr. Spatial predictions of S_sev varied widely throughout New Zealand. Values of S_sev were highest in moderately warm wet environments in the North Island, and on the west coast of the South Island. In contrast, relatively low values of S_sev were predicted in drier eastern and southern regions of New Zealand.     

Assessing the effects of early silvicultural management on long-term site productivity of fast-growing eucalypt plantations: the Brazilian experience

Eucalyptus is the dominant and most productive planted forest in Brazil, covering around 3.4 million ha for the production of charcoal, pulp, sawtimber, timber plates, wood foils, plywood and for building purposes. At the early establishment of the forest plantations, during the second half of the 1960s, the eucalypt yield was 10 m³ ha^?1 y^?1. Now, as a result of investments in research and technology, the average productivity is 38 m³ ha^?1 y^?1. The productivity restrictions are related to the following environmental factors, in order of importance: water deficits > nutrient deficiency > soil depth and strength. The clonal forests have been fundamental in sites with larger water and nutrient restrictions, where they out-perform those established from traditional seed-based planting stock. When the environmental limitations are small the productivities of plantations based on clones or seeds appear to be similar. In the long term there are risks to sustainability, because of the low fertility and low reserves of primary minerals in the soils, which are, commonly, loamy and clayey oxisols and ultisols. Usually, a decline of soil quality is caused by management that does not conserve soil and site resources, damages soil physical and chemical characteristics, and insufficient or unbalanced fertiliser management. The problem is more serious when fast-growing genotypes are planted, which have a high nutrient demand and uptake capacity, and therefore high nutrient output through harvesting. The need to mobilise less soil by providing more cover and protection, reduce the nutrient and organic matter losses, preserve crucial physical properties as permeability (root growth, infiltration and aeration), improve weed control and reduce costs has led to a progressive increase in the use of minimum cultivation practices during the last 20 years, which has been accepted as a good alternative to keep or increase site quality in the long term. In this paper we provide a synthesis and critical appraisal of the research results and practical implications of early silvicultural management on long-term site productivity of fast-growing eucalypt plantations arising from the Brazilian context.     

燕山山地人工油松林单株生物量与生产力研究

对燕山山地9～48a生油松人工林20株标准木的研究表明:林木各器官生物量分配情况表现为干>枝>根>叶,建立了多个油松林木及器官生物量预测模型;提出油松人工林的RSR变化为0.135～0.293,平均值为0.193;分析了油松人工林中多年平均生产力与年生产力的变化情况,利用Logstic模型估测树龄48a时生产力为14205.3g/a,为本次调查的最高值,因此建议生产上主伐林龄应推迟到50a以后。     

Influence of plantation site and wastewater sludge fertilization on the performance and foliar nutrient status of two willow species grown under SRIC in southern Quebec (Canada)

Salix discolor Mühl. (Sd) and Salix viminalis L. (Sv) were planted under short-rotation intensive culture (SRIC) on three unirrigated abandoned farmland sites with different drainage conditions, one well-drained (S₁) and the other two poorly-drained (S₂, S₃). One dose of dried and granulated sludge equivalent to 150 (T₁) kg of “available” N ha⁻¹ was applied to some plots in the spring of the second season while others were left unfertilized (T₀). The aims of the experiment were (i) to investigate plant response (growth and productivity) to plantation site conditions and sludge application; (ii) study nutrient status by foliar analysis. Over three seasons, growth in height and aboveground biomass were greater for S. viminalis than for S. discolor on all sites. S. viminalis planted on poorly-drained site 2 had the highest biomass yield (45.28 t ha⁻¹). Both species showed best height and diameter growth on poorly-drained sites. For both species, best performances were obtained on wastewater sludge fertilized plots. Comparative foliar analysis suggested that unfertilized sandy soil (S₁) and low foliar nitrogen concentration and content were limiting factors in the performance of the two species. Soil nitrate concentration increased as a result of sludge application. Heavy metal accumulation from sludge does not represent a risk to the environment. It was concluded that S. viminalis had the best productivity on clay sites, and that a moderate dose of dried and pelleted sludge (150 kg of “available” N ha⁻¹) may be a good fertilizer during the establishment of willows in SRIC, and may reduce nitrate leaching.     

有害生物综合管理理论的发展及其展望

有害生物综合管理(IPM)自20世纪70年代被人们广泛接受以后得到了迅速的发展，文章对IPM的发展历史进行了简要的回顾，并对其近年来的进展进行了简述。     

桂东南地区火力楠人工林生物量研究

运用样方收获法等对桂东南地区31年生火力楠人工林的生物量、生产力进行研究.结果表明:不同部位生物量与测树因子D2H间存在密切相关关系,拟合的回归模型可靠度高;林分平均木单株生物量随径阶的增大而增大,且不同径阶间差异显著;林木不同部位平均生物量的排序依次为:树干>枝条>根兜>粗根>叶子>中根>细根>果实;乔木层总生物量为210.81 t/hm2,其中树干的生物量达132.86 t/hm2,占全株生物量的63.0%,年净生产力达6.8 t/(hm2·a).     

Predicting the productivity of a young hybrid poplar clone under intensive plantation management in northern Alberta,Canada using soil and site characteristics

Site productivity of the hybrid poplar clone Brooks6 was predicted using soil and site information from 6, 4-year-old plantations in north-east Alberta. Predictions were made at both the local and microsite scales. Percent sand (R ² = 0.352, P = 0.001) was the best single predictor of hybrid poplar productivity, showing a curved relationship. Soil pH also showed a curved but weaker relationship with hybrid poplar productivity (R ² = 0.133, P = 0.100). Maximum tree productivity occurred at sand contents between 55 and 70% and pH values near 6. Other variables, including foliar nutrient concentrations, foliar δ¹³C, electrical conductivity, depth of the A horizon and total chemistry of the soil, were also related to hybrid poplar productivity at the local and microsite scales. However, all of these variables were correlated to either soil texture (percent sand) or pH. At the microsite scale within plantations, percent sand was the most important predictor of tree productivity and explained more than 50% of the variability within plantations, although the relationship varied by plantation. In plantations with fine textures, sandier microsites were associated with increased growth while in sandy plantations, finer textured microsites were more productive. As a whole, the growth of the hybrid poplar clone Brooks6 appears to be mostly influenced by a combination of soil water and nutrient availability, the former being impacted by soil texture and the latter being governed by soil pH.     

Silvicultural systems for plantation mahogany in Africa: Influences of canopy shade on tree growth and pest damage

Overexploitation of the African mahoganies, Khaya anthotheca and K. ivorensis, could lead to their commercial extinction in the near future. Efforts to establish plantations to sustain supply have been discouraged by the shoot borer Hypsipyla robusta Moore. We hypothesized that there is a shade level at which Hypsipyla attack and branching are reduced, but height growth is adequate. We report on the growth of these African mahoganies and Hypsipyla attack under three different forest canopy shade levels: open (55% open sky), medium shade (26% open), and deep shade (11% open). Hypsipyla attack on K. anthotheca was 85%, 11%, and 0% attack in the open, medium, and deep shade treatments, respectively. However, growth in medium and deep shade was slow. Mean tree height for K. anthotheca was 413.8, 126.2, and 54.5 cm in the open, medium and deep shade treatments, respectively. K. ivorensis showed similar trends. The reduced growth under these shade levels limit the use of this strategy for controlling Hypsipyla attack.     

工业林木荷木材化学成分及其变异的研究

按照国家木材化学成分分析标准,对工业林木荷木材化学成分进行了测定,结果表明12年生和14年生木荷木材化学成分含量为：热水抽提物6．93％和5．06％;1％NaOH抽提物18．42％、17．42％;苯醇抽提物1．64％、2．48％;纤维素48．06％、50．72％;多戊糖20．99％、20．68％;木质素24．20％、23．10％;pH值为5．46和4．99。以上7个指标在树干不同高度的差异均未达到显著性水平。而热水、苯醇抽提物含量和pH值在两树龄间的差异达到1％显著水平,1％NaOH抽提物和主要化学成份含量的差异不显著。     

Spatio-temporal dynamic of suitable areas for species conservation in West Africa: eight economically important wild palms under present and future climates

Sustainable conservation of tropical resources required understanding of their distribution for effective assessment and definition of conservation priorities. In tropical areas, wild palms are highly valued keystone resources with growing demand for both subsistence uses and commercial trade. Here we focused on eight such species (Borassus aethiopum Mart., Eremospatha macrocarpa (G.Mann & H.Wendl.) H.Wendl., Hyphaene thebaica Mart., Laccosperma opacum (G.Mann & H.Wendl.) Drude, Phoenix reclinata Jacq., Raphia hookeri G.Mann & H.Wendl., Raphia sudanica A. Chev., and Raphia vinifera P.Beauv.). This study tested (i) how those palms distributions may be affected under future climate scenarios, and (ii) if species are effectively conserved currently and under future forecasts for their native distributional areas. Finally, we defined spatial priorities for the species’ conservation. Available bioclimatic and soil data layers were used for the modelling with maximum entropy approaches, and resulting maps were overlaid on the existing protected areas network. Results showed that much of the distribution of the species will remain largely stable, albeit with some expansion and retraction in some species; relationships with protected areas networks suggest that protected portions of species distributions will also remain stable. The areas identified as highest conservation priority differ between models even though the highest-priority areas holding most palm species are located along the coast (from Guinea to Nigeria). Further development of these analyses could aid in forming a more complete picture of the distributions and populations of the species, which in turn could aid in developing effective conservation strategies for this botanically important family.     

The influence of architectural and vegetational complexity in eucalypt plantations on communities of native wasp parasitoids: Towards silviculture for sustainable pest management

The pressure to attain sustainable primary production necessitates that novel alternatives to issues such as pest management are researched and developed. Given this context we tracked (using Malaise traps) the changes in diversity and abundance of native wasp parasitoids (belonging to the superfamily Ichneumonoidea, comprising the families Ichneumonidae and Braconidae) in three field trials comprising mixed plantings of Eucalyptus and/or Acacia. Our aim was to examine the influences of time since planting (determines architectural complexity), tree species composition and presence/absence of understorey vegetation (i.e. vegetational complexity) on populations of Ichneumonoidea. In the trial referred to as “GES1” the diversity of wasps increased from 10 to 37 morphospecies in the 3 years following planting; over this time some of the trees were estimated to have undergone an approximate 2.7-fold increase in height. In the plantings comprising Eucalyptus and/or Acacia in the proportions 10:90, 38:62 or 100:0, respectively (“GES2”), there was a tendency for Ichneumonoidea to be more abundant in arboreta in which the composition of Eucalyptus and Acacia was more closely matched (i.e. 38:62 eucalypts to acacias) compared to arboreta in which trees of one or other of the two genera dominated (i.e. 10:90 and 100:0 eucalypts to acacia). We also report a tendency for Ichneumonoidea to be less abundant in the halves of the third planting (“GES3”) where understorey vegetation had been killed with herbicide. Our results were in accordance with the general ecological principle that greater habitat complexity favours greater species diversity. We suggest that increasing the vegetational complexity of commercial Eucalyptus plantations in ways that favour desired species of Ichneumonoidea could be a means of enhancing the biological control of incipient populations of pest insects.