祁连山保护区东端气象因子与阔叶林火险等级相关性分析

通过对祁连山保护区东端阔叶林可燃物含水率与气象因子关系分析,采用统计回归法,建立了阔叶林可燃物含水率与气象要素关系模型,以阔叶林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区东端阔叶林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区东端阔叶林火灾预测预防提供了科学依据。     

祁连山保护区东端气象因子与灌木林火险等级相关性分析

通过对祁连山保护区东端灌木林可燃物含水率与气象因子关系分析,采用统计回归法,建立了灌木林可燃物含水率与气象要素关系模型,以灌木林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区东端灌木林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区东端灌木林火灾预测预防提供了科学依据。     

祁连山保护区东端气象因子与针阔混交林死体可燃物含水率拟合模型构建

分析了祁连山保护区东端气象因子与针阔混交林死体可燃物含水率的关系,结果表明,祁连山保护区东端针阔混交林死体可燃物含水率与降水量、温度、相对湿度、连续干旱天数、风速和蒸发量6个气象因子显著相关,显著性水平为0.05。以针阔混交林死体可燃物含水率为应变量,降水量、温度、相对湿度、连续干旱天数、风速和蒸发量为自变量,建立了拟合模型。经检测,模型估算值与实测结果误差较小,可为祁连山保护区东端针阔混交林火灾预测预防提供较为准确的数据。     

祁连山保护区东端气象因子与祁连圆柏林火险等级相关性分析

通过对祁连山保护区东端祁连圆柏(Sabina Przewalskii)林可燃物含水率与气象因子关系分析,采用统计回归法,建立了祁连圆柏林可燃物含水率与气象要素关系模型,以祁连圆柏林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区东端祁连圆柏林森林火险等级对应的气象因子。结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区东端祁连圆柏林火灾预测预防提供了科学依据。     

祁连山保护区东端气象因子与青海云杉林火险等级相关性分析

通过对祁连山保护区东端青海云杉(Picea crassifolia)林可燃物含水率与气象因子相关性分析,采用统计回归法,建立了青海云杉林可燃物含水率与气象要素关系模型,以青海云杉林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区东端青海云杉林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区东端青海云杉林火灾预测预防提供了科学依据。     

祁连山保护区东端气象因子与草原火险等级相关性分析

通过对祁连山保护区东端草原可燃物含水率与气象因子相关性分析,采用统计回归法,建立了草原可燃物含水率与气象要素关系模型,以草原死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区东端草原火险等级对应的气象因子,结果表明:草原可燃物含水率模型模拟效果较好,引入草原可燃物含水率气象预测模型可提高草原火险气象指数模型的应用效果,为祁连山保护区东端草原火灾预测预防提供了科学依据。     

祁连山保护区西端气象因子与阔叶林火险等级相关性分析

通过对祁连山保护区西端阔叶林可燃物含水率与气象因子关系分析,采用统计回归法,建立了阔叶林可燃物含水率与气象要素关系模型,以阔叶林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区西端阔叶林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区西端阔叶林火灾预测预防提供了科学依据。     

祁连山保护区西端气象因子与灌木林火险等级相关性分析

通过对祁连山保护区西端灌木林可燃物含水率与气象因子关系分析,采用统计回归法,建立了灌木林可燃物含水率与气象要素关系模型,以灌木林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区西端灌木林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区西端灌木林火灾预测预防提供了科学依据。     

祁连山保护区西端气象因子与祁连圆柏林火险等级相关性分析

通过对祁连山保护区西端祁连圆柏(Sabina Przewalskii)林可燃物含水率与气象因子关系分析,采用统计回归法,建立了祁连圆柏林可燃物含水率与气象要素关系模型,以祁连圆柏林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区西端祁连圆柏林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区西端祁连圆柏林火灾预测预防提供了科学依据。     

祁连山保护区西端气象因子与青海云杉林火险等级相关性分析

通过对祁连山保护区西端青海云杉(Picea crassifolia)林可燃物含水率与气象因子相关性分析,采用统计回归法,建立了青海云杉林可燃物含水率与气象要素关系模型,以青海云杉林死体可燃物引燃含水率为基准,结合燃烧实验,确定了祁连山保护区西端青海云杉林森林火险等级对应的气象因子,结果表明:森林可燃物含水率模型模拟效果较好,引入森林可燃物含水率气象预测模型可提高森林火险气象指数模型的应用效果,为祁连山保护区西端青海云杉林火灾预测预防提供了科学依据。     

Effects of surface and light conditions of fallen logs on the emergence and survival of coniferous seedlings and saplings

We surveyed the germination number (N _cs) of 2-year and a 1-year survival of Abies sachalinensis and Picea jezoensis seedlings and saplings on 29 fallen logs from 2004 to 2005 in a natural coniferous forest in Hokkaido, northern Japan, in relation to the surface and light conditions of fallen logs. Moss height (H _moss), log hardness (Hardness), and the area of fallen log (Area) were measured as the surface conditions by each 1-m block from bottom to top of all fallen logs. The relative photosynthetic photon flux density (rPPFD) 10 cm above the tallest seedling in each block was measured as the light condition. In addition, the height of the tallest seedling or sapling in each block (H _max), the difference between a height of each seedling and sapling and the H _max (Shading), and a height of seedlings and saplings in 2004 (H _ini) were considered. N _cs of A. sachalinensis was affected by Hardness and Area, whereas N _cs of P. jezoensis was affected by H _moss, Hardness, Area, H _max, and rPPFD. The survival of seedlings (height < 5 cm) and saplings (5 cm ≤ height < 50 cm) were affected by H _ini, rPPFD, and shading for both species. However, the survival of P. jezoensis saplings was more sensitive to decrease in rPPFD and increase of shading than that of A. sachalinensis. Therefore, seedling emergence was influenced by surface conditions, whereas survival was affected by light conditions. Furthermore, P. jezoensis emergence and survival were more sensitive to surface and light conditions than that of A. sachalinensis.     

Effect of auxins (IBA and NAA) and season on rooting of juvenile and mature hardwood cuttings of Robinia pseudoacacia and Grewia optiva

Juvenile (2 year old trees) and mature hardwood (15 year old trees) cuttings of Robinia pseudoacacia and Grewia optiva were tested for their capacity to form roots. Cuttings were prepared in spring, monsoon and winter seasons and treated with different concentrations (250, 500 and 750 mg/l) of IBA and NAA. These were planted in a mist chamber maintained at 25±1°C with relative humidity >70%. Juvenile cuttings of both species rooted significantly better than mature hardwood cuttings in all three seasons, and the age effect was more pronounced in auxin treated cuttings. The highest rooting in juvenile (83.3%) and mature (66.6%) cuttings was observed with the NAA (500 mg/l) treatment in R. pseudoacacia during the spring season. In G. optiva, IBA (250 mg/l) in the monsoon season was most effective and yielding a maximum of 80% and 70% rooting in juvenile and mature cuttings, respectively. Auxin treatments also significantly enhanced the number of roots, root length, leaf number and leaf area. Statistical analysis of data revealed that interactions between age, season and treatments were significant at P <0.05 level for R. pseudoacacia and non-significant for G. optiva.     

Aluminum tolerance and aluminum-induced deposition of callose and lignin in the root tips of Melaleuca and Eucalyptus species

We exposed the roots of nine Myrtaceae species (Melaleuca bracteata F. Muell., Melaleuca cajuputi Powell, Melaleuca glomerata F. Muell., Melaleuca leucadendra [L.] L., Melaleuca quinquenervia [Cav.] S.T. Blake, Melaleuca viridiflora Sol. ex Gaertner, Eucalyptus camaldulensis Dehnh., Eucalyptus deglupta Bl., and Eucalyptus grandis W. Hill ex Maiden) to 1 mM Al in a nutrient solution for either 24 h or 20 days to evaluate their sensitivity to excess Al and to determine whether callose and lignin formation can be used as interspecific indicators of Al sensitivity. Inhibition of root elongation by Al varied among the species. Melaleuca leucadendra, M. cajuputi, E. grandis, M. quinquenervia, and E. deglupta were tolerant to 1 mM Al, whereas M. viridiflora, E. camaldulensis, M. glomerata, and M. bracteata were sensitive to 1 mM Al. We found that Al induced callose formation in the root tips of each species, but lignin was formed only in the root tips of the most sensitive species, M. bracteata. Root elongation at 1 mM Al was negatively correlated with Al-induced callose formation but not with the Al-induced lignin formation in the root tips. These results suggest that Al-induced callose formation, rather than lignin formation, can be used as an interspecific indicator of Al sensitivity.     

Allelopathic effects of eucalyptus and the establishment of mixed stands of eucalyptus and native species

Allelopathic effects of eucalyptus are widely reported and are considered the major factor limiting the establishment of native species in eucalyptus forests. However, reports of the allelopathic effects of eucalyptus are mostly based on laboratory bioassay, not on field trials. In the present study, we conducted field trials to determine the allelopathic effects of eucalyptus and to develop strategies for establishment of mixed stands of native species and eucalyptus. In the field, seed germination and seedling survivorship of native species were determined in the presence and absence of eucalyptus leaf litter or living roots. In the seed germination experiment, seed germination rate of Delonix regia was higher than for Elaeocarpus sylvestris and Tsoongiodendron odorum. Seed germination rates of E. sylvestris and T. odorum were low in both the presence and absence of eucalyptus treatments. The germination rate of D. regia was significantly inhibited by all eucalyptus treatments, but only during the early period. In the seedling establishment experiment, seedling survivorship of E. sylvestris and Michelia macclurel was not inhibited by any treatments, but the seedling survivorship of Schima superba was significantly inhibited by eucalyptus litter addition alone. Seedling height of S. superba and M. macclurel was significantly suppressed when eucalyptus roots were present in treatments, but the seedling height of E. sylvestris was only significantly suppressed by the treatment of roots alone. We propose two strategies for establishment of mixed stands of native species and eucalyptus: (1) direct seed-sowing is effective only for those species (e.g. D. regia) with high germination rates in natural conditions; (2) seedling transplants are more efficient approach for establishing species (e.g. E. sylvestris) with low germination rates. We suggest that mixed plantations of eucalyptus and E. sylvestris can be established by transplanting seedlings of E. sylvestris into eucalyptus plantations.     

Effects of solid water and foliar fertilizer on survival and growth of seedlings in sand prevention and control

To promote afforestation in sandy lands and increase the effects of prevention and control of desertification, the application of a new drought-resistant product—solid water and foliar fertilizer “Shifengle”—was studied. A comparison of three treatments (solid water, foliar fertilizer, and control) showed that both solid water and foliar fertilizer increased plant survival rate by 10% and 18.2%, respectively. Afforestation survival rates of Salix psammophila and Hedysarum mongolicum reached over 90%. In addition, height and crown growth as well as biomass of seedlings were improved by the treatments. __________ Translated from Journal of Beijing Forestry University, 2006, 28(3): 76–80 [译自: 北京林业大学学报]     

An assessment of the benefits and limitations of the shamba agroforestry system in Kenya and of management and policy requirements for its successful and sustainable reintroduction

The shamba system involves farmers tending tree saplings on state-owned forest land in return for being permitted to intercrop perennial food crops until canopy closure. At one time the system was used throughout all state-owned forest lands in Kenya, accounting for a large proportion of some 160,000 ha. The system should theoretically be mutually beneficial to both local people and the government. However the system has had a chequered past in Kenya due to widespread malpractice and associated environmental degradation. It was last banned in 2003 but in early 2008 field trials were initiated for its reintroduction. This study aimed to: assess the benefits and limitations of the shamba system in Kenya; assess the main influences on the extent to which the limitations and benefits are realised and; consider the management and policy requirements for the system’s successful and sustainable operation. Information was obtained from 133 questionnaires using mainly open ended questions and six participatory workshops carried out in forest-adjacent communities on the western slopes of Mount Kenya in Nyeri district. In addition interviews were conducted with key informants from communities and organisations. There was strong desire amongst local people for the system’s reintroduction given that it had provided significant food, income and employment. Local perceptions of the failings of the system included firstly mismanagement by government or forest authorities and secondly abuse of the system by shamba farmers and outsiders. Improvements local people considered necessary for the shamba system to work included more accountability and transparency in administration and better rules with respect to plot allocation and stewardship. Ninety-seven percent of respondents said they would like to be more involved in management of the forest and 80% that they were willing to pay for the use of a plot. The study concludes that the structural framework laid down by the 2005 Forests Act, which includes provision for the reimplementation of the shamba system under the new plantation establishment and livelihood improvement scheme (PELIS) [It should be noted that whilst the shamba system was re-branded in 2008 under the acronym PELIS, for the sake of simplicity the authors continue to refer to the ‘shamba system’ and ‘shamba farmers’ throughout this paper.], is weakened because insufficient power is likely to be devolved to local people, casting them merely as ‘forest users’ and the shamba system as a ‘forest user right’. In so doing the system’s potential to both facilitate and embody the participation of local people in forest management is limited and the long-term sustainability of the new system is questionable. Suggested instruments to address this include some degree of sharing of profits from forest timber, performance related guarantees for farmers to gain a new plot and use of joint committees consisting of local people and the forest authorities for long term management of forests.

Species and control of insect pests and major diseases of Torreya grandis merrillii

From January 2001 to December 2004, the investigation on the species of insect pests and diseases in Torreya grandis Merrillii was conducted and integrated control technologies of the main insect pests and diseases were studied in Zhuji, Shaoxin, Shenzhou, Dongyang, and Jiande counties of Zhejiang Province. Via field survey, a system of regular observations, 55 species of insect pests belonging to 9 orders and 29 families, and 4 species of diseases were recorded. Among them, Lepteucosma torreyae and Macrolygus torreyae were found to be new species. The biological characteristics of the major insect pests and diseases, such as Rhyncaphytoptus abiesis, Helicobasidium compacum, Erwinia carotovora, Chlorella sp., Macrolygus torreyae, and Lepteucosma torreyae, were primarily recorded, and their outbreaks and epidemics were researched. The forecasting method for Lepteucosma torreyae was established. Based on strengthening cultivation and management, integrated control measures were put forward including physical, biologic and chemical methods. Medications with higher effect and lower toxicity were screened by comparing the effect of different pesticide treatments. __________ Translated from Journal of Zhejiang Forestry College, 2005, 22(5): 545–552 [译自: 浙江林学院学报, 2005, 22(5): 545–552]     

Soil fertility changes and response of maize and beans to green manures of leucaena,sesbania and pigeonpea

Three multipurpose tree species (MPTS)-leucaena (Leucaena leucocephala), sesbania (Sesbania sesban var. nubica) and pigeonpea (Cajanus cajan) were pruned at a height of 60 cm above the ground every two months, and resulting plant biomass was incorporated into the soil as green manure. For comparison, maize (Zea mays) stover was also incorporated into some plots, while some other plots were left fallow. Varying quantities of plant biomass which were incorporated into the soil over a period of 12 months caused large changes in major soil plant nutrients, and it substantially improved soil fertility. To test for improved soil fertility, test crops of maize and beans (Phaseolus vulgaris) were grown on the plots after six biomass incorporations of 4806, 13603, 16659 and 7793 kg. ha^–1yr^–1 for pigeonpea, sesbania leucaena and maize, respectively. Responses of the test crops indicated that sesbania and leucaena green manures improved maize stover, cobs and grain yields; and bean haulms and grain yields by 77.6% when compared to fallow plots. Residual effects of green manures still resulted in significant (P < 0.05) yield differences in the test cropin the third testing season. Economic significance of green manures in increasing food crop yields to small scale farmers is discussed.     

Antituberculosis activity of natural and semisynthetic azorellane and mulinane diterpenoids

The antituberculosis activity of 14 natural azorellane and mulinane diterpenoids isolated from Azorella compacta, Azorella madreporica, Mulinum crassifolium, and Laretia acaulis, together with eight semisynthetic derivatives, was evaluated against two Mycobacterium tuberculosis strains. The natural azorellanes azorellanol (3) and 17-acetoxy-13-α-hydroxyazorellane (6), and the semisynthetic mulinanes 13-hydroxy-mulin-11-en-20-oic-acid methyl ester (13) and mulinenic acid methyl ester (23), showed the strongest activity, with MIC values of 12.5 μg/mL against both strains. The methylated derivatives 13-hydroxy-mulin-11-en-20-oic-acid methyl ester (13), mulin-11,13-dien-20-oic acid methyl ester (15) and mulinenic acid methyl ester (23) proved to be more active than the parent compounds.     

Impact of weather variables and season on sporulation of Phytophthora pluvialis and Phytophthora kernoviae

Phytophthora pluvialis and Phytophthora kernoviae are the causal agents of important needle diseases on Pinus radiata in New Zealand. Little is known about the epidemiology of the diseases, making the development of control strategies challenging. To investigate the seasonality and climatic drivers of sporulation, inoculum traps, consisting of pine fascicles floating on water in plastic containers, were exchanged fortnightly at five sites in P. radiata plantations between February 2012 and December 2014. Sections of needle baits were plated onto selective media and growth of Phytophthora pluvialis and P. kernoviae recorded. To explore the generalizability of these data, they were compared to detection data for both pathogens from the New Zealand Forest Health Database (NZFHDB). Further, equivalent analyses on infection of Rhododendron ponticum by P. kernoviae in Cornwall, UK allowed the comparison of the epidemiology of P. kernoviae across different host systems and environments. In New Zealand, inoculum of P. pluvialis and P. kernoviae was detected between January–December and March–November, respectively. Inoculum of both species peaked in abundance in late winter. The probability of detecting P. pluvialis and P. kernoviae was greater at lower temperatures, while the probability of detecting P. pluvialis also increased during periods of wet weather. Similar patterns were observed in NZFHDB data. However, the seasonal pattern of infection by P. kernoviae in the UK was the opposite of that seen for sporulation in New Zealand. Phytophthora kernoviae was likely limited by warmer and drier summers in New Zealand, but by colder winter weather in the UK. These results emphasize the importance of considering both environmental drivers and thresholds in improving our understanding of pathogen epidemiology.