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Flotation techniques to improve viability of Juniperus polycarpos seed lots

Journal of Forestry Research 2017年第2期28卷 231-239页

作者： Abolfazl Daneshvar mulualem tigabu Asaddollah Karimidoost Per Christer Odén Southern Swedish Forest Research Centre Swedish University of Agricultural SciencesP.O.Box 49SE-230 53 AlnarpSweden Department of Natural Resources Gonbad Kavoos UniversityShahid Fallahi StreetP.O.Box 163GonbadIran Agriculture and Natural Resources Research Center of Golestan Province Beheshti Ave.P.O.Box ***GorganIran

The germination of freshly collected Juniperus polycarpos（K. Koch） seeds is very low and attributed to the large proportion of nonviable seeds in the seed ***, the aim of this study was to improve seed lot quality by removing nonviable seeds using two flotation techniques： incubation-drying-separation（IDS） and modified specific gravity（MSG） separation. We examined different IDS conditions（the specific incubation time, subsequent drying time and sorting media） for effectively sorting out nonviable seeds; and tested the feasibility of modified SG separation, which involved soaking seeds in water for a certain period before sorting in different concentrations of sucrose solution. Viable seeds were expected to absorb and metabolically bind more water during soaking than dead seeds could, and hence be sorted effectively depending on the viscosity of the sucrose solution. The viability of the seeds that floated or sank was determined in a topographical tetrazolium chloride（TTC） test. For the IDS trial,7 days incubation followed by 9 h of drying and sedimentation in pure water or 200 g L-1sucrose solution identified, respectively, 75 and 82 % of the seeds as viable（sunken） seeds. For the MSG trail, 77 % viable seeds were recovered in the sunken fraction when seeds were soaked for 48 h then immediately sorted in 600 g L-1sucrose solution. In both cases, the loss of viable seeds in the discarded floating fraction was only 4 %. The results demonstrate that both IDS and MSG separation techniques substantially improved seed lot viability, but MSG separation is simple and needs no modern seed handling facility, and its efficacy relies on seed mass（due to the initial soaking） and the specific density and viscosity of the flotation medium.

关键词： viable viability sorting sucrose tetrazolium incubation subsequent viscosity proportion immediately

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Effects of biochar and litter on carbon and nitrogen mineralization and soil microbial community structure in a China fir plantation

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Journal of Forestry Research 2019年第5期30卷 1913-1923页

作者： Ying Li Chuifan Zhou Yunxiao Qiu mulualem tigabu Xiangqing Ma College of Foresty Fujian Agriculture and Forestry UniversityFuzhou 350002People’s Republic of China Southern Swedish Forest Research Centre Swedish University of Agricultural SciencesBox 49230 53 AlnarpSweden Fujian Provincial Colleges University Engineering Research Center of Plantation Sustainable ManagementFuzhou 350002People’s Republic of China

To investigate the effects of biochar addition(1 or 3%)to the soil of a China fir plantation with or without litter,we conducted a 90-day incubation *** also studied the C and N dynamics and the microbial community structure of the *** soil without litter,the application of biochar at a rate of 3%significantly decreased CO2 emissions,while addition of 1%biochar had no *** application did not affect the net N mineralization rate but significantly reduced the NH4?concentration after 90 *** litter-enriched soil,biochar application had no significant effect on total CO2 emissions;however,application of 3%biochar significantly reduced the net N mineralization *** application to soil with or without litter immediately reduced the dissolved organic carbon(DOC)concentration independent of the application rate,which was primarily due to sorption of DOC by the *** fatty acid analysis demonstrated that both concentrations of added biochar to soil(with or without litter)altered the soil microbial community structure at the end of incubation,although the effect of biochar was not as strong as the effect of time or litter *** effect of biochar addition alone on microbial community structure was inconsistent over *** added to soil significantly increased fungi and reduced Gram-positive *** the presence of litter,biochar applied at both 1%and 3%significantly increased(p<0.05)the proportion of actinomycete only at day *** results indicate biochar as a potentially effective measure for C sequestration in the test soil of a China fir plantation,even in the presence of litter.

关键词： Biochar Litter China fir CO2 production Mineralization Microbial community structure

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Participatory forest management in Burkina Faso: Members' perception of performance

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Journal of Forestry Research 2014年第3期25卷 637-646页

作者： Pascaline Coulibaly-Lingani mulualem tigabu Patrice Savadogo Per-Christer Oden Centre National de la Recherche Scientifique et Technologique Institut de l’Environnement et de Recherches Agricoles Departement Produc-tions Forestieres 03 BP 7047 0uagadougou 03 Burkina Faso World Agroforestry Centre & International Crop Research Institute for the Semi-Arid Tropics ICRAF-ICRISAT West and Central Africa Swedish University of Agricultural Sciences Faculty of Forest Scienc-es Southern Swedish Forest Research Centre P.0.Box 49 SE-230 53 Alnarp Sweden

This study examines variations in the performance of partic-ipatory forest management programs among four forest management groups (FMGs) in southern Burkina Faso, and assesses the factors that influence their members’ perceptions of performance through a house-hold survey of 216 members. Variations in performance scores among the FMGs were analyzed through multivariate analysis of variance while multinomial regression analysis was used to identify factors that influ-ence their perception of the performance. The results reveal significant differences in performance scores among FMGs. Members of some FMGs perceived that the participatory forest management program ena-bled them to get benefits from the sale of fuelwood while performance scores in the forest conservation and decision-making processes is gener-ally poor. The score for economic performance of FMGs in turn was related to better access to roads and markets. Group size tended to en-hance economic performance via its strong influence on annual fuelwood harvest, while the resource base appeared to be inconsequential. Mem-bers of the forest management groups perceived that large group size and group heterogeneity, particularly in terms of ethnicity, as well as knowledge and awareness of problems related to the forest environment have no influence on the performance of their respective groups. For rural communities to have a favorable disposition toward sustainable forest management, differences in member understanding of collective actions and their impact before and during the implementation of partic-ipatory forest management programs should be considered.

关键词： Common-pool resources Collective action Sustainableforest management West Africa

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Coppicing ability of dry miombo woodland species harvested for traditional charcoal production in Zambia:a win–win strategy for sustaining rural livelihoods and recovering a woodland ecosystem

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Journal of Forestry Research 2017年第3期28卷 549-556页

作者： Stephen Syampungani mulualem tigabu Nalukui Matakala Ferdinand Handavu Per Christer Oden School of Natural Resources Copperbelt UniversityBox 21692KitweZambia Southern Swedish Forest Research Centre Swedish University of Agricultural SciencesBox 49230 53 AlnarpSweden Zambia Forestry College P/Bag MwekeraKitweZambia

The miombo woodland is one of the most extensive woodlands in Africa, supporting livelihoods based on biomass fuel for millions of rural people. However, there are growing concerns about the sustainability of harvesting for biomass fuel （mainly charcoal）. Thus, the aim of this study was to examine whether regeneration by coppice is a viable option for sustainably managing miombo woodlands for biomass fuel production. We tested the hypotheses that （1） species, stump diameter, stump height and time since cutting significantly affect the number of sprouts per cut stump （coppice density） and mean sprout height （shoot vigour） and （2） higher coppice density reduces shoot vigour due to competition among coppice shoots in a given stump. In an inventory in areas that were harvested for charcoal production by the local people, 369 stumps of 11 species were recorded with mean coppice stumps ranged from 6 to 84. The mean coppice density ranged from 5 to 8 shoots per stump while the mean height of coppice shoots ranged from 46 to 118 cm with marked interspecific variations. Stump size was signifi- cantly and positively correlated with coppice density for some of the species, but not with shoot vigour for the majority of the species. However, shoot vigour was significantly positively correlated to time since cutting of trees for nearly half of the species. Coppice density had a significant negative correlation with shoot vigour for two species, and a positive correlation for one species. In conclusion, the results provide evidence about the importance of coppice management as a win-win strategy for sustaining charcoal-based rural livelihoods and recovering the miombo woodland ecosystem.

关键词： African woodlands Charcoal production Forest management Regeneration Resprouting ability

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Growth characteristics and reproductive output of dwarf mistletoeinfected Juniperus polycarpos in Iran

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Journal of Forestry Research 2014年第4期25卷 827-834页

作者： Abolfazl Daneshvar mulualem tigabu Asaddollah Karimidoost Mostafa Farhadi Per Christer Odén Swedish University of Agricultural Sciences Southern Swedish Forest Research Centre P.O Box 49 SE-230 53 Alnarp Sweden Department of Natural Resources Gonbad Kavous University Shahid Fallahi Street PO BOX: 163 Gonbad Iran Agriculture and Natural Resources Research Center of Golestan Province Beheshti Ave. PO Box *** Gorgan IRAN

Dwarf mistletoes are parasitic flowering plants that infect conifers, resulting in substantial loss of growth and mortality. Recently, forest managers in Iran are contemplating whether infection of Juniperus polycarpos C. Koch forests by dwarf mistletoe, Arceuthobium oxycedri （DC.） M. Bieb, influences tree vigor and contributes to insuffieient natural regeneration. The present study aimed at assessing the severity of infection and its impact on growth and reproductive output of./., polycar- pos. Infected and uninfected trees （n =20 each） were selected for assess- ment of diameter, height, crown area, and crown volume as well as quantity and quality of cones and seeds. The severity of infection of trees was determined by Hawksworth＇s 6-class dwarf mistletoe rating （DMR） system. The DMR system revealed that 40% of the infected sample trees were lightly infected （DMR =1-2） and 60% were moderately infected （DMR =3--4）. Growth characteristics did not differ significantly （p 〉 0.05） between infected and uninfected trees. However, moderate infec- tion affected the reproductive output of./. polycarpos by significantly （p 〈0.05） reducing the mean number of cones per unit area of the crown, increasing the number of damaged seeds, and reducing seed size and seedgermination capacity. We conclude that reproductive output of J.. poly- carpos is more sensitive than growth characters to moderate infection by juniper dwarf mistletoe, and this might partly account for poor natural regeneration.

关键词： conifers Greek juniper forest health parasitic plant seed size

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Longevity of Juniperus procera seed lots under different storage conditions: implications for ex situ conservation in seed banks

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Journal of Forestry Research 2011年第3期22卷 453-459页

作者： Negash Mamo Diriba Nigusie mulualem tigabu Demel Teketay Miftah Fekadu Ethiopia Agricultural Research Organization Forestry Research Centre P.O.Box 30708 Addis Ababa Ethiopia Swedish University of Agricultural Sciences Southern Swedish Forest Research Centre Tropical Silviculture and Seed Laboratory PO Box 101 SE-230 53 Alnarp Sweden University of Botswana Okavango Research Institute Private Bag 285 Maun Botswana

Juniperus procera Endl. is economically important timber species, but its populations are extremely small and fragmented in its natural habitat, thus, calling for immediate ex situ conservation. Here we examined the effects of seed sources and storage temperature on the longevity of Juniperus procera seed lots through collection and preservation of seeds in seed banks. Seeds were collected from nine sites across the species natural distribution in Ethiopia and stored in four warehouses： modern cold room （5℃）, mud house （15℃）, concrete block house （17℃ or corrugated iron house （20℃） for 42 months. Every three months, a random sample of stored seeds were drawn and tested for germination. A highly significant variation （p 0.01） in germination of stored seeds was observed among different storage environments, seed lots, and duration of storage. Over the storage period, seeds stored in the cold room had the highest mean percentage germination, followed by the mud house, corrugated house and blocket house. The cold room （41%） and the mud house （38%） maintained the same level of germination as the intitial germination of the seedlotds （42%）. The variation in longevity of stored seeds was significnatly correlated with the initial germination of seed lots （r 0.80; p 0.01）. Cold storage also resulted in enhancement of germination through its stratification effect that terminated the non-deepphysiological dormancy of juniper seeds. In conclusion, seed lots with good initial germination can be effectively stored in cold room （5℃） up to four years. In the absence of modern cold stores, mud houses can be used as a good alternative to store seeds at local level.

关键词： germination African pencil cedar Ethiopia seed zones seed storage

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Progresses in restoration of post-mining landscape in Africa

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Journal of Forestry Research 2019年第2期30卷 381-396页

作者： Emma Sandell Festin mulualem tigabu Mutale N.Chileshe Stephen Syampungani Per Christer Oden Southern Swedish Forest Research Centre Swedish University of Agricultural Science School of Natural Resources Department of Plant and Environmental Sciences Copperbelt University

Mining alters the natural landscape and discharges large volumes of wastes that pose serious pollution hazards to the environment, to human health and to agriculture. As a result, the recent 2 decades have witnessed a global surge in research on post-mining landscape restoration, yielding a suite of techniques including physical, chemical, biological(also known as phytoremediation) and combinations. Despite the long history of mining in Africa, no systematic review has summarized advances in restoration research and practices after mining disturbance. Thus, the aim of this review was to document the state-of-knowledge and identify gaps in restoration of postmining landscape in Africa through literature review. We found that:(1) there has been substantial progress in identifying species suitable for phytoremediation;(2) few studies evaluated the feasibility of organic amendments to promote autochthonous colonization of mine wastelands or growth of planted species; and(3) restoration of limestone quarries in Kenya, sand mining tailings in South Africa,and gold mine wasteland in Ghana are successful cases of large-scale post-mining restoration practices in ***, the pace of post-mining landscape restoration research and practice in Africa is sluggish compared to other parts of the global south. We recommend:(1)mainstreaming the restoration of mine wastelands in national research strategies and increased development planning to make the mining sector ‘‘Green'';(2) inventory of the number, area, and current status of abandoned mine lands;(3) expanding the pool of candidate species for phytostabilization;(4) further evaluating the phytostabilization potential of organic amendments, e.g., biochar;(5)assessing the impacts of mining on regional biodiversity.

关键词： Phytoremediation Phytostabilization Reclamation Remediation Tailing dams

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Pre-sowing treatment for breaking dormancy in Acer velutinum Boiss. seed lots

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Journal of Forestry Research 2013年第2期24卷 273-278页

作者： Mostafa Farhadi mulualem tigabu Alireza Ghasemi Arian Mehdi Sharifani Abolfazl Daneshvar Per Christer Oden Swedish University of Agricultural Sciences Southern Swedish Forest Research Centre Education Center of Jihad-Agriculture Gorgan University of Agricultural Sciences and Natural Resources Horticulture Department

Acer velutinum Boiss is a valuable tree species native to Iran, and its seeds possess physiological dormancy that hampers seedling production in the nursery for large-scale reforestation efforts. The aim of this study was to determine the optimal dormancy breaking treatments for A. velutinum seeds. We conducted a factorial experiment involving six seed lots collected along an elevation gradient from 300 to 1800 m at 300 m interval and four cold-moist stratification periods （0, 4, 8 and 16 weeks） at 4℃ and 70% relative humidity. The result shows that the germination of cold-moist stratified seeds was significantly （p 〈 0.0001） higher than the control for all seed lots. The highest germination capacity was recorded after 16 weeks of cold-moist stratification for all seed lots （68% 88% depending on the seed lot） except those collected from mid altitude sites （600 and 900 m） that germinated equally well （≥ 75%） after 4and 8-week of clod-moist stratification compared to the other seed lots. The mean germination time was significantly shorter （12 to 19 days, depending on the seed lot） for seeds stratified for 16 weeks than for untreated seeds. It can be concluded that：（1） cold-moist stratification for 16 weeks is the best pre-sowing treatment for breaking dormancy in A. velutinum seeds; and （2） seeds should be collected from mid altitude sites （600 and 900 m） to get more than 80% germination within 15 days, and these seed lots even required shorter cold-moist stratification period（eight weeks） than other seed lots.

关键词： cold-stratification altitude physiological dormancy velvet maple seed germination

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Picea species from humid continental and temperate marine climates perform better in monsoonal areas of middle latitudes of China

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Journal of Forestry Research 2021年第4期32卷 1395-1408页

作者： Fangqun Ouyang Jianwei Ma Junchen Wang Lisheng Kong Hanguo Zhang mulualem tigabu Junhui Wang State Key Laboratory of Tree Genetics and Breeding Key Laboratory of Tree Breeding and Cultivation of State Forestry AdministrationResearch Institute of ForestryChinese Academy of ForestryBeijing 100091People’s Republic of China Research Institute of Forestry of Xiaolong Mountain Gansu Provincial Key Laboratory of Secondary Forest CultivationGansuPeople’s Republic of China Beijing Botanical Garden Beijing Floriculture Engineering Technology Research CentreBeijing Laboratory of Urban and Rural Ecological EnvironmentBeijingPeople’s Republic of China Department of Biology Centre for Forest BiologyUniversity of VictoriaVictoriaBCCanada State Key Laboratory of Tree Genetics and Breeding Northeast Forestry UniversityHarbin 150040People’s Republic of China Swedish University of Agricultural Sciences Southern Swedish Forest Research CenterBox 4923053 AlnarpSweden

Picea *** a prominent component of the boreal,montane,and sub-alpine forests in the Northern Hemisphere,and have substantial economic importance due to their high quality ***,performance and wood properties of the genus have not been systematically evaluated in *** study aimed to examine genetic variations in growth traits,phenology,and wood properties of 17 Picea species,(three from North America,two from Europe,and 12 from China),in response to specific climate factors using a randomized complete block design in a monsoonal,middle latitude area of *** show that all growth traits and wood properties significantly varied among species(P <0.00).Of the 17 species examined,*** and *** were the tallest with heights of 2.5 and 1.9 m at 9 years old,respectively,90% and 50% greater than the average *** length,number,and angles of both *** and *** were greater than those of the other *** of *** and *** were20-33% greater than the ***-growing species had high quantities of first lateral branches and large top whorl branch *** taller species exhibited greater tracheid lengths and average tracheid lengths to radial central diameter ratios(TL/R_D2),but smaller cell wall thicknesses to tracheid radial lumen diameter ratios(WT/R_D1),which is favorable for pulp *** analysis revealed that height and ring width had significant positive correlations with latitude but strongly negative correlations with *** was positively correlated with average annual rainfalls,but negative correlations with average yearly *** to the increased average annual sunshine at the China test site relative to the seed source,species such as ***,***,***,and *** from wet,humid areas performed better than native *** similar temperatures,precipitation may be the main factor affecting growth,which is beneficial for predicting the extent

关键词： Climate Growth performance Genetic variations Picea Wood properties

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Within-and between-population variations in seed and seedling traits of Juglans mandshurica

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Journal of Forestry Research 2022年第4期33卷 1175-1186页

作者： Qinhui Zhang Shihe Yu Xiaona Pei Qianchun Wang Aijun Lu Ying Cao mulualem tigabu Jian Feng Xiyang Zhao State Key Laboratory of Tree Genetics and Breeding Northeast Forestry UniversityHarbin 150040People’s Republic of China Liaoning Academy of Forest Science Shenyang 110032People’s Republic of China State Administration of Forestry and Grassland Harbin Research Institute of Forestry MachineryHarbin 150086People’s Republic of China Research Center of Cold Temperate Forestry CAFHarbin 150086People’s Republic of China Forestry Development and Service Center of Liaoning Shenyang 110032People’s Republic of China Southern Swedish Forest Research Centre Swedish University of Agricultural SciencesPO Box 4923053 AlnarpSweden

In order to quantify within-and between-population variation in seed and seedling traits of Juglans mandshurica and reveal the relationship among genetic and environmental variations and select elite families,samples of 50 *** families from five natural populations in Liaoning Province,northeast China,were taken to measure seed and seedling *** results show that all seed traits varied significantly among families within the population,but only kernel weight and kernel rate showed significant variations among *** values of single seed weight,length,width,lateral diameter,and average size,and kernel weight and rate were 10.1 g,43.0 mm,29.2 mm,28.1 mm,33.4 mm,and 2.2 g and 22.5%,*** variations were observed in seedling height and root collar diameter among families and interaction between families and blocks,but the block effects on height and root collar diameter were *** values of height and root collar diameter were 94.0 cm and 8.7 mm,*** heritability of traits ranged from 0.6 gm(kernel weight)to 0.9 mm(seedling height).Correlation analysis showed a strong relationship among seed traits but a weak correlation between seed and seedling *** analysis grouped the five natural populations of *** into three significant clusters with different *** general combining ability analysis showed that most traits in one family(WD11)were higher,suggesting parental traits were excellent for selecting elite parent *** the comprehensive evaluation method,five families with better seed traits and five families with better seedling traits were selected as elite materials with 10%selection *** genetic gains of these elite materials for seed weight,kernel weight,average seed size,kernel rate,seedling height,and root collar diameter were 13.1%,10.3%,4.1%,2.4%,29.7%,and 21.1%,respectively.

关键词： General combining ability Heritability Comprehensive evaluation Genetic gain

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