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The influence of tree species on forest soils has been the subject of study for at least a century. Of particular interest have been western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don) – two of the most common tree species in coastal and southern British Columbia, but each with a different nutrient amplitude. It has generally been found that acid, mycogeneous Mor humus forms develop in hemlock stands, while less acid and more zoogenous Mormoder, Moder, or even Mull humus forms develop in redcedar stands. The objective of this study was to determine the influence of hemlock and redcedar, growing separately and together, on forest floor nutrient properties. The questions addressed were: (1) does each stand type have unique forest floor nutrient properties? and (2) can any forest floor nutrient property discriminate between stand types?

Thesis (MS en S)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Informal street trading is an aspect with which South Africa's ever growing cities need to cope. Since the earliest times, trade has played an important role in creating livelihoods for many people. In today's society - characterised by unemployment and underdevelopment - informal street traders have recognised that there is a gap in the market, and thus, by plying their trade they created a sustainable livelihood for themselves. It has to be admitted that town planning over the years neglected the role of the informal street trader, and not much was done by way of creating a city sphere to accommodate the street trader. In chapter two of this study the discussion addresses the historical role and activities of the informal street trader, and surveys aspects of legislation and racism that played a prominent role in previous times. Authorities did not regard informal trading in a positive light and many harsh steps were taken against street traders. This provides one of the reasons why no latitude was granted to informal street trading and why South Africa's existing efforts to accommodate informal street trade could at best be described as dismal. In chapter three the role and extent of informal trading in the economy is discussed. A study was made of the possible reasons why the informal street trade has emerged, and the contribution of the informal trade towards South Africa's Gross Domestic Product, is also dealt with. Today informal street trade is viewed as one of the ways by means of which to alleviate South Africa's existing employment crisis and accommodation of the informal street trade is seen as a top priority. When considering the phenomenon of informal street trading, it is impossible to ignore the people who are involved in this sector. They have created not only jobs for themselves, but a sustainable way of living. Chapter four attends to the characteristics of the informal street trader and also addresses the problems and challenges that these people have to face. Addressing these problems or challenges is not an easy task, and one of-the major problems in this respect has been the question of legislation. Informal street trading needs to be directed through laws and policies, aimed at addressing traders' needs and which are proactive in creating a positive trading environment. In chapters five and six the legislation and regulation of informal street trading in three of South Africa's major metropolitan cities - Cape Town, Port Elizabeth and Durban - are reported. Chapter seven contains the conclusions of the study, followed by some policy recommendations. These are based on the findings made in the study on informal street trading, and could possibly enhance the proactive control and development of informal street trading. / AFRIKAANSE OPSOMMING: Informele straathandel is 'n verskynsel wat volop in Suid-Afrikaanse stede voorkom. Handel is verantwoordelik vir die skep van werksgeleenthede en in vandag se samelewing, wat gekarakteriseer word deur armoede en werkloosheid, bied informele straathandel 'n uitweg aan menige persone om In bestaan te voer. Deur die jare het stadsbeplanning nie die nodige aandag aan die informele straathandelsektor gegee nie en meeste Suid-Afrikaanse stede kan nie hierdie tipe aktiwiteit suksesvol akkommodeer me. In hoofstuk twee van hierdie studie word daar ondersoek ingestel na die historiese agtergrond en aktiwiteite van die informele straathandelaar en word kwessies soos wetgewing en rasisme aangespreek. Owerhede het tydens die vorige bedeling nie die straathandel as 'n positiewe aspek van Suid-Afrika se groeiende stede beskou nie en sterk maatreels is teen straathandelaars gene em. Weens hierdie stappe en aksies, het dit gelei tot 'n stedelike omgewing wat nie straathandelaars vandag kan akkommodeer nie, en word dit ook as die rede beskou waarom huidige pogings tot die akkommodasie van straathandel nie as besonder suksesvol beskou kan word nie. In hoofstuk drie word die rol en mate waartoe informele straathandel tot die land se ekonomie bydra, bespreek. Die moontlike redes is ondersoek om die ontstaan van die informele straathandelsektor te identifiseer, en ook is gekyk na die bydraes wat die straathandel tot Suid-Afrika se Bruto Binnelandse Produk maak. Vandag word die informele straathandel as 'n moontlike oplossing vir armoede en werkloosheid in Suid- Afrika beskou en word die ontwikkeling van die sektor as 'n top prioriteit hanteer. Daar is ook ondersoek ingestel na die mense wat betrokke is in informele straathandel. Hierdie deel van die bevolking was in staat om op 'n volhoubare manier werk vir hulself te skep. Hoofstuk vier stel ondersoek in na die kenmerke van die informele straathandelaars en kyk ook na die daaglikse probleme en uitdagings wat hierdie mense beleef. Om hierdie probleme en uitdagings te bowe te kom, is nie eenvoudig nie, maar die grootste probleem vir straathandelaars spruit voort uit wetgewing oor die sektor. Informele straathandel benodig rigtinggewende w.etgewing en beleid wat die sektor se behoeftes en probleme aanspreek en ook 'n positiewe omgewing vir die straathandelaars skep om in te werk. Hoofstukke vyf en ses stel ondersoek in na die bestaande wetgewing oor informele straathandel, soos dit aangetref word in drie van Suid-Afrika se grootste stede, Kaapstad, Port Elizabeth en Durban. In hoofstuk sewe word die gevolgtrekking en beleidsvoorstelle rondom die bevindings van die studie gemaak. Dit sal dan moontlik lei tot die bevordering en skep van 'n gunstige en pro-aktiewe omgewing waarbinne informele straathandel kan floreer.

Tirti Utenos miškų urėdijos pušynai, kuriuose 2003 ir 2006 m. buvo užfiksuoti pažeminiai miško gaisrai. Tyrimo tikslas nustatyti gaisrų padarytą poveikį metinio radialiojo prieaugo augimui. Duomenų surinkimui naudota dendrochronologinių tyrimų duomenų rinkimo metodika. Surinti duomenys išanalizuoti CHRONOL programa. Tyrimais įrodyta, kad gaisrai daro neigiamą įtaką pušynų radialiojo prieaugio augimui. / The research material for dendrochronological analysis was collected in forest area located in Utena Forest Enterprise. The objects of study were as follows: 40 year-old Vaccinium Pinetum one-layer stands, quality class – II. In two objects forest fires were in 2003 and in other two – 2006. Also, one object was selected as control where fire has not been observed. To estimate the influence made by fire to tree (Pinus sylvestris L.) radial increment, samples were taken ussing Pressler age borer in accordance with the methods for collecting experimental material of dendrochronological research work (Stravinskiene, 1994). To measure annual radial increment and estimate tree ring structure, the samples were examined by LINTAB tree-ring measurement system and TSAP computer programme. The COFECHA programm was used for analyzing obtained primary data. Using the COFECHA programme we performed cross-dating quality control. Annual tree-ring width series of asynchronous growth or lagged correlation were rechecked, corrected or eliminated from the next stages of the research with the master chronology approach. To determine impact of fire to stand growth conditions upon Pinus Sylvestris L. radial increment dendrochronological research work, dendrochronological scales of the stands with former observed fires and control stand was carried out. Well-defined decrease of radial increment was ascertained. Fire presence makes significant impact of annual radial increment dynamic after it’s... [to full text]

Baigiamajame darbe tiriama, kokią įtaką daro skirtingos medžių rūšys dirvožemio rūgštingumui. Darbo objektas – ASU medynų parkas. Darbo tikslas - Šio tyrimo tikslas yra nustatyti, kaip skirtingos medžių rūšys pakeitė dirvožemio pH reakciją medynuose, kuriuose medžiai auga 50 – 56 metus. Darbo metodai – skirtinguose dirvožemio gyliuose pH reakcijos nustatymas lauko ir laboratorijos sąlygomis, karbonatų putojimo gylio nustatymas lauko sąlygomis. Darbo rezultatai. Medynų dirvožemio pH reakcija priklauso nuo augančių medžių rūšių. pH-metru gauti duomenys parodė, kad apie pusės medynų dirvožemio reakcija buvo labiau šarminė nei pievos dirvožemio. H2O ir CaCl2 tirpaluose nustatytos pH reakcijos gautos rūgštinės, tačiau ne visos. H2O tirpale šarminė reakcija gauta paprastosios pušies, neutrali – plaukuotojo beržo ir mažalapės liepos medynų dirvožemiuose. Didžiausią paklotę ir nuokritų masę suformavo hibridinio maumedžio medynas. Visi kiti medynai suformavo daug mažesnes paklotes. Dirvožemio rūgštingumo didinime nerasta ryšio nei tarp svetimkraščių bei vietinių medžių rūšių, nei tarp lapuočių bei spygliuočių. / Subject of the research – This thesis was started in order to investigate what influence on soil acidity has different tree species. Investigation was held in the stand park belonging to Aleksandras Stulginskis University. Aim of the research - Thesis aims to investigate how different tree species has changed soil pH reaction in stands of 50 – 56 years old. Methodology – pH reaction's identification in out doors and lab conditions in different depth levels of soil, depth identification of carbonate foaming in out door conditions. Results. The investigation revealed that soil pH is mostly depending on growing tree species. Using pH meter it was estimated that soil reaction under half of the stands was more alkaline than in grasslands. A reaction in H2O and CaCl2 solutions was found to be acid, however not in all samples. In H2O solution reaction was alkaline for pine (Pinus Sylvestris) while neutral for birch (Betula pubescens) and lime tree (Tilia cordata) stands soils. The thickest litter and biggest mass of litter fall was formed under hybrid larch stands. Other stands formed much lower litter, therefore it could not be stated that litter fall of all tree species has impact on soil acidity. There was found no correlation in increasing soils’ acidity between native and introduced tree species as well as broadleaves and coniferous.

2001 skedde ett kraftigt utbrott av Gremeniella abietina (Lagerb.) M. Morelet i området Bergvik, Dalarna. Skogsägarna var tvungna att avverka kraftigt i deras tallbestånd som respons på detta. I de objekt som återplanterades planterades det nya artsammansättningar än vad som planterats tidigare, gran och blandbestånd av gran och tall. I denna studie jämfördes och inventerades medelhöjderna på de återplanterade objektens träd för att skatta arternas framgång i de olika ståndorterna. Gran verkade vara mest lämpat eftersom den växte signifikant bättre än vad tillväxtekvationerna hade förutspått. Det påträffades även en positiv blandskogseffekt på trädens medelhöjd i provytorna. Provytor med högre antal arter, hade gran och tall med högre medelhöjd än artfattigare provytor. Provytor med tre arter, björk gran och tall hade högre tillväxt än provytor med endast tall och gran. Graden av inblandning i hela objektet hade inte någon signifikant effekt på medelhöjden. Detta tyder på att den spatiella artsammansättningen har större betydelse för de positiva effekterna av blandskog än artsammansättningen inom ståndorten i sin helhet. Detta antas vara på grund av nisch-komplementering och facilitering, möjligtvis via mykorrhiza interaktion. En annan möjlig förklaring är den minskade intra-specifika konkurrensen när individer av samma art är planterade med större avstånd sinsemellan. Troligtvis beror det på en nischuppdelning som tillåter de olika trädarterna att utnyttja markens tillgångar effektivare. Detta indikerar att småskalig artsammansättning är av vikt för tillväxten hos gran och tall. / In 2001 there was a serious outbreak of Gremmeniella abietina (Lagerb.) M. Morelet in the municipality of Bergvik in Dalarna, Sweden. The forest owners were forced to effectively cut their Pine stands in an attempt to halt the onslaught of the fungus. In the areas where new trees were planted after the cuttings, different compositions of species were implemented. Instead of only Pine (Pinus sylvestris), most of the new plantations consisted of spruce (Picea abies) or mixtures of the two species. In this study the average height of these replanted trees was measured to assess the success that the different species had in the different replanted areas. Spruce seemed to be the species that was best adapted to the local area because it grew significantly higher then what had been predicted. A positive effect of mixed-stands was also observed. The sample areas with three species, pine, spruce and birch (Betula pendula) had a higher average height then the sample areas that contained less species. The degree of mixture in the plantation as a whole had no significant effect on tree height. This implies that the spatial composition of species is of bigger importance then the quota of different species in the whole plantation. This could be explained by niche-complementation and by facilitation, probably via interactions between mykorrhiza. Intra-specific competition is another possible explanation for the greater height in sample areas with more species.  Most likely because a decrease in intra-specific competition allows a division of niches and therefore permits the resources in the soil to be utilized more efficiently. The implication of this being that small-scale specie composition is of importance.

Os riscos de diminuição dos teores de matéria orgânica e nitrogênio no solo são elevados em povoamentos monoespecíficos de eucaliptos. Uma das alternativas para contornar ou reverter este problema é o plantio misto de eucalipto com leguminosas arbóreas fixadoras de N2. O presente estudo teve como objetivo avaliar as interações entre espécies no crescimento da parte aérea e do sistema radicular, na nutrição mineral das plantas e na fixação de nitrogênio em plantios consorciados de e leguminosas arbóreas. O estudo foi conduzido na Estação Experimental de Ciências Florestais de Itatinga, Itatinga, SP. O tipo de solo ocorrente na área foi caracterizado como Latossolo Vermelho-Amarelo Distrófico psamítico. O clima foi caracterizado como mesotérmico úmido (Cwa), segundo a classificação de Köeppen. O delineamento experimental foi o de blocos ao acaso com 3 repetições. As parcelas experimentais tinham 100 plantas, de E. grandis estabelecidas no espaçamento de 3,0m x 3,0m. Nas linhas de plantio, no meio do espaço entre as plantas de E. grandis, foram plantadas intercaladamente (50% da população do E. grandis leguminosas arbóreas nativas de matas brasileiras (Peltophorum dubium, Inga sp, Mimosa scabrella, Acacia polyphylla, Mimosa caesalpiniaefolia) e uma leguminosa exótica (Acacia mangium). O experimento foi medido até os 24 meses pós-plantio. A M. scabrella e a A. Mangium foram às leguminosas que tiveram maior crescimento. O E. grandis, consorciado com a M. scabrella cresceu menos porém, foi o consórcio mais produtivo. Quanto a densidade de raízes finas (drf), para o E. grandis, esta só variou na camada de 0-30cm de profundidade enquanto que para a M. scabrella e a M. caesalpiniaefolia as variações de drf ocorreram logo abaixo dessa camada. Isso indica que estas leguminosas procuraram explorar camadas onde a competição com o E. grandis era menor. A A. mangium e a M. caesalpiniaefolia apresentaram as menores drf (< 0,3 cm cm-3). A M. scabrella apresentou maior drf, a qual chegou a 0,84 cm cm-3 aos 24 meses. Apenas o consórcio E. grandis mais M. scabrella apresentou maior acúmulo de N na soma de todos os seus compartimentos em relação ao povoamento solteiro de E. grandis. Proporcionalmente, as quantidades de N acumuladas na biomassa da M. scabrella, da M. caesalpiniafolia e da A. mangium foram maiores do que no E. grandis. A M. scabrella foi bem mais eficiente do que as demais leguminosas para incorporar N na biomassa aérea. O E. grandi acumulou mais N nas folhas do que no lenho, ao contrário do que foi observado para a M. scabrella e a M. caesalpiniafolia. Pela análise isotópica foi constatado que a M. scabrella possui maior eficiência para fixar N2 atmosférico do que as outras espécies de leguminosas. Dentre as leguminosas nativas, esta espécie foi a que demonstrou maior potencial para uso em plantios consorciados. / The risks of reduced organic matter content and soil nitrogen are elevated in pure stands of eucalypt. One of the alternatives to avoid or solve this problem is the use of mixed plantation of eucalypt with leguminous N2-fixing trees. The objective of the present study was to evaluate the above and belowground growth interactions between species, the mineral nutrition of the plants and nitrogen fixation in mixed stands of E. grandis and native leguminous N2-fixing trees. The study was carried out at the Experimental Station of Forest Sciences of Itatinga, Itatinga, São Paulo, Brazil. The soil was characterized as loam Red-Yellow Latosol. The climate is characterized as humid mesothemic according to the classification of Köeppen. The experimental design was in 3 blocks with each block having 7 parcels. The experimental parcels had 100 plants of E. grandis established with the space of 3,0m x 3,0m. Within the lines of the E. grandis seedlings (50% of the population of the E. grandis) was intercropped with native leguminous N2-fixing trees (Peltophorum dubium, Inga sp, Mimosa scabrella, Acacia polyphylla, Mimosa caesalpiniaefolia) and one exotic leguminous plant (Acacia mangium). The experiment was evaluated for 24 months after planting. The M. scabrella and A. mangium are the legume trees that had highest growth. Although E. grandis and M. scabrella had the lowest growth, it was the most productive combination. The fine root density of E. grandis only varied in the layer of 0-30cm deep whereas for the M. scabrella and the M. caesalpiniaefolia the root density variations occurred below this layer. This indicates that these legume trees explore layers where competition with E. grandis is least. A. mangium and M. caesalpiniaefolia produced the lowest root density (< 0,3 cm cm-3). The M. scrabella produced the highest root density of 0,84 cm cm-3 within 24 months. E. grandis and M. scabrella was the only combination that had the highest accumulation of N in relation to all evaluated compartments of the pure stand of E. grandis . Proportionally, the amounts of accumulated N in the biomass of M. scabrella, M. caesalpiniafolia and A. mangium was higher than E. grandis. M. scabrella was the most efficient legume tree in incorporation of N in the above and belowground biomass. E. grandis accumulated more N in the leaves than in the stems contrary to what was observed in M. scabrella and M. caesalpiniafolia. . Using the isotopic analysis it was observed that M. scabrella had greater efficiency in fixing atmospheric N2 than the other species of leguminous trees. Amongst the native leguminous trees, M. scabrella was the one that demonstrated a greater potential for use in mixed stands.

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Magistro darbe tiriama 2010 m. 08 mėn. praūžusios audros padariniai Varėnos miškų urėdijos Glūko girininkijoje. Darbo objektas – Varėnos miškų urėdijos Glūko girininkijos vėjavartų pažeisti medynai. Darbo tikslas – Ištirti 2010 m. audros padarinių išplitimą bei atlikti pažeistų medynų kiekybinių rodiklių analizę Varėnos miškų urėdijos Glūko girininkijoje. Darbo metodai – Panaudojus planinę medžiagą bei GIS miškų žemėlapį, natūroje buvo patikslintos vėjavartų pažeidimų apimtys. Vėliau, vadovaujantis inventorizacine medžiaga, buvo įvertintas pažeistų medynų plotas. Tyrimams naudoti 414 medynų dendrometriniai rodikliai: rūšinė sudėtis, amžius, vidutinis aukštis, skalsumas ir augavietė. Minėti rodikliai buvo grupuojami, apdorojami MS Excel programa. Nesutvarkytuose po vėjavartų 6 medynuose atrankinės apskaitos metu įvertinta sanitarinė būklė. Darbo rezultatai. Varėnos miškų urėdijos Glūko girininkijoje 2010 m. 08 mėn. audra pažeidė 1361,3 ha miškų (41,5 % visų miškų). Didžiausi pažeidimai grynuose (9 –10 P), pusamžiuose (65,9 %), 0,8 – 0,9 skalsumo (64,7 %) pušynuose, augančiuose Nb augavietėje (89,5 %). Pažeistų pušynų vidutinis aukštis 16 – 20 m. Vėjavartos juodalksnynuose sudarė 1.1 %, beržynuose 0,8 %, eglynuose 0,5 % ir liepynuose 0,1 %. 2011 m. buvo įvertinta pušynų sanitarinė būklė atsitiktinai pasirinktuose 6 nuo pažeistuose bei vienerius metus netvarkytuose medynuose, kuriuose buvo numatyti atlikti plynuosius ir neplynuosius sanitarinius kirtimus. Medynuode kur buvo... [toliau žr. visą tekstą] / The main purpose of this master thesis is to evaluate the influence of August 2010 storm in Varėna‘s Enterprise, Glūko‘s foreststry. Study object: demaged stands in Varėna‘s Enterprise, Glūko‘s foreststry. Study aim: to investigate the consequences of August 2010 storm and perform quantitative analysis of damaged stands in Varėna‘s Enterprise, Glūko‘s foreststry. Methodology: Volume of windfalls were adjusted using cartographic material and GIS map of forests. Then, according to forest inventory database, damaged area was assessed. 414 dendrometric indicators were used: species composition, age, average height, stocking level and sites. These indicators were grouped, processed by MS Excel. Sanitary conditions were evaluated within sample plots established in 6 indisposed stands. Results. 1361,3 ha (41,5 % of total forests) of forests were damaged in Varėna‘s Enterprise, Glūko‘s foreststry by August 2010 storm. Pure (9 – 10 P), middle-aged (65,9 %), 0,8 – 0,9 stocking level (64,7 %) pinewoods in Nb sites (89,5 %) were the most damaged. Middle height of pinewoods – 16 – 20 m. 1,1 % of alder woods, 0,8 % of birch woods, 0,5 % of fir woods and 0,1% of linden woods were damaged. Sanitary conditions were investigated in 6 randomly selected stands, which were damaged by storm and planned clear-cut and non-clear cut. Trees’ condition was evaluated in 12 classes of sanitary. 4 – 16 % relatively healthy, 8 – 13 % damaged and 70 – 88 % destroyed trees were indentified in plots, where... [to full text]