No description available.

Global and local climate patterns may affect barren-ground caribou (Rangifer tarandus groenlandicus) populations. I predicted global climate changes to be correlated with periods of population decline, and local changes to be more pronounced on the habitat of caribou with a declining population. In chapter 1, the Arctic Oscillation (AO), changes in normalized difference vegetation index and phenology were used as measures of global and local climate. In chapter 2 environmental variables and caribou presence points were used to build Maxent habitat models. There was no consistent correlation with the positive AO phase and periods of population decline, or phenology trends and the habitat of caribou with a declining population. Maxent models underestimated the amount of suitable habitat spatially and failed to model suitable habitat temporally. This thesis is the first to look at a range of density-independent variables over a long time period and model suitable habitat for multiple herds.

Canada is the second highest producer of hydroelectric energy in the world. Nearly 50 of the hydroelectric reservoirs in the country have a capacity larger than 1 billion m3. Despite the great number and extent of hydropower developments in Canada and around the world, relatively little is known about how dams and their operations influence terrestrial and semi-aquatic wildlife. Reservoirs at northern latitudes are characterized by large fluctuations in water level, which create modified shorelines called drawdown zones. To evaluate the impact of these disturbances on amphibians and reptiles, I conducted visual encounter surveys at two sites in the drawdown zone of Kinbasket Reservoir, near Valemount, B.C. From April to August of 2010 and 2011, I documented the habitat use, reproductive phenology, and body condition of two amphibian species (Anaxyrus boreas and Rana luteiventris) as well as the growth, movements, diet, and distribution of one species of garter snake (Thamnophis sirtalis). At two sites in the drawdown zone, A. boreas and R. luteiventris were present for the duration of the summer and utilized several ponds for reproduction. The presence and abundance of Rana luteiventris eggs were generally associated with ponds that had higher mean temperatures, higher mean pH, and the presence of fish. In 2010, there was sufficient time for amphibian breeding and metamorphosis to occur before the reservoir inundated the drawdown zone, but low precipitation levels in that year led to desiccation of many breeding ponds. In 2011, high rainfall and snowmelt led to early inundation of breeding ponds, and thousands of tadpoles were presumably swept into the reservoir. Gravid Thamnophis sirtalis were found at just one of two sites in the drawdown zone, but both sites were frequented by foraging individuals of this species. Anaxyrus boreas appears to be the primary prey of T. sirtalis in the drawdown zone. An improved understanding of how the amphibians and reptiles at Kinbasket Reservoir have persisted in this highly disturbed environment may be vital to their conservation — the activation of a new generating unit at Mica Dam in 2014 will alter the pattern and timing of reservoir inundation for the first time since it was constructed 40 years previously. / Graduate

Turkey is on the main migratory route for many bird species although especially passerine migration is little known. The objective of this study is to document and analyze the diversity, abundances, daily and seasonal phenologies of migrating passerines at METU as well as compare seasonal phenologies with those obtained at Manyas KuScenneti(Balikesir) and Cernek(Samsun) stations. The study covers autumn 2001, spring and autumn 2002 migration seasons. Methodology is based on the capture and ringing of passerines. In the first two seasons, intermittent sampling was the rule, but in autumn 2002 the study was continuous throughout the day and the season. Totally 1,832 individuals of 60 passerine species were ringed. Blackcap (Sylvia atricapilla) and Willow Warbler (Phylloscopus trochilus) were the two most common species. Blackcap dominates species composition in autumn seasons with a very high percentage (%33). Daily captures peaked in the early morning and with a smaller peak one hour before the sunset. Several waves of migrants were detected in autumn 2002, with most peaks in close correlation with those recorded at Cernek station, indicating some connection between migrant populations using both sites for stopover. Fat depositon rates showed at least Yalincak is a high quality stopover site for most migrant species since many species gained weight up to around 50% within a period of 10 days. This is the first study documenting passerine migration in Turkey, and it revealed that small wooded landscapes within less hospitable habitats provide crucial stopover habitat for many migrant passerines.

Bactrocera tryoni, the Queensland fruit fly, is established along the entire Australian east coast. It is a major pest of horticulture and arguably the worst horticultural insect pest in Australia. Adult flies lay eggs into fruit and resultant larvae feed on the flesh of the fruit. The population biology of B. tryoni has been well studied in temperate regions, where it has been established that climatic factors, particularly temperature and rainfall, limit population growth. In contrast, in subtropical and tropical regions, the population dynamics of the fly have been little studied. This thesis investigates the fly's phenology and abundance changes across subtropical and tropical Queensland and asks what factors govern the population cycles of B. tryoni in this state. Winter breeding and abundance of the fly, a component of the seasonal cycle which in south-east Queensland is fundamentally different from that observed in temperate Australia, is also investigated. A historical, extensive multi-year and multi-site trapping data set with from across Queensland was analysed to look at the effects of temperature, rainfall and relative humidity on B. tryoni trap catch. Trap data was further compared with the predicted phenology data generated by a DYMEX® based B. tryoni population phenology model. The phenology model used was based on a previously published model, but was also modified to more explicitly look at the effects of host plant availability and the presence or absence of non-reproductive over-wintering flies. Over-wintering field cage studies and a winter-spring field trapping study, both carried out in Brisbane, supplied additional data on B. tryoni's population abundance and capacity to breed during winter in the subtropics. Results show significant variation of monthly fly abundance for nine sites across Queensland. Abundance changed across sites in non-predictable ways. Annual population phenology within a site was, for some sites, highly consistent from year to year, but inconsistent for other sites. All sites in the subtropics showed some form of population depression during the cooler months, but breeding was continuous, albeit reduced at nearly all sites. Some tropical sites, where the climate is regarded as highly favourable for B. tryoni, still showed dramatic peaks and troughs in annual population abundance. There were relatively few significant correlations observed between weather factors and fly populations for any site. Output from the DYMEX population model suggested that fruit availability is a major driver of population dynamics in the tropical north of the state, while weather is more important in the subtropical south. The population dynamics of B. tryoni at sites along the central Queensland coast, where it is assumed that a mix of both weather and host fruit availability drive local populations, were poorly captured by the population model. Field cage results showed that B. tryoni successfully bred during winter in Brisbane, with pupal emergence starting in mid-winter (1st week of August), peaking in early spring (2nd week of September). Trap catch at orchards in Brisbane increased with increasing temperature and fruit availability, but diminished with decreasing temperature and fruit availability. The results suggest that B. tryoni has an optimal climate for population growth in the tropics, but fruit availability for offspring production limits population growth. In the subtropics however, both climate and fruit availability determine the population size. Winter temperatures are marginal for B. tryoni population growth in the subtropics.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.

The goal of this research was to construct a time series of accurate chlorophyll-a concentration for the Strait of Georgia (SoG), Canada, using an improved atmospheric correction scheme and workflow for the Moderate Resolution Imaging Spectroradiometer AQUA (MODIS) satellite instrument to describe the chla dynamics and spring bloom phenology in the SoG. In situ radiometric samples were acquired via Aerosol Robotic Network (AERONET), and hyperspectral data collected from a Hyperspectral Surface Acquisition System (HyperSAS) to assess three potential atmospheric correction schemes. Water property samples including total suspended material (TSM), chromophoric dissolved organic matter (CDOM), and chlorophyll concentrations (chla) were collected to further assess atmospheric corrections and the applied ‘Ocean Color 3 Modis’ (OC3M) standard chlorophyll algorithm. Regression, Absolute percentage difference (APD), Relative Percentage difference (RPD), and Root mean squared error (RMSE) analysis revealed the most appropriate method to be the ‘Management Unit of the North Seas Mathematical Models’ (MUMM) using the shortwave infrared spectrum (SWIR) to determine NIR-derived aerosol model. This method was used to construct a time series (July 2002-June 2014) of daily chlorophyll maps for all available imagery. Files were spatially binned into 8-day composites for the North and Central SoG where a modified threshold-based definition was used to determine the start of the spring phytoplankton bloom period, as well as timing of maxima and duration of the largest spring bloom. Results indicate Central SoG start dates range from late February to late April, with an average start date at the last week of March. These results compare favorably to Hindcast predictive modelling of bloom start dates. The Northern SoG bloom phenology starts on average 9 days earlier, and experiences lower chlorophyll-a magnitudes. Hierarchical clustering with correlation similarity of spring seasons indicate 2008 and 2007 were anomalous, while 2009 and 2012 were the most correlated for blooms occurring in the spring season. / Graduate / 0366 / 0416 / 0752 / 0368 / carswell@uvic.ca

Thesis (MScAgric)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Persimmon production is new to the Western Cape region of South Africa and is well suited to its Mediterranean climate. Export market opportunities for out-of-season fruit in traditional Northern Hemisphere markets have led to the planting of almost 700 ha of the astringent cultivar ‘Triumph’ since 1998. Production of other cultivars is negligible compared to ‘Triumph’. There is a need to study the vegetative and reproductive phenology of ‘Triumph’ in order to improve production under local conditions. In order to determine the physical characteristics of good bearing units, the effect of length and orientation of one-year-old shoots on bud break, vegetative growth, flowering, fruiting and fruit quality was evaluated. Further trials were conducted to determine the duration of the flowering period, flower distribution on one-year-old shoots and the timing of flower initiation. Shoots between 30-60 cm, the longest length studied, produced the most new vegetative growth, had the most flowers, and set the most fruit. Fruit also ripened faster on 30-60 cm shoots compared to shorter shoots. Shoots with more flowers were thicker than shoots of equal length, but with fewer flowers. Poor fruit set is one of the most important problems in persimmon cultivation. Experiments were conducted to determine the efficacy of gibberellic acid (GA3) and scoring or girdling during full bloom (FB) to increase fruit set and yield. Different GA3 concentrations (20 mg·L-1 and 40 mg·L-1) were evaluated. GA3 applications and scoring/girdling were applied at 30% FB or 30 and 70% FB. While GA3 treatments were ineffective, scoring increased fruit set and yields in young orchards (< 5-year-old) up to three times. In general, GA3 sprays decreased fruit size although it did not increase the number of fruit per tree. In more mature orchards (> 5 years old), scoring or girdling in combination with GA3 applications at 30 and 70% FB increased yield by an average of 16 tons (45%) compared to GA3 treatment on its own (35 tons). This increase in yield did not affect fruit size. Girdling and scoring were equally effective in increasing yield. When it comes to GA3 applications to improve fruit set in mature orchards, producers must bear in mind that 30% full bloom occurs already 2 to 4 days after the first flowers are open. Based on these data, guidelines to manage fruit set can be developed for the South African persimmon industry. However, these guidelines will also need to entail pruning and thinning strategies to prevent alternate bearing that may result from the high yields. ‘Triumph’ preferentially initiates flowers laterally in terminal quadrants of one-year-old shoots. This has to be taken into consideration with the development of pruning strategies. When timing thinning treatments, producers should keep in mind that flower initiation starts shortly after shoot elongation has ended and soon after fruit set. The short harvesting period of ‘Triumph’ puts pressure on producers and packing facilities, and shortens the marketing window of fruit. The final objective of this study was to advance or delay harvesting by using scoring or plant growth regulators. The effect of these treatments on fruit quality at harvest and after storage for 3 months at -0.5 °C and shelf life of 5 to 7 days at 15 °C were evaluated over two seasons. n-Propyl dihydrojasmonate (PDJ), aminoethoxyvinylglycine (AVG) and scoring generally did not affect fruit ripening and storability. 2-Cloroethyl phosphonic acid (ethephon) applied at 24 mg·L-1 4 weeks before the first of two harvest dates (WBFH) advanced ripening. Gibberellic acid (GA3) application at 50 mg·L-1 2 WBFH and 1-methylcyclopropene (MCP) applied immediately after harvest, delayed fruit ripening and reduced fruit softening during storage and shelf life. Future research should evaluate combined treatments of ethephon with MCP or GA3 to advance harvesting without negatively effecting storability of fruit. / AFRIKAANSE OPSOMMING: Verbouing van persimmon is ‘n nuut tot die Wes-Kaap streek van Suid-Afrika met sy geskikte Mediterreense klimaat. Uitvoergeleenthede vir buite-seisoen vrugte na tradisionele Noordelike Halfrond markte het sedert 1998 gelei tot die aanplant van bykans 700 ha van die vrank cultivar, ‘Triumph’. Ander cultivars word ook verbou, maar die hoeveelhede is weglaatbaar in vergelyking met ‘Triumph’. Daar bestaan ‘n behoefte om die vegetatiewe en reproduktiewe fenologie van ‘Triumph’ te bestudeer ten einde produksie onder plaaslike toestande te verbeter. Die effek van lengte en oriëntasie van een-jaar-oue lote op knopbreek, vegetatiewe groei, blomtyd, vrugset en vrugkwaliteit is geëvalueer ten einde die fisieke eienskappe van goeie dra-eenhede te bepaal. Verdere proewe is uitgevoer om die duur van die blomperiode, die verspreiding van blomme op een-jaar-oue lote en die periode van blominisiasie te bepaal. Lote tussen 30–60 cm, die langste lengte wat bestudeer is, produseer die meeste nuwe vegetatiewe groei, het die meeste blomme en set die meeste vrugte. Vrugte op 30–60 cm lange lote het ook vinniger ryp geword in vergelyking met vrugte op korter lote. Lote met baie blomme was dikker as lote van dieselfde lengte, maar met minder blomme. Swak vrugset is een van die belangrikste probleme wat persimmon produksie kniehalter. Eksperimente is uitgevoer om te bepaal of toediening van gibberelliensuur (GA3) en insnyding (scoring) of ringelering gedurende volblom (VB) effektief is om vrugset en produksie te verhoog. Verskillende GA3 konsentrasies (20 mg·L-1 en 40 mg·L-1) is geëvalueer. GA3 toegediening en insnyding/ringelering is uitgevoer by 30% VB of by 30% en 70% VB. Terwyl GA3 ondoeltreffend was in jong boorde (< 5-jaar-oud), het insnyding vrugset en produksie tot drie keer verhoog. GA3 het vruggrootte oor die algemeen verminder sonder dat daar ‘n toename in die aantal vrugte per boom was. In meer volwasse boorde (>5-jaar-oud) het insnyding/ringelering in kombinasie met GA3 toediening by 30 en 70% VB, produksie met gemiddeld 16 ton (45%) verhoog in vergelyking met net GA3-behandeling (35 ton). Hierdie verhoging in produksie het geen effek op vruggrootte gehad nie. Ringelering en insnyding was ewe effektief in die verhoging van produksie. Met die toediening van GA3 in volwasse boorde moet produsente in gedagte hou dat 30% VB bereik kan word binne 2 tot 4 dae nadat die eerste blomme oopgegaan het. Bogenoemde data stel ons in staat om riglyne vir die bestuur van vrugset te ontwikkel vir die Suid-Afrikaanse persimmon bedryf. Ten einde die ontstaan van alternerende drag as gevolg van hoë vrugladings te vermy, sal snoei- en uitdunstrategieë egter in ag geneem moet word met die saamstel van hierdie riglyne. ‘Triumph’ inisieer blomme hoofsaaklik lateraal in die terminale kwadrante van een-jaar-oue lote. Dit moet in aanmerking geneem word met die ontwikkeling van snoeistrategieë. Met die tydsberekening van uitdunbehandelings, moet produsente in gedagte hou dat blominisiasie in aanvang neem kort na lootgroeistaking en vrugset plaasgevind het. Die kort oesperiode van ‘Triumph’ plaas produsente en verpakkingsaanlegte onder druk, en verkort die bemarkingsvenster van vrugte. Die laaste doelwit van hierdie studie was om oes te vervroeg of uit te stel deur gebruik te maak van insnyding of plantgroeireguleerders. Die effek van hierdie behandelings op vrugkwaliteit met oes, na opberging vir 3 maande by -0.5 oC en raklewe van 5 tot 7 dae by 15 oC is geëvalueer oor twee seisoene. Npropieldihidrojasmonaat (PDJ), amino-etoksievinielglisien (AVG) en insnyding het oor die algemeen geen effek op die rypwording en opbergingsvermoë van vrugte gehad nie. Toediening van 2-chloro-etielfosfiensuur (ethephon) teen 24 mg·L-1, 4 weke voor die eerste van twee oeste het rypwording versnel. Toediening van gibberelliensuur (GA3) teen 50 mg·L-1 2 weke voor die eerste oes en 1-metielsiklopropeen (MCP) onmiddelik na oes, het rypwording vertraag en het die sagword van vrugte gedurende opberging en raklewe verminder. Ten einde oesdatums te vervroeg sonder om die opbergingsvermoë van vrugte te benadeel, behoort die kombinasie van ethephon met MCP of GA3 geëvalueer te word.