Models of phenology of the pine false webworm (PFW), Acantholyda erythrocephala and one of its parasitoids were developed from relationships between PFW spatial distribution and microweather. Development of subterranean stages of PFW was simulated from rate-summation models developed from nonlinear regression equations describing the relationship between temperature and rate of development of post-diapause prepupae and pupae. Defoliation caused by PFW increased the soil's exposure to solar radiation resulting in higher soil temperatures and a corresponding reduction in development time of subterranean stages. Predictability was enhanced slightly when the distribution of insects and temperature of the soil were incorporated into the model. Increasing the time increment used in the model from 1 to 4 h did not adversely affect its resolution. Mating and oviposition of PFW occur within a few hours of emerging from the soil and the majority of PFW eggs were mature and ready for deposition at female emergence. Potential fecundity of PFW was accurately predicted from adult wet and dry weights. The oviposition pattern of PFW was also described by a model based on temperature-dependent oviposition and ageing rate functions. The effect of larval web construction on the development of arboreal stages was investigated. When exposed to sunlight, the web traps heat and raises the body temperature of its inhabitants. A model was developed and used to examine the significance of the web microclimate for development of larvae. Relationships between web temperatures, canopy temperatures and standard meteorological methods were developed to permit using data from standard weather stations to drive the model. Larval development increased by 1.4 to 2.8 d when estimated web temperatures were incorporated into the model, while development was retarded by 2.6 to 4.0 d when canopy temperatures were used instead of meteorological screen temperatures. Two ichneumonid parasitoids, Sinophorus megalodontis and an undescribed species of Olesicampe were reared from eonymphs of PFW. Morphological methods for distinguishing the immature stages of the parasitoids were developed. A predictive model for subterranean development and adult longevity of Olesicampe sp. was used to describe and to compare phenological observations from emergence traps, Malaise traps and dissections of host larvae. The effectiveness of the parasitoids as natural control agents is discussed in relation to host synchrony, encapsulation, and multi- and superparasitism. / Land and Food Systems, Faculty of / Graduate

Orientador: Lilian Beatriz Penteado Zaidan / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T09:17:44Z (GMT). No. of bitstreams: 1 Rondon_JosimaraNolasco_D.pdf: 1536546 bytes, checksum: 297d7328b9b2a132fca75bfad73844c8 (MD5) Previous issue date: 2006 / Resumo: Uma população de Bauhinia holophylla Steud. localizada no cerrado sensu stricto da Reserva Biológica e Estação Experimental de Moji Guaçu (RBEE de Moji Guaçu) foi estudada quanto a sua fenologia reprodutiva, expectativa de vida foliar, predação de sementes, germinação, fotoperíodo e regeneração natural. O padrão de distribuição da população adulta e jovem de B. holophylla, na área estudada é do tipo agregado. A população jovem e adulta de B. holophylla na RBEE de Moji Guaçu pode ser considerada juvenil, concentrando a maioria dos indivíduos nas primeiras classes de crescimento em altura e diâmetro. A expectativa média de vida da folha no primeiro ano de estudo foi de 8,2 meses, enquanto no segundo ano foi de 7,6 meses. A produtividade primária da fração folhas de 21 plantas de B. holophylla amostradas foi mais intensa nos meses de julho a agosto, durante o período de estudo (dois anos), portanto, durante a estação seca. A fração flores e botões esteve associada ao período da estação chuvosa, com produção maior nos meses de novembro a janeiro. A mortalidade foliar coincidiu com o período de menor precipitação na estação seca. A queda total das coortes foliares ocorreu ao mesmo tempo, na estação seca, estando a presença da folha durante a estação chuvosa, relacionada à produção de fotoassimilados para a planta, que serão usados na reprodução e/ou armazenados como amido no xilopódio. Plantas de B. holophylla apresentaram maior altura e diâmetro caulinar, e maior número de folhas nos tratamentos fotoperiódicos de 16 e 20 horas que nos tratamentos de 8 e 12 horas. A predação de sementes é uma das principais causas da inexistência de plântulas no cerrado. Contudo, a regeneração natural não está comprometida devido à presença do xilopódio. As sementes de B. holophylla são neutras à luz para a germinação e germinam em uma faixa ampla de temperatura. A permanência efêmera de sementes de B. holophylla no banco de sementes do solo de cerrado deve-se muito provavelmente à neutralidade à luz e velocidade de germinação alta em temperaturas na faixa de 25ºC a 30ºC. Práticas de manejo na RBEE de Moji Guaçu a partir do controle de larvas e de insetos predadores são fundamentais para aumentar a produção de sementes sadias de B. holophylla. Investigações sobre auto-ecologia, serapilheira, fenologia reprodutiva e dinâmica populacional devem ser propostas para espécies do Cerrado. Essas investigações podem auxiliar nos programas de recuperação de áreas remanescentes de cerrado e constituem modelos para estudos de populações de espécies vegetais do cerrado / Abstract: A population of Bauhinia holophylla located at a cerrado area in the Reserva Biológica e Estação Experimental de Moji Guaçu was studied in relation to reproductive phenology, leaf life span, seed predation, seed germination and aspects of plant regeneration. The distribution pattern of the juvenile and adult population is considered agregated. This population can be considered on the juvenile stage, due to, the greater number of plants concentrate in to the first size classes (height and diameter). The mean leaf life span was 8.2 months in the first year and 7.6 months in the second year. The primary productivity of leaves was more intense, during dry season (July-August). Leaf mortality with the period of the minor precipitation registered (dry season). Flower and bud production was associated to the wet season. Leaf fall ocurred during dry season. The new leaves could garantee the production of photoassimilates that would be utilized by all plant organs in their metabolic activities and as a reserve carbohydrate stored in the xylopodium as starch. Higher stems and stem diameter and leaf number in plants were observed in the photoper iodic treatments of 16h and 20 hours (long days) than in plants maintened in 8h and 12 hours (short days). Seeds predation is the principal cause of inexistence of seedlings in that the cerrado area. However, plant regeneration is provided by xylopodium. The seed is neutral to light for germination at the temperature range of 20ºC to 35ºC. Germination speed germination at 25ºC in the dark was higher than under light. The ephemeral permanence of the seeds of B. holophylla in the cerrado soil seed bank, is probably due to neutrality of light and their fast germination at 25ºC-30ºC. Thus, management polices at the Reserva Biológica e Estação Experimental de Moji Guaçu to decrease larvae and predator insects are fundamental to enlarge the production of healthy seeds of B. holophylla. Investigation on auto-ecology, litter and reproductive phenology, may give important information about of species occurring in the Cerrado. Investigations can support recuperation programmes of remnant cerrado areas and constitute model to study populations of plants species the Cerrado / Doutorado / Biologia Vegetal / Doutor em Biologia Vegetal

A perda de área foliar, em sua maior parte resultante da ação de herbívoros, é um dos fatores que regulam o sucesso reprodutivo de uma planta e indiretamente de todos os consumidores relacionados na comunidade. A maior parte dos estudos feitos com perda foliar e herbivoria são pontuais, ou seja, referem-se a uma ou poucas espécies vegetais. Para os cerrados, a savana tropical brasileira, a maior savana em extensão e diversidade no mundo, não há nenhum estudo que investigue a dinâmica de perda de área foliar ao longo do tempo na comunidade, considerando os fatores climáticos e fenológicos que podem influenciar este processo, além da presença dos principais predadores de herbívoros atrópodes na vegetação de cerrado, as formigas, sendo este o principal objetivo do presente estudo. O estudo foi desenvolvido em uma área de reserva de Cerrado de 628 ha, situada em Uberlândia, MG (18º59S, 48º18O), tendo os dados sido coletados de janeiro a dezembro de 2007 (bimestralmente) e de 2008 (mensalmente). Foram estabelecidos aleatoriamente na área de cerrado sensu stricto da reserva, 15 quadrantes de 10m x 10m onde todos os indivíduos com diâmetro à altura do peito igual ou superior a três centímetros foram marcados e incluídos na amostra. Em cada quadrante observou-se (sem remoção), seis folhas (escolhidas aleatoriamente duas da parte alta, duas da parte mediana e duas de ramos mais baixos), por planta de cada espécie, sendo registrada a porcentagem de área foliar perdida. Foram amostrados um total de 1006 indivíduos distribuídos em 82 espécies e 34 famílias. A espécie Ouratea spectabilis (137 indivíduos) foi a mais abundante na área de estudo, seguida de Banisteriopsis malifolia (122), Machaerium acutifolium (59) e Tabebuia ochracea (41). A perda de área foliar variou significativamente ao longo do tempo (meses) e entre as famílias e espécies de plantas. Os meses mais secos do ano apresentaram a maior perda de área foliar tanto em 2007 (abril, junho e agosto) quanto em 2008 (de maio a agosto). Os fatores climáticos influenciaram significativamente a perda de área foliar, pois ela variou ao longo do tempo. Portanto, os resultados do presente estudo indicaram que a perda de área foliar da comunidade de plantas de cerrado varia sazonalmente e ocorre com maior intensidade na estação seca. Fatores abióticos como temperatura e precipitação influenciam a fenologia das espécies de plantas, que buscam o melhor momento para maximizar seu desenvolvimento e evitar que inimigos naturais causem perdas significativas para sua sobrevivência e sucesso reprodutivo. As características de cada espécie promovem diferenças na perda de área foliar, devido às defesas e/ou associações mutualísticas que possuem. A presença de nectários extraflorais associados às formigas desempenha um papel significativo para as plantas. Dentre os fatores bióticos, a presença de ninhos de formigas Ectatomma teve um impacto positivo para as plantas reduzindo a perda de área foliar. / The loss of leaf area, mostly resulting from the action of herbivores is one of the factors that regulate the reproductive success of a plant and indirectly to all consumers connected to the community. Most studies of herbivory and leaf loss are punctual, i.e., refer to one or a few plant species. In the cerrado, a tropical savanna in Brazil, the largest savanna in scope and diversity in the world, there are no studies to investigate the dynamics of loss of leaf area over time in the community, considering the climatic factors, phenology and carnivorous ants that can influence this process, which is the main objective of this study. The study was conducted in a closed area of 628 ha of Cerrado, located in Uberlandia, Brazil (18 º 59\'S, 48 18\'W) and the data were collected from January to December 2007 (bimonthly) and 2008 (monthly). Were established randomly in the area of cerrado of the reserve, 15 quarters of 10m x 10m where all trees with diameter at breast height greater than or equal to three centimeters were marked with numbered label and sampled. In each quadrant was observed (without removal), six leaves (randomly chosen two of high part, two of the middle, and two of the lower branches), in plant species, and recorded the percentage of leaf area lost. We sampled a total of 1006 individuals belonging to 82 species and 34 families. The species Ouratea spectabilis (137 individuals) was the most abundant in the study area, followed by Banisteriopsis malifolia (122), Machaerium acutifolium (59) and Tabebuia ochracea (41). The loss of leaf area varied significantly over time (months) and between families and species of plants. The driest months of the year showed the greatest loss of leaf area in both 2007 (April, June and August) and in 2008 (May-August). Climatic factors also significantly influenced the loss of leaf area, as it varied over time, depending on the rainfall and temperature variation. Therefore, the results of this study indicated that the loss of leaf area community of cerrado plants varies seasonally and occurs mostly in the dry season. Abiotic factors like temperature and rainfall influence the phenology of species of plants, seeking the best time to maximize their development and prevent natural enemies result in significant losses for their survival and reproductive success. The characteristics of each species promote differences in leaf area loss due to defenses and / or mutualistic associations they have. The presence of extrafloral nectaries associated with ants play a significant role for plants. For this reason, among the biotic factors, the presence of Ectatomma nests had a significant positive impact on reducing the loss of leaf area, since these ants are predators of herbivores.

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第22802号 / 情博第732号 / 新制||情||125(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 守屋 和幸, 教授 大手 信人, 教授 河原 達也 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DGAM

No description available.

The Red Sea is an arid environment, without riverine inputs, oligotrophic waters and extreme temperature and salinity. Avicennia marina is the dominant vegetation in the shores of the Red Sea. However, little is known about their distribution, dynamics, and services. Therefore, the aim of this Ph.D. was to obtain the basic information needed to evaluate their role in the coastal ecosystems and quantify their services. With that objective we 1) estimated the past and present distribution of mangroves in the Red Sea, 2) investigated the growth, leave production and floration 3) examined the growth limiting factors 4) measured the nutrients and heavy metal dynamics in the leaves and 5) estimated carbon sequestration. We found an increase of about 12% in the last 41 years, which contrasts with global trends of decrease. The extreme conditions in the Red Sea contributed to limit their growth resulting in stunted trees. Hence, we surveyed Central Red Sea mangroves to estimate their node production with an average of 9.59 node y-1 then converted that number into time to have a plastochrone interval of 38 days. As mangroves are taller in the southern Red Sea where both temperature and nutrients are higher than the Central Red Sea, we assessed nutrient status Avicennia marina propagules and naturally growing leaves to find the leaves low in nutrient concentrations (N < 1.5 %, P < 0.09 %, Fe < 0.06) and that nutrients are reabsorbed before shedding the leaves (69%, 72% and 35% for N, P, and Fe respectively). As a result, we conducted a fertilization experiment (N, P, Fe and combinations) to find that iron additions alone led to significant growth responses. Moreover, we estimated their leaf production and used our previous estimates of both the total cover mangrove in the Red Sea along with plastochrone interval to assess their total nutrients flux per year to be 2414 t N, 139 t P and 98 t Fe. We found them to sequester 34 g m-2 y-1, which imply 4590 tons of carbon sequestered per year for the total mangroves covered by the Red Sea.

Ecological indicators are defined as quantifiable metrics that can be used to monitor the state of ecosystems and their response to environmental perturbations. In the global oceans, commonly used indicators are typically based on the presence and distribution of phytoplankton (as indexed by the concentration of chlorophyll-a [Chl-a]), which form the base of oceanic food webs. Phytoplankton phenology (the timing of phytoplankton growth) and phytoplankton size structure are particularly important ecological indicators that can be derived via ocean colour remote sensing. Phytoplankton phenology has a direct control on food availability, which subsequently impacts the survival of higher trophic levels and the structure of marine ecosystems. Meanwhile, phytoplankton size structure can be used to define the major functional groups that ultimately influence marine food web structure, biogeochemical cycling and carbon export. The Red Sea is a relatively unexplored tropical marine ecosystem, particularly in relation to its large-scale biological dynamics. In light of recent evidence of rapid regional warming, the need to monitor the response of the Red Sea to potential future ecosystem modifications is becoming more imminent. Using a combination of contemporary oceanographic tools, with an emphasis on ocean colour remote sensing, this PhD thesis attempts to validate the retrieval of phytoplankton ecological indicators in the Red Sea - specifically phytoplankton abundance, phenology and size structure. The interannual variability of both indicators and their linkages with the regional physical environment are also explored.

Species are experiencing shifts in their phenology (i.e., seasonal timing of recurring biological events) due to climate change, leading to disruptions in the relative timing of interacting species. These shifts can be detrimental to the fitness of the consumer (e.g., herbivore) in the interaction. In its larval form, the monarch butterfly (Danaus plexippus) is a specialist herbivore that feeds on milkweed plants (Asclepias spp.). Given that plants generally experience seasonal declines in quality, it is hypothesized that if climate change disrupts the timing of the larval stage relative to the availability of younger milkweed plants, monarch performance will be negatively affected. In this thesis, I explore the potential for negative consequences for the eastern monarch population due to potential shifts in the timing of their interaction with milkweed—due to phenological shifts in either species. I used field surveys around Ottawa, ON to determine monarch oviposition preference on common milkweed (Asclepias syriaca) plants and the seasonal availability of their preferred plants. To determine the potential consequences for monarch fitness where females oviposit on non-preferred plants, I conducted a field experiment to assess the effect of milkweed size on monarch larval performance. Based on field surveys, females preferentially oviposited on smaller milkweed plants in earlier developmental stages with low levels of discolouration. Plants in early developmental stages were consistently available in large proportion over the summer season. These results suggest that even if the relative timing of the monarch-milkweed interaction in the eastern population is shifted due to climate change, there will likely be suitable milkweed plants available for oviposition throughout the breeding season, which could act as a buffer to disruptions in the relative timing of the interaction. I found that bigger plants exuded more latex and had thicker leaves than smaller plants. However, larval performance was unaffected by these plant quality differences. While it is unclear how the relative timing of the monarch-milkweed interaction will change in the future, my results suggest that shifts in the relative timing of their interaction within the breeding season are unlikely to have negative consequences for larval performance in eastern Ontario. Future studies should determine how the relative timing of the interaction will change in the region and explore how climate change will affect the quality of milkweed plants.

Global warming is causing a general trend of rising temperatures worldwide. Simultaneously there is also a decline in populations of pollinators all over the world. Therefore, it is important to examine the effect warming temperatures might have on different pollinator species. The focus of this study was to look at how flight phenology of hoverflies in southern Sweden is affected by rising summer temperatures using two regions differing in temperature, and 11 years of citizen science data on hoverfly observations. Summer temperature and observations of 13 species were used. Although four species had a significantly earlier first flight in years with warmer weather, there were overall no apparent trends toward earlier or longer flight periods due to temperature deviation. However, geographical location had a strong impact on flight behaviour of hoverflies in Sweden with hoverflies in Götaland having an earlier first flight compared to Svealand (located further north). This might be the result of an earlier onset of spring and summer in Götaland than in Svealand. The results of this study indicate that more factors than temperature affect flight phenology in hoverflies.

An inclined point frame was used to measure leaf area indicies in an alpine tundra Kobresia stand and Deschampsia meadow on Niwot Ridge, Colorado. Measurements were made throughout the summer of 1971 at vi various heights in the canopy and for each species in the two communities. Maximum leaf area indices of 2.2 and 2.0 occurred in the Kobresia and Deschampsia sites, respectively. The Kobresia site was characterized by a single dominant species, Kobresia myosuroides, and a predominance of vegetation within 2.5 cm of mean ground level. The Deschampsia site had no single dominant species. The region of maximum foliage shifted from the 2.5 to 5 cm height zone in June to the 5 to 10 cm zone in early August. Phenological observations revealed a greater number of vegetative contacts in the Deschampsia site on all sampling dates. Certain shared species varied in their phenological patterns. It is suggested that differences in the duration of snow cover and surface melt-water may be related to the variation in phenological patterns in the two sites. In both communities, maximum LAI occurred when flower and fruit production overlapped. Arctic tundra LAI values, measured using similar methods, were less than half the maximum LAI values reached in the alpine communities examined here.