Search results for "PHENOLOGY"
showing 10 items of 146 documents
Large-scale migration synchrony between parasitoids and their host
2015
1. Parasitoids are a valuable group for conservation biological control. In their role as regulators of aphid pests, it is critical that their lifecycle is synchronised with their hosts in both space and time. This is because a synchronised parasitoid community is more likely to strengthen the overall conservation biological control effect, thus damping aphid numbers and preventing potential outbreaks. One component of this host–parasitoid system was examined, that of migration, and the hypothesis that peak summer parasitoid and host migrations are synchronised in time was tested. 2. Sitobion avenae Fabricius and six associated parasitoids were sampled from 1976 to 2013 using 12.2-m suction…
Trends in phenological parameters and relationship between land surface phenology and climate data in the Hyrcanian forests of Iran
2017
Vegetation activity may be changed in response to climate variability by affecting seasonality and phenological events. Monitoring of land surface phenological changes play a key role in understanding feedback of ecosystem dynamics. This study focuses on the analysis of trends in land surface phenology derived parameters using normalized difference vegetation index time series based on Global Inventory Monitoring and Mapping Studies data in the Hyrcanian forests of Iran covering the period 1981–2012. First, we applied interpolation for data reconstruction in order to remove outliers and cloud contamination in time series. Phenological parameters were retrieved by using the midpoint approach…
When Climate Turns Nasty, What Are Recent and Future Implications? Ecological and Human Health Review of Climate Change Impacts
2020
Purpose of Review: The impacts of climate change on biodiversity in the last three decades have increasingly assumed from significant to threatening proportions and this causes major global concerns. This study aims at examining the recent and future impacts of global climate change on both ecological resources and human well-being. This review study is based on the general concept of ecological resilience: that coping with climate change stresses and disturbances depends on social resilience, political and environmental strategies accessible in a community. The study assessed over 300 peer-reviewed publications, both articles and books, which linked climate change impacts on ecosystems to …
Influence of climate change on phenological phases in Latvia and Lithuania
2009
To investigate the impact of recent climatic changes on plant development, this study used phenological data of the volunteer networks in Latvia and Lithuania from the 1971-2000 period. The phenological calendar method was applied. Phenological seasons were described using data on 6 phenological phases at 10 stations. The growing season was described using birch Betula pendula as an example. Correlation analysis, linear regression and non-parametric Mann-Kendall trend tests were applied to establish the relationship between phenological phases and meteorological factors (temperature, precipitation) and the North Atlantic Oscillation (NAO). The results indicate a statisti- cally significant …
Surviving in a warmer world: environmental and genetic responses
2012
There are numerous reports in the literature of advancing trends in phenophases of plants, insects and birds attributed to rising temperature resulting from human-driven climate warming. One mechanism that enables a population to respond rapidly to changes in the environ- ment is termed phenotypic plasticity. This plasticity grants a degree of flexibility to enable the tim- ing of developmental stages to coincide with resource availability. If, however, environmental con- ditions exceed the plastic limits of an organism, evolutionary change may be necessary in order to ensure continued survival of their populations. We review evidence for phenotypic plasticity and genetic adaptation in phen…
Limitation of Reproductive Success by Food Availability and Breeding Time in Pied Flycatchers
1998
Seasonal variation in reproductive success is a common phenomenon in many taxa. In birds, the costs and benefits associated with alternative breeding dates cause variation in clutch size, which is a main cause of seasonal decline in reproductive success. An immediate cause for this might be seasonal variation in the environment, or alternatively, but not mutually exclusively, date-independent differences in the parental/territory quality of early and late parents. The predictions of these hypotheses on seasonal reduction of reproductive success were tested by manipulating the hatching date and the amount of food during the nestling period of Pied Flycatchers (Ficedula hypoleuca). Delay in t…
Multiple aspects of plasticity in clutch size vary among populations of a globally-distributed songbird.
2013
Plasticity in life-history characteristics can influence many ecological and evolutionary phenomena, including how invading organisms cope with novel conditions in new locations or how environmental change affects organisms in native locations. Variation in reaction norm attributes is a critical element to understanding plasticity in life history, yet we know relatively little about the ways in which reaction norms vary within and among populations. We amassed data on clutch size from marked females in eight populations of house sparrows (Passer domesticus) from North America and Europe. We exploited repeated measures of clutch size to assess both the extent of within-individual phenotypic …
Contrasting temperature responses in seasonal timing of cercariae shedding by Rhipidocotyle trematodes
2022
AbstractGlobal warming is likely to lengthen the seasonal duration of larval release by parasites. We exposed freshwater mussel hosts, Anodonta anatina, from 2 high-latitude populations to high, intermediate and low temperatures throughout the annual cercarial shedding period of the sympatric trematodes Rhipidocotyle fennica and R. campanula, sharing the same transmission pathway. At the individual host level, under warmer conditions, the timing of the cercarial release in both parasite species shifted towards seasonally earlier period while its duration did not change. At the host population level, evidence for the lengthening of larvae shedding period with warming was found for R. fennica…
The genetic regulation of avian migration timing: combining candidate genes and quantitative genetic approaches in a long-distance migrant
2021
Abstract Plant and animal populations can adapt to prolonged environmental changes if they have sufficient genetic variation in important phenological traits. The genetic regulation of annual cycles can be studied either via candidate genes or through the decomposition of phenotypic variance by quantitative genetics. Here, we combined both approaches to study the timing of migration in a long-distance migrant, the collared flycatcher (Ficedula albicollis). We found that none of the four studied candidate genes (CLOCK, NPAS2, ADCYAP1 and CREB1) had any consistent effect on the timing of six annual cycle stages of geolocator-tracked individuals. This negative result was confirmed by direct ob…
Remote sensing of vegetation dynamics in agro-ecosystems using smap vegetation optical depth and optical vegetation indices
2017
The ESA's SMOS and the NASA's SMAP missions, launched in 2009 and 2015, respectively, are the first two missions having on-board L-band microwave sensors, which are very sensitive to the water content in soils and vegetation. Focusing on the vegetation signal at L-band, we have implemented an inversion approach for SMAP that allows deriving vegetation optical depth (VOD, a microwave parameter related to biomass and plant water content) alongside soil moisture, without reliance on ancillary optical information on vegetation. This work aims at using this new observational data to monitor the phenology of crops in major global agro-ecosystems and enhance present agricultural monitoring and pre…