نتایج جستجو برای: phenological
تعداد نتایج: 3985 فیلتر نتایج به سال:
Climate change may disrupt interspecies phenological synchrony, with adverse consequences to ecosystem functioning. We present here a 40-y-long time series on 10,425 dates that were systematically collected in a single Russian locality for 97 plant, 78 bird, 10 herptile, 19 insect, and 9 fungal phenological events, as well as for 77 climatic events related to temperature, precipitation, snow, i...
Changes in vegetation phenology are recognized as being possibly the most important early indicator of the impact of climate change on ecosystems. Time series of image data are accepted as being the best way to map these changes, if we can derive suitable indices from the huge volumes of time series data that make the interpretation of these time series difficult. The problem is thus to derive ...
The timing of the fruit-set stage (i.e., start and end of fruit set) is crucial in a plant's life cycle, but its response to temperature change is still unclear. We investigated the timing of seven phenological events, including fruit-set dates during 3 yr for six alpine plants transplanted to warmer (approximately +3.5°C in soils) and cooler (approximately -3.5°C in soils) locations along an a...
In the past few years there has been a resurgence of interest in the possibility of detecting climate change using natural systems (see, for example, Crick and Sparks 1999; Sparks and Menzel 2002; Hughes 2003; Parmesan and Yohe 2003; Root et al. 2003). The study of recurring natural (or biological) events, often in relation to climate, is known as phenology. These studies typically record event...
Phenology is an indicator of the impact of climate on vegetation. As the representation of human activities, urbanization affects vegetation phenology by changing the local climate such as temperature, humidity, wind speed, etc. Recent studies starts to focus on the impacts of urbanization intensity on phenology. In order to understand the relationship between urbanization intensity and phenolo...
Phenological changes within a growth season were investigated in two grazed, seminatural grasslands in southern Sweden. On four occasions during the growth season, two independent observers recorded plant frequency and percentage cover. The vegetation data sets were analysed with ordination methods. The temporal changes were highly significant, but accounted for only a small part of the total v...
In the context of defining a procedure for near real time land use/land cover (LULC) mapping with seasonal updated products, this research examines the use of time-series and phenological indicators from MODIS NDVI. 16-day NDVI composites from MODIS (MOD13Q1) covering the period from 2001 to the present were acquired for three test sites located in different parts of Europe. The newly proposed ...
We present an online database that provides unrestricted and free access to over 16 million plant phenological observations from over 8,000 stations in Central Europe between the years 1880 and 2009. Unique features are (1) a flexible and unrestricted access to a full-fledged database, allowing for a wide range of individual queries and data retrieval, (2) historical data for Germany before 195...
Understanding and interpreting the temporal variations of the vegetation growth can provide valuable information on its dynamics and in case of crops provide an estimate of the phenological milestones that can help describe the crop. The focus of this work is to use the phenological parameters derived from MODIS EVI time series composite data to map the variability in cropping practices. These ...
A plausible case of allochronic differentiation, where barrier to gene flow is primarily attributable to a phenological shift, was recently discovered in Portugal for the pine processionary moth Thaumetopoea pityocampa. Previous results suggested that the observed 'summer population' (SP) originated from the sympatric winter population (WP). Our objectives were to finely analyse these patterns ...
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