Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors (such as elevation).
Examples include the date of emergence of leaves and flowers, the first flight of butterflies, the first appearance of migratory birds, the date of leaf colouring and fall in deciduous trees, the dates of egg-laying of birds and amphibia, or the timing of the developmental cycles of temperate-zone honey bee colonies. In the scientific literature on ecology, the term is used more generally to indicate the time frame for any seasonal biological phenomena, including the dates of last appearance (e.g., the seasonal phenology of a species may be from April through September).
Because many such phenomena are very sensitive to small variations in climate, especially to temperature, phenological records can be a useful proxy for temperature in historical climatology, especially in the study of climate change and global warming. For example, viticultural records of grape harvests in Europe have been used to reconstruct a record of summer growing season temperatures going back more than 500 years.In addition to providing a longer historical baseline than instrumental measurements, phenological observations provide high temporal resolution of ongoing changes related to global warming.
The word is derived from the Greek φαίνω (phainō), "to show, to bring to light, make to appear"+ λόγος ( logos ), amongst others "study, discourse, reasoning" and indicates that phenology has been principally concerned with the dates of first occurrence of biological events in their annual cycle.
The term was first used by Charles François Antoine Morren, a professor of Botany at the University of Liège (Belgium).Morren was a student of Adolphe Quetelet. Quetelet made plant phenological observations at the Royal Observatory of Belgium in Brussels. He is considered "one of 19th century trendsetters in these matters." In 1839 he started his first observations and created a network over Belgium and Europe that reached a total of about 80 stations in the period 1840-1870.
Morren participated in 1842 and 1843 in Quetelets 'Observations of Periodical Phenomena' (Observations des Phénomènes périodiques),and at first suggested to mention the observations concerning botanical phenomena 'anthochronological observations'. That term had already been used in 1840 by Carl Joseph Kreutzer.
But 16 December 1849 Morren used the term 'phenology' for the first time in a public lecture at the Royal Academy of Science, Letters and Fine Arts of Belgium in Brussels,to describe “the specific science which has the goal to know the ‘’manifestation of life ruled by the time’’.”
It would take four more years before Morren first published “phenological memories”.That the term was not really common in the decades to follow may be shown by an article in The Zoologist of 1899. The article describes an ornithological meeting in Sarajevo, where 'questions of Phaenology' were discussed. A footnote by the Editor, William Lucas Distant, says: “This word is seldom used, and we have been informed by a very high authority that it may be defined as "Observational Biology," and as applied to birds, as it is here, may be taken to mean the study or science of observations on the appearance of birds.”
Observations of phenological events have provided indications of the progress of the natural calendar since ancient agricultural times. Many cultures have traditional phenological proverbs and sayings which indicate a time for action: "When the sloe tree is white as a sheet, sow your barley whether it be dry or wet" or attempt to forecast future climate: "If oak's before ash, you're in for a splash. If ash before oak, you're in for a soak". But the indications can be pretty unreliable, as an alternative version of the rhyme shows: "If the oak is out before the ash, 'Twill be a summer of wet and splash; If the ash is out before the oak, 'Twill be a summer of fire and smoke." Theoretically, though, these are not mutually exclusive, as one forecasts immediate conditions and one forecasts future conditions.
The North American Bird Phenology Program at USGS Patuxent Wildlife Research Center (PWRC) is in possession of a collection of millions of bird arrival and departure date records for over 870 species across North America, dating between 1880 and 1970. This program, originally started by Wells W. Cooke, involved over 3,000 observers including many notable naturalists of the time. The program ran for 90 years and came to a close in 1970 when other programs starting up at PWRC took precedence. The program was again started in 2009 to digitize the collection of records and now with the help of citizens worldwide, each record is being transcribed into a database which will be publicly accessible for use.
The English naturalists Gilbert White and William Markwick reported the seasonal events of more than 400 plant and animal species, Gilbert White in Selborne, Hampshire and William Markwick in Battle, Sussex over a 25-year period between 1768 and 1793. The data, reported in White's Natural History and Antiquities of Selborneare reported as the earliest and latest dates for each event over 25 years; so annual changes cannot therefore be determined.
In Japan and China the time of blossoming of cherry and peach trees is associated with ancient festivals and some of these dates can be traced back to the eighth century. Such historical records may, in principle, be capable of providing estimates of climate at dates before instrumental records became available. For example, records of the harvest dates of the pinot noir grape in Burgundy have been used in an attempt to reconstruct spring–summer temperatures from 1370 to 2003;the reconstructed values during 1787–2000 have a correlation with Paris instrumental data of about 0.75.
Robert Marsham, the founding father of modern phenological recording, was a wealthy landowner who kept systematic records of "Indications of spring" on his estate at Stratton Strawless, Norfolk, from 1736. These took the form of dates of the first occurrence of events such as flowering, bud burst, emergence or flight of an insect. Generations of Marsham's family maintained consistent records of the same events or "phenophases" over unprecedentedly long periods of time, eventually ending with the death of Mary Marsham in 1958, so that trends can be observed and related to long-term climate records. The data show significant variation in dates which broadly correspond with warm and cold years. Between 1850 and 1950 a long-term trend of gradual climate warming is observable, and during this same period the Marsham record of oak-leafing dates tended to become earlier.
After 1960 the rate of warming accelerated, and this is mirrored by increasing earliness of oak leafing, recorded in the data collected by Jean Combes in Surrey. Over the past 250 years, the first leafing date of oak appears to have advanced by about 8 days, corresponding to overall warming on the order of 1.5 °C in the same period.
Towards the end of the 19th century the recording of the appearance and development of plants and animals became a national pastime, and between 1891 and 1948 the Royal Meteorological Society (RMS) organised a programme of phenological recording across the British Isles. Up to 600 observers submitted returns in some years, with numbers averaging a few hundred. During this period 11 main plant phenophases were consistently recorded over the 58 years from 1891–1948, and a further 14 phenophases were recorded for the 20 years between 1929 and 1948. The returns were summarised each year in the Quarterly Journal of the RMS as The Phenological Reports . Jeffree (1960) summarised the 58 years of data,which show that flowering dates could be as many as 21 days early and as many as 34 days late, with extreme earliness greatest in summer-flowering species, and extreme lateness in spring-flowering species. In all 25 species, the timings of all phenological events are significantly related to temperature, indicating that phenological events are likely to get earlier as climate warms.
The Phenological Reports ended suddenly in 1948 after 58 years, and Britain remained without a national recording scheme for almost 50 years, just at a time when climate change was becoming evident. During this period, individual dedicated observers made important contributions. The naturalist and author Richard Fitter recorded the First Flowering Date (FFD) of 557 species of British flowering plants in Oxfordshire between about 1954 and 1990. Writing in Science in 2002, Richard Fitter and his son Alistair Fitter found that "the average FFD of 385 British plant species has advanced by 4.5 days during the past decade compared with the previous four decades."They note that FFD is sensitive to temperature, as is generally agreed, that "150 to 200 species may be flowering on average 15 days earlier in Britain now than in the very recent past" and that these earlier FFDs will have "profound ecosystem and evolutionary consequences". In Scotland, David Grisenthwaite meticulously recorded the dates he mowed his lawn since 1984. His first cut of the year was 13 days earlier in 2004 than in 1984, and his last cut was 17 days later, providing evidence for an earlier onset of spring and a warmer climate in general.
National recording was resumed by Tim Sparks in 1998and, from 2000, has been led by citizen science project Nature's Calendar , run by the Woodland Trust and the Centre for Ecology and Hydrology. Latest research shows that oak bud burst has advanced more than 11 days since the 19th century and that resident and migrant birds are unable to keep up with this change.
In Europe, phenological networks are operated in several countries, e.g. Germany's national meteorological service operates a very dense network with approx. 1200 observers, the majority of them on a voluntary basis.The Pan European Phenology (PEP) project is a database that collects phenological data from European countries. Currently 32 European meteorological services and project partners from across Europe have joined and supplied data.
There is a USA National Phenology Network in which both professional scientists and lay recorders participate.
Many other countries such as Canada (Alberta Plantwatch and Saskatchewan PlantWatch), China and Australia also have phenological programs.
In eastern North America, almanacs are traditionally used[ by whom? ] for information on action phenology (in agriculture), taking into account the astronomical positions at the time. William Felker has studied phenology in Ohio, US, since 1973 and now publishes "Poor Will's Almanack", a phenological almanac for farmers (not to be confused with a late 18th-century almanac by the same name).
In the Amazon rainforests of South America, the timing of leaf production and abscission has been linked to rhythms in gross primary production at several sites.Early in their lifespan, leaves reach a peak in their capacity for photosynthesis, and in tropical evergreen forests of some regions of the Amazon basin (particularly regions with long dry seasons), many trees produce more young leaves in the dry season, seasonally increasing the photosynthetic capacity of the forest.
Recent technological advances in studying the earth from space have resulted in a new field of phenological research that is concerned with observing the phenology of whole ecosystems and stands of vegetation on a global scale using proxy approaches. These methods complement the traditional phenological methods which recorded the first occurrences of individual species and phenophases.
The most successful of these approaches is based on tracking the temporal change of a Vegetation Index (like Normalized Difference Vegetation Index(NDVI)). NDVI makes use of the vegetation's typical low reflection in the red (red energy is mostly absorbed by growing plants for Photosynthesis) and strong reflection in the Near Infrared (Infrared energy is mostly reflected by plants due to their cellular structure). Due to its robustness and simplicity, NDVI has become one of the most popular remote sensing based products. Typically, a vegetation index is constructed in such a way that the attenuated reflected sunlight energy (1% to 30% of incident sunlight) is amplified by ratio-ing red and NIR following this equation:
The evolution of the vegetation index through time, depicted by the graph above, exhibits a strong correlation with the typical green vegetation growth stages (emergence, vigor/growth, maturity, and harvest/senescence). These temporal curves are analyzed to extract useful parameters about the vegetation growing season (start of season, end of season, length of growing season, etc.). Other growing season parameters could potentially be extracted, and global maps of any of these growing season parameters could then be constructed and used in all sorts of climatic change studies.
A noteworthy example of the use of remote sensing based phenology is the work of Ranga Mynenifrom Boston University. This work showed an apparent increase in vegetation productivity that most likely resulted from the increase in temperature and lengthening of the growing season in the boreal forest. Another example based on the MODIS enhanced vegetation index (EVI) reported by Alfredo Huete at the University of Arizona and colleagues showed that the Amazon Rainforest, as opposed to the long-held view of a monotonous growing season or growth only during the wet rainy season, does in fact exhibit growth spurts during the dry season.
However, these phenological parameters are only an approximation of the true biological growth stages. This is mainly due to the limitation of current space-based remote sensing, especially the spatial resolution, and the nature of vegetation index. A pixel in an image does not contain a pure target (like a tree, a shrub, etc.) but contains a mixture of whatever intersected the sensor's field of view.
Most species, including both plants and animals, interact with one another within ecosystems and habitats, known as biological interactions.These interactions (whether it be plant-plant, animal-animal, predator-prey or plant-animal interactions) can be vital to the success and survival of populations and therefore species.
Many species experience changes in life cycle development, migration or in some other process/behavior at different times in the season than previous patterns depict due to warming temperatures. Phenological mismatches, where interacting species change the timing of regularly repeated phases in their life cycles at different rates, creates a mismatch in interaction timing and therefore negatively harming the interaction.Mismatches can occur in many different biological interactions, including between species in one trophic level (intratrophic interactions) (ie. plant-plant), between different trophic levels (intertrophic interactions) (ie. plant-animal) or through creating competition (intraguild interactions). For example, if a plant species blooms its flowers earlier than previous years, but the pollinators that feed on and pollinate this flower does not arrive or grow earlier as well, then a phenological mismatch has occurred. This results in the plant population declining as there are no pollinators to aid in their reproductive success. Another example includes the interaction between plant species, where the presence of one specie aids in the pollination of another through attraction of pollinators. However, if these plant species develop at mismatched times, this interaction will be negatively affected and therefore the plant species that relies on the other will be harmed.
Phenological mismatches means the loss of many biological interactions and therefore ecosystem functions are also at risk of being negatively effects or lost all together. Phenological mismatches his will effect species and ecosystems food webs, reproduction success, resource availability, population and community dynamics in future generations, and therefore evolutionary process and overall biodiversity.
An urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the urban heat island effect is from the modification of land surfaces. Waste heat generated by energy usage is a secondary contributor. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.
A meadow is an open habitat, or field, vegetated by grass, herbs and other non-woody plants. Meadows may be sparsely covered with trees or shrubs, as long as they maintain an open character. They may be naturally occurring or artificially created from cleared shrub or woodland. They can occur naturally under favourable conditions, but they are often maintained by humans for the production of hay, fodder or livestock. Meadow habitats, as a group, are characterized as 'semi-natural grasslands', meaning that they are largely composed of species native to the region, with only limited human intervention.
Campanula rotundifolia, the harebell, Scottish bluebell, or bluebell of Scotland, is a species of flowering plant in the bellflower family Campanulaceae. This herbaceous perennial is found throughout the temperate regions of the northern hemisphere. In Scotland, it is often known simply as bluebell. It is the floral emblem of Sweden where it is known as small bluebell. It produces its violet-blue, bell-shaped flowers in late summer and autumn.
Alpine plants are plants that grow in an alpine climate, which occurs at high elevation and above the tree line. There are many different plant species and taxon that grow as a plant community in these alpine tundra. These include perennial grasses, sedges, forbs, cushion plants, mosses, and lichens. Alpine plants are adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, wind, drought, poor nutritional soil, and a short growing season.
In phenology, season creep refers to observed changes in the timing of the seasons, such as earlier indications of spring widely observed in temperate areas across the Northern Hemisphere. Phenological records analyzed by climate scientists have shown significant temporal trends in the observed time of seasonal events, from the end of the 20th century and continuing into the 21st century. In Europe, season creep has been associated with the arrival of spring moving up by approximately one week in a recent 30-year period. Other studies have put the rate of season creep measured by plant phenology in the range of 2–3 days per decade advancement in spring, and 0.3–1.6 days per decade delay in autumn, over the past 30–80 years.
Charles François Antoine Morren, was a Belgian botanist and horticulturist, and Director of the Jardin botanique de l’Université de Liège.
Climate change is any significant long term change in the expected pattern, whether due to natural variability or as a result of human activity. Environmental conditions play a key role in defining the function and distribution of plants, in combination with other factors. Changes in long term environmental conditions that can be collectively coined climate change are known to have had enormous impacts on current plant diversity patterns; further impacts are expected in the future. It is predicted that climate change will remain one of the major drivers of biodiversity patterns in the future. Human actions are currently triggering the sixth major mass extinction our Earth has seen, changing the distribution and abundance of many plants.
The International Tundra Experiment (ITEX) is a long-term international collaboration of researchers examining the responses of arctic and alpine plants and ecosystems to climate change. Researchers measure plant responses to standardized, small-scale passive warming, snow manipulations, and nutrient additions. Researchers use small open-top chambers (OTCs) to passively increase mean air temperature by 1-2 °C. The ITEX approach has been validated by tundra responses at the plot level. The network has published meta-analyses on plant phenology, growth, and reproduction, composition and abundance, and carbon flux.
Climate change has adversely affected both terrestrial and marine ecosystems, and is expected to further affect many ecosystems, including tundra, mangroves, coral reefs, and caves. Increasing global temperature, more frequent occurrence of extreme weather, and rising sea level are among some of the effects of climate change that will have the most significant impact. Some of the possible consequences of these effects include species decline and extinction, behavior change within ecosystems, increased prevalence of invasive species, a shift from forests being carbon sinks to carbon sources, ocean acidification, disruption of the water cycle, and increased occurrence of natural disasters, among others.
Climate change in recent times has become a major issue and talking point globally because of its effects on the environment and the repercussions this could be having or possibly have. The effects of climate change on Viniculture are described in this article.
Lakshminarayanapuram Ananthakrishnan Ramdas was an Indian physicist and meteorologist, known for discovering the atmospheric phenomenon of the Ramdas layer or Lifted Temperature Minimum where the lowest temperature in the atmosphere is not on the ground but a few tens of centimeters above the ground resulting. This can be seen in thin layer fogs which are at some height above the ground. He has been called the father of agricultural meteorology in India.
The match/mismatch hypothesis (MMH) was first described by David Cushing (1969). The MMH "seeks to explain recruitment variation in a population by means of the relation between its phenology—the timing of seasonal activities such as flowering or breeding - and that of species at the immediate lower level", see Durant et al. (2007). In essence it is a measure of reproductive success due to how well the phenology of the prey is able to meet the requirements of its predator. In ecological studies, a few examples include; the seasonal occurrence of breeding bird species to that of their primary prey, the interactions between herring fish reproduction and copepod spawning, or the relationship between winter moth egg hatching, and the timing of oak bud bursting.
Climate change has a significant direct effect on terrestrial animals, by being a major driver of the processes of speciation and extinction. The best known example of this is the Carboniferous rainforest collapse, which occurred 305 million years ago. This event decimated amphibian populations and spurred on the evolution of reptiles. In general, climate change affects animals and birdlife in various different ways. Birds lay their eggs earlier than usual in the year, plants bloom earlier and mammals come out of their hibernation state earlier.
The effects of climate change in Saskatchewan are now being observed in parts of the province. There is evidence of reduction of biomass in Saskatchewan's boreal forests that is linked by researchers to drought-related water stress stemming from global warming, most likely caused by greenhouse gas emissions. While studies, as early as 1988 have shown that climate change will affect agriculture, whether the effects can be mitigated through adaptations of cultivars, or crops, is less clear. Resiliency of ecosystems may decline with large changes in temperature. The provincial government has responded to the threat of climate change by introducing a plan to reduce carbon emissions, "The Saskatchewan Energy and Climate Change Plan", in June 2007.
Flowering synchrony is the amount of overlap between flowering periods of plants in their mating season compared to what would be expected to occur randomly under given environmental conditions. A population which is flowering synchronously has more plants flowering at the same time than would be expected to occur randomly. A population which is flowering asynchronously has fewer plants flowering at the same time than would be expected randomly. Flowering synchrony can describe synchrony of flowering periods within a year, across years, and across species in a community. There are fitness benefits and disadvantages to synchronized flowering, and it is a widespread phenomenon across pollination syndromes.
Anthropocentric climate change has been found to bring about the increase in temperature and precipitation in a range of ecosystems. The drastic change of these climate factors is predicted to progress leading to the destabilization of ecosystems. Human-caused climate change and the rise in invasive species are directly linked through changing of ecosystems. The destabilization of climate factors in these ecosystems can lead to the creation of a more hospitable habitat for invasive species- species that not historically found in the impacted regions. Thus, invasive species are able to spread beyond their original boundaries. This relationship is notable because climate change and invasive species are also considered by the USDA to be two of the top four causes of global biodiversity loss.
The Plant Phenology Ontology (PPO) is a collection of OBO Foundry ontologies that facilitate integration of heterogeneous data about seed plant phenology from various sources. These data sources include observations networks, such as the National Ecological Observatory Network (NEON), the National Phenology Network (NPN), and the Pan-European Phenology Database (PEP725), remote sensing, herbarium specimens, and citizen science observations. The initial focus during ontology development was to capture phenological data about one plant or a population of plants as observed by a person, and this enabled integration of data across disparate observation network sources. Because phenological scorings vary in their methods and reporting, this allows these data to be aggregated and compared. Changes in plant phenology can be linked to different climate factors depending on the species, such precipitation or growing degree days. Aggregated data about the timing of plant life cycle stages at different places and times can provide information about spatiotemporal patterns within and among species, and potentially offer insight into how plants may change or shift their life cycles in response to climate change. These shifts can have implications for agriculture and various biodiversity research avenues, such as shifts in pollinator and host life cycles.
Human caused global warming is predicted to have severe effects on birds.
Allochronic speciation is a form of speciation arising from reproductive isolation that occurs due to a change in breeding time that reduces or eliminates gene flow between two populations of a species. The term allochrony is used to describe the general ecological phenomenon of the differences in phenology that arise between two or more species—speciation caused by allochrony is effectively allochronic speciation.
Nuolja, also known as Njulla, is a field research site in Sweden that stretches across Mt. Njulla. With the mountain to the east, the village of Abisko to the south, and bordering Lake Torneträsk, this is a varied-habitat field site. Mountain birch forests are one of the main appeals of this research site.
Phenological grape harvest observations in Switzerland over the last 500 years have been used as a proxy indicator for reconstructing past temperature variability.
Phenological grape harvest observations in Switzerland over the last 500 years have been used as a proxy indicator for reconstructing past temperature variability.
One of the preferred indicators is phenology, the science of natural recurring events, as their recorded dates provide a high-temporal resolution of ongoing changes.
SI first leaf dates, measuring change in the start of ‘early spring’ (roughly the time of shrub budburst and lawn first greening), are getting earlier in nearly all parts of the Northern Hemisphere. The average rate of change over the 1955–2002 period is approximately -1.2 days per decade.