Alterations In Phenology Research Articles

Crop Coefficients and Irrigation Demand in Response to Climate-Change-Induced Alterations in Phenology and Growing Season of Vegetable Crops

This study investigates the effects of climate change on the irrigation demand of vegetable crops caused by alteration of climate parameters affecting evapotranspiration (ET), plant development, and growing periods in Central Europe. Utilizing a model framework comprising two varying climate scenarios (RCP 2.6 and RCP 8.5) and two regional climate models (COSMO C-CLM and WETTREG 2013), we calculate the daily crop water balance (CWBc) as a measure for irrigation demand based on reference ET and the temperature-driven duration of crop coefficients until 2100. Our findings for onion show that rising temperatures may shorten cultivation periods by 5 to 17 days; however, the irrigation demand may increase by 5 to 71 mm due to higher ET. By reaching the base temperatures for onion growth earlier in the year, cultivation start can be advanced by up to 30 days. Greater utilization of winter soil moisture reduces the irrigation demand by up to 21 mm, though earlier cultivation is restricted by frost risks. The cultivation of thermophilic crops, however, cannot be advanced to the same extent, as shown for bush beans, and plants will transpire more strongly due to longer dry periods simulated for summer. The results underscore the need for adaptive crop and water management strategies to counteract the simulated changes in phenology and irrigation demand of vegetable crops. Therefore, special consideration must be given to the regional-specific and model- and scenario-dependent simulation results.

Drought decreased annual cumulative carbon uptake in Southwest China mainly through its influence on phenology rather than physiology

Drought poses a significant threat to the sustainability of ecosystems, particularly in regions like Southwest China, where it has been observed to substantially reduce the annual cumulative carbon uptake (ACCU). Understanding the mechanisms driving this reduction is therefore crucial for effective ecosystem management. To address this issue, this study decomposed ACCU into three indicators, i.e., start of the growing season (SOS), end of the growing season (EOS), and peak gross primary productivity (GPPmax), through the Statistical Model of Integrated Phenology and Physiology (SMIPP), and explored the response of ACCU to drought. The results revealed that phenology (SOS and EOS) and physiology (GPPmax) components collectively captured 74% of the variation in ACCU, confirming the applicability of the SMIPP model in Southwest China. Among the three indicators, GPPmax contributes to ACCU more than the two phenological indicators. We also found that, from 2001 to 2020, drought decreased ACCU by 65.58 Tg C through delying SOS, by 21.47 Tg C through advancing EOS, but increased ACCU by 11.15 Tg C through increasing GPPmax, resulting in a net loss of 75.90 Tg C in ACCU. Our findings highlight the predominant negative impact of drought on ACCU, achieved primarily through alterations in phenology. Overall, this study quantified the respective contributions of phenology and physiology in the response of ACCU to drought, and would inform the prediction of ACCU of ecosystems under future drought in Southwest China.

Rapid formation of new migration route and breeding area by Arctic geese

Many Arctic-breeding animals are at risk from local extirpation associated with habitat constriction and alterations in phenology in their Arctic environment as a result of rapid global warming.1 Migratory species face additional increasing anthropogenic pressures along their migratory routes such as habitat destruction, droughts, creation of barriers, and overexploitation.2,3 Such species can only persist if they adjust their migration, timing of breeding, and range.4 Here, we document both the abrupt (∼10 years) formation of a new migration route and a disjunct breeding population of the pink-footed goose (Anser brachyrhynchus) on Novaya Zemlya, Russia, almost 1,000km away from the original breeding grounds in Svalbard. The population has grown to 3,000-4,000 birds, explained by intrinsic growth and continued immigration from the original route. The colonization was enabled by recent warming on Novaya Zemlya. We propose that social behavior of geese, resulting in cultural transmission of migration behavior among conspecifics as well as in mixed-species flocks, is key to this fast development and acts as a mechanism enabling ecological rescue in a rapidly changing world.

Resiliency of the Butterfly Fauna (Papilionoidea and Hesperioidea) at Roxborough State Park, Colorado: Long-Term and Short-Term Alterations in Phenology and Species Presence

The butterfly assemblage at Roxborough State Park, Douglas County, Colorado was examined for long-term and short-term changes over 41 years. Seven surveys occurred between 1979–1995 (=historic) with more recent surveys in 2018 and 2019. We compared flight phenology and species assemblages between these periods. Increased monthly species richness in 2018-2019 may have been related to decreased grazing and/or climate change. Additional species were noted in 2018 and 2019, however, some species from 1979 to 1995 went undetected. In most cases, species detected on a very common (VC) basis (calculated from interquartile ranges) between 1979 and 1995 were still VC in 2018–2019. Long-term temperature data (1979-2019) indicated a significant increase over time in winter temperatures. VC species mostly had earlier dates of first flight (DFF) in 2018 compared to historic. However, 2019 DFF's were later. Temperatures differed significantly between 2018 and 2019, with lower winter and spring temperatures in 2019. Eight species were newly detected in 2018-2019. Three of these: Erynnis horatius, Speyeria coronis, and Polites themistocles, were found in both years suggesting they are persistent members of the Roxborough assemblage. Including historical surveys, the Roxborough species list stands at 102. Perhaps surprisingly during times that suggest a decline of insects, including butterflies, Roxborough State Park has shown a degree of resiliency. We will suggest reasons for this apparent persistence.

Multiple temperature effects on phenology and body size in wild butterflies predict a complex response to climate change.

Temperature-induced alterations in phenology and body size are the cumulative outcome of sequential effects impacting development and are universal responses to climate change. Most studies have so far focused on phenological responses to warming in multiple taxa across space and time, or the ontogenetic effects of temperature in the laboratory. I here complement this work by investigating shifts in phenology and body size (wing length) attributable to temperature changes operating over the entire lifespan of the univoltine orange-tip butterfly Anthocharis cardamines in a single wild population over 14 generations. Phenology was affected by temperatures during three discrete periods in the year prior to emergence, corresponding to late larval/early pupal life, the onset of the chilling period required to break pupal diapause, and postdiapause pupal development prior to eclosion. Higher temperatures during late larval/early pupal life and postdiapause pupal development advanced the subsequent emergence of the butterflies, whereas higher temperatures at the onset of the chilling period retarded it. The synchronization of the butterflies' emergence schedule increased when pupae were exposed to milder midwinter temperatures. Wing length increased with warmer temperatures at distinct points in the early and midpupal periods; such direct effects of temperature on body size could complement season length effects in explaining the reversal of the temperature-size rule in univoltine insects. The periods during which temperature affected the phenology of the butterfly only partially overlapped those affecting the first flowering date of its host plants lady's smock (Cardamine pratensis) and garlic mustard (Alliaria petiolata). Observed thermal effects on flowering time, emergence timing, and emergence synchronization indicate that phenological convergence as well as phenological mismatching could affect host-plant availability and diet breadth; thermal effects on body size imply that important population-level processes could be impacted through correlated changes in fecundity and dispersal rate. In general, the combined effects of phenological and ontogenetic responses to temperature changes across the whole lifespan will likely be important in modeling the demographic responses of interacting species to climate change.

Cambio climático y sus efectos en la vegetación de Veracruz, México: una aproximación mediante modelado de nicho ecológico

De acuerdo con el último informe del Panel Intergubernamental sobre Cambio Climático, las actividades humanas son las principales responsables del calentamiento global observado en las últimas décadas y se debe al incremento en la concentración atmosférica de gases de efecto invernadero. Este proceso ya está causando cambios en la distribución geográfica de las especies, así como alteraciones en la fenología. En tal contexto, es interesante estudiar las posibles tendencias de cambio que podrían presentar la flora y fauna para hacer frente a las nuevas condiciones del medio ambiente. En este trabajo se exploran los posibles cambios en la composición de los principales tipos de vegetación en el estado de Veracruz, México, ante un escenario de cambio climático, mediante el análisis de los patrones de alteración geográfica y ecológica de un grupo de 51 especies comúnmente asociadas al bosque tropical perennifolio, el bosque de coníferas y el bosque mesófilo de montaña, presentes en el estado. El enfoque adoptado se basa en la técnica de modelado de nicho ecológico realizado con el Algoritmo Genético para la Producción de grupos de Reglas (GARP) y variables climatológicas estimadas para un escenario A2 que corresponde a una humanidad que genera emisiones medias-altas y derivan de proyecciones hechas a partir de las condiciones actuales hacia el año 2050. Los resultados obtenidos para la superficie actual de la vegetación del estado de Veracruz sugieren una afectación potencial de 53% del área de distribución para el bosque tropical perennifolio, de 16% para el bosque de coníferas y de 49% para el bosque mesófilo de montaña. Además, apuntan a que algunas especies tienen alta probabilidad de resultar extirpadas de la entidad bajo las condiciones esperadas en el 2050, mientras que otras encontrarán las condiciones adecuadas para incrementar su distribución.

Intraspecific functional trait variability does not result in higher fitness under thermal stress in a free-living marine nematode

Climate change has an impact on all levels of biodiversity: genes, species, populations and ecosystems. This effect is expected to be dependent on the rate of change. When faced with unfavorable environmental conditions, individuals have three non-exclusive options by which they can mitigate these changes: temporal alterations in phenology, spatial tracking of optimal conditions or in situ adaptation. For the latter to occur requires the existence of variability among conspecifics with respect to traits that directly or indirectly influence individual performance and fitness. One such “functional” trait is thermal stress tolerance. We investigated the presence of intraspecific functional trait variability of isofemale lineages of the free-living marine nematode Litoditis marina in monoculture, double and quadruple mixtures under thermal stress, which was applied in a gradient and a sudden treatment over 20days, corresponding to at least four generations. We found a high degree of intraspecific functional trait variability relevant to thermal tolerance. This type of variability has traditionally been considered negligible compared to interspecific variation, but our results demonstrate the importance of its inclusion within trait-based eco-evolutionary studies as this will confer increased accuracy when inputting physiological parameters to relevant models (e.g. species distribution models). Additionally, we found a significant effect of the temperature treatments. In accordance with the majority of experimental evidence, our populations showed a stronger response to a sudden versus a gradient increase in temperature. Contrary to our expectations, no significant differences were observed between monocultures, double and quadruple lineage mixtures suggesting that increased intraspecific trait variability did not lead to higher fitness in L. marina populations exposed to thermal stress.

English

Low temperature is one of the main abiotic stresses affecting rice yield in Chile. Alterations in phenology and physiology of the crop are observed after a cold event. The objective of this work was to study the relative expression of genes related with cold stress in Chilean cultivars of rice. For this, we analyzed the expression of candidate genes using real-time polymerase chain reaction (rtPCR), after exposure to cold of the rice cultivars Diamante-INIA and Zafiro-INIA and one experimental line from INIA´s Rice Breeding Program in Chile, Quila 241701, with known high cold tolerance. For analysis, the Spanish cultivar, Susan, was used as check tolerance and Oryzica 1 as susceptible check. Oxidative stress was measured through lipid peroxidation. To find mechanisms of cold tolerance in Chilean cultivars, we determined the relative expression of genes related with oxidative stress, such as superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT). Lipid peroxidation allowed the measurement of the physiological stress level of the genotypes under study. The results indicate that lipid peroxidation in Oryzica 1 was higher than in the other genotypes. No differences were observed in expression levels of gene-encoding SOD and GR between genotypes. Contrary to expected results, high level of the gene-encoding CAT enzyme in Oryzica 1 after cold stress was observed. Future experiment, related with enzymatic activity and non-enzymatic antioxidant mechanism, are necessary to elucidate the relationship between cold stress and expression levels of gene-encoding antioxidant enzyme in Chilean rice germplasm.   Key words: Cold stress, reactive oxygen species, antioxidant enzymes.

Clinal variation for only some phenological traits across a species range

Phenology is the timing of life cycle events of an organism. Alterations in phenology can have profound effects on individual fitness, population growth, and community dynamics. Recent changes in climate have altered the phenology of many organisms, which may result in selection to shift phenological traits. Understanding the relationship between local climates and population differentiation in phenology will allow us to anticipate responses to novel selective environments caused by global climate change. We evaluated population differentiation in the number of days to germination, first flower, and fruit maturation for 33 populations throughout the range of Campanulastrum americanum (American Bellflower). Germination and fruit maturation had geographical clines with earlier timing in populations from northern latitudes. Northern sites were cooler and drier, suggesting potential adaptive differentiation of the shorter life cycle associated with earlier phenology. Similarly, higher elevations were cooler and had earlier fruit maturation. However, seed germination was later in higher elevation populations. Although there was substantial variation in the day to first flower, ranging 40 days between population means, it was idiosyncratic and not related to latitude, suggesting differentiation in response to selective factors distinct from those on germination and fruit maturation. Thus, germination and fruit maturation in C. americanum may shift in response to selection by rising temperatures. However, such changes are not expected for flowering time, a typical indicator of climate change.

Changes in snowmelt date and summer precipitation affect the flowering phenology of Erythronium grandiflorum (glacier lily; Liliaceae)

Climate change has affected species worldwide, including alterations in phenology, migration patterns, distribution, and survival. Because Erythronium grandiflorum is an early-season bloomer, alterations in its phenology may have serious implications for many North American Rocky Mountain communities, including changes in resource availability for pollinators and herbivores. • We investigated whether changes in the snowmelt date, summer temperature, and summer precipitation have altered the timing and abundance of flowering in E. grandiflorum by collecting long-term data on floral abundance from 1975-2008 in a series of 2 × 2 m plots at the Rocky Mountain Biological Laboratory (RMBL) in Gothic, Colorado in the United States. • Snowmelt date and mean summer temperature were negatively correlated. Over the 30-yr study, the snowmelt date advanced by 4.14 d/decade, and mean summer temperature increased by 0.38°C/decade. Summer precipitation was variable, showing no change. The first, peak, and last flowering dates of E. grandiflorum advanced an average of 3.2 d/decade. Furthermore, earlier snowmelt and greater summer precipitation in the previous year led to earlier flowering in E. grandiflorum. There was no change in flowering abundance in this species, indicating it may be controlled by a complex set of abiotic and biotic variables. • Our study indicates that snowmelt is arriving earlier at the RMBL, which has caused earlier flowering in E. grandiflorum. Because alterations in phenology can disrupt important ecological interactions, information on potential phenological shifts in species that interact with E. grandiflorum is essential in determining the net effect of climate-driven alterations in phenology.