Warmer Nighttime Temperatures Research Articles

Occurrence of crop pests and diseases has largely increased in China since 1970.

Crop pests and diseases (CPDs) are emerging threats to global food security, but trends in the occurrence of pests and diseases remain largely unknown due to the lack of observations for major crop producers. Here, on the basis of a unique historical dataset with more than 5,500 statistical records, we found an increased occurrence of CPDs in every province of China, with the national average rate of CPD occurrence increasing by a factor of four (from 53% to 218%) during 1970-2016. Historical climate change is responsible for more than one-fifth of the observed increment of CPD occurrence (22% ± 17%), ranging from 2% to 79% in different provinces. Among the climatic factors considered, warmer nighttime temperatures contribute most to the increasing occurrence of CPDs (11% ± 9%). Projections of future CPDs show that at the end of this century, climate change will lead to an increase in CPD occurrence by 243% ± 110% under a low-emissions scenario (SSP126) and 460% ± 213% under a high-emissions scenario (SSP585), with the magnitude largely dependent on the impacts of warmer nighttime temperatures and decreasing frost days. This observation-based evidence highlights the urgent need to accurately account for the increasing risk of CPDs in mitigating the impacts of climate change on food production.

Urban thermal perception and self-reported health effects in Ibadan, south west Nigeria.

The ability of poor urban populations in developing countries to adapt to rapid increase in surface temperature and likely health effect of a 1.5°C increase in global temperature is uncertain. Rapid urbanization and poor socio, economic, and technological development may increase heat vulnerabilities of poor urban populations in tropical cities. This study examines the thermal perception of urban populations in Ibadan, south western Nigeria, and sociodemographic characteristics of individuals that influence thermal perception, self-reported health effects, and coping strategies to heat stress using a purposefully designed questionnaire and interviews with aged individuals in the five local government areas of Ibadan metropolis. Differences in sociodemographic characteristics of respondents such as inequalities in monthly income, occupation, ethnicity, housing characteristics, and length of stay in Ibadan significantly influence thermal perception, self-reported health effects of heat exposure, and coping strategies adopted. Perceived thermal conditions reported were warmer temperatures during the day and night (43.75%), warmer day-time temperatures (40.25%), and warmer night-time temperatures (16%). Dehydration and sweating (56%): heat rash, heat exhaustion, headaches, sleep disturbances and dehydration (15.25%), and sleep disturbance and sweating (12.25%) were major combinations of self-reported health effects. Other effects include fainting, diarrhea, raised blood pressure, and restlessness. Temperature variations (minimum and maximum) examined from 1971 to 2018 shows that warmer conditions are being experienced in Ibadan. Increased heat-health awareness and urban designs that respond to people's thermal perception should be encouraged in developing thermally comfortable environments in Ibadan.

Warm nights disrupt transcriptome rhythms in field-grown rice panicles

In rice, a small increase in nighttime temperature reduces grain yield and quality. How warm nighttime temperatures (WNT) produce these detrimental effects is not well understood, especially in field conditions where the typical day-to-night temperature fluctuation exceeds the mild increase in nighttime temperature. We observed genome-wide disruption of gene expression timing during the reproductive phase in field-grown rice panicles acclimated to 2 to 3 °C WNT. Transcripts previously identified as rhythmically expressed with a 24-h period and circadian-regulated transcripts were more sensitive to WNT than were nonrhythmic transcripts. The system-wide perturbations in transcript levels suggest that WNT disrupt the tight temporal coordination between internal molecular events and the environment, resulting in reduced productivity. We identified transcriptional regulators whose predicted targets are enriched for sensitivity to WNT. The affected transcripts and candidate regulators identified through our network analysis explain molecular mechanisms driving sensitivity to WNT and identify candidates that can be targeted to enhance tolerance to WNT.

Bolometric bond albedo and thermal inertia maps of Mimas

In 2011 a thermally anomalous region was discovered on Mimas, Saturn's innermost major icy satellite (Howett et al., 2011). The anomalous region is a lens-like shape located at low latitudes on Mimas' leading hemisphere. It manifests as a region with warmer nighttime temperatures, and cooler daytime ones than its surroundings. The thermally anomalous region is spatially correlated with a darkening in Mimas' IR/UV surface color (Schenk et al., 2011) and the region preferentially bombarded by high-energy electrons (Paranicas et al., 2012, 2014; Nordheim et al., 2017).We use data from Cassini's Composite Infrared Spectrometer (CIRS) to map Mimas' surface temperatures and its thermophysical properties. This provides a dramatic improvement on the work in Howett et al. (2011), where the values were determined at only two regions on Mimas (one inside, and another outside of the anomalous region). We use all spatially-resolved scans made by CIRS' focal plane 3 (FP3, 600 to 1100 cm−1) of Mimas' surface, which are largely daytime observations but do include one nighttime one. The resulting temperature maps confirm the presence and location of Mimas' previously discovered thermally anomalous region. No other thermally anomalous regions were discovered, although we note that the surface coverage is incomplete on Mimas' leading and anti-Saturn hemisphere. The thermal inertia map confirms that the anomalous region has a notably higher thermal inertia than its surroundings: 98 ± 42 J m−2 K−1 s-1/2 inside of the anomaly, compared to 34 ± 32 J m−2 K−1 s-1/2 outside. The albedo inside and outside of the anomalous region agrees within their uncertainty: 0.45 ± 0.08 inside compared to 0.41 ± 0.07 outside the anomaly. Interestingly the albedo appears brighter inside the anomaly region, which may not be surprising given this region does appear brighter at some UV wavelengths (0.338 μm, see Schenk et al., 2011). However, this result should be treated with caution because, as previously stated, statistically the albedo of these two regions is the same when their uncertainties are considered. These thermal inertia and albedo values determined here are consistent with those found by Howett et al. (2011), who determined the thermal inertia inside the anomaly to be 66 ± 23 J m−2 K−1 s-1/2 and <16 J m−2 K−1 s-1/2 outside, with albedos that varied from 0.49 to 0.70.

A mass participatory experiment provides a rich temporal profile of temperature response in spring onions.

Plants modulate their growth rates based on the environmental signals; however, it is difficult to experimentally test how natural temperature and light fluctuations affect growth, since realistic outdoor environments are difficult to replicate in controlled laboratory conditions, and it is expensive to conduct experiments in many environmentally diverse regions. In partnership with BBC Terrific Scientific, over 50 primary schools from around the UK grew spring onions outside of hydroponic growth chambers that they constructed. Over 2 weeks, students measured the height of the spring onions daily, while the hourly temperature and visibility data were determined for each school based on the UK Meteorological Office data. This rich time series data allowed us to model how plants integrate temperature and light signals to determine how much to grow, using techniques from functional data analysis. We determined that under nutrient‐poor hydroponic conditions, growth of spring onion is sensitive to even a few degrees change in temperature, and is most correlated with warm nighttime temperatures, high temperatures at the start of the experiment, and light exposure near the end of the experiment. We show that scientists can leverage schools to conduct experiments that leverage natural environmental variability to develop complex models of plant‐environment interactions.

Modeling canopy-induced turbulence in the Earth system: a unified parameterization of turbulent exchange within plant canopies and the roughness sublayer (CLM-ml v0)

Abstract. Land surface models used in climate models neglect the roughness sublayer and parameterize within-canopy turbulence in an ad hoc manner. We implemented a roughness sublayer turbulence parameterization in a multilayer canopy model (CLM-ml v0) to test if this theory provides a tractable parameterization extending from the ground through the canopy and the roughness sublayer. We compared the canopy model with the Community Land Model (CLM4.5) at seven forest, two grassland, and three cropland AmeriFlux sites over a range of canopy heights, leaf area indexes, and climates. CLM4.5 has pronounced biases during summer months at forest sites in midday latent heat flux, sensible heat flux, gross primary production, nighttime friction velocity, and the radiative temperature diurnal range. The new canopy model reduces these biases by introducing new physics. Advances in modeling stomatal conductance and canopy physiology beyond what is in CLM4.5 substantially improve model performance at the forest sites. The signature of the roughness sublayer is most evident in nighttime friction velocity and the diurnal cycle of radiative temperature, but is also seen in sensible heat flux. Within-canopy temperature profiles are markedly different compared with profiles obtained using Monin–Obukhov similarity theory, and the roughness sublayer produces cooler daytime and warmer nighttime temperatures. The herbaceous sites also show model improvements, but the improvements are related less systematically to the roughness sublayer parameterization in these canopies. The multilayer canopy with the roughness sublayer turbulence improves simulations compared with CLM4.5 while also advancing the theoretical basis for surface flux parameterizations.

A New Daily Observational Record from Grytviken, South Georgia: Exploring Twentieth-Century Extremes in the South Atlantic

The sparse nature of observational records across the mid- to high latitudes of the Southern Hemisphere limits the ability to place late-twentieth-century environmental changes in the context of long-term (multidecadal and centennial) variability. Historical records from subantarctic islands offer considerable potential for developing highly resolved records of change. In 1905, a whaling and meteorological station was established at Grytviken on subantarctic South Georgia in the South Atlantic (54°S, 36°W), providing near-continuous daily observations through to present day. This paper reports a new, daily observational record of temperature and precipitation from Grytviken, which is compared to regional datasets and historical reanalysis. The authors find a shift toward increasingly warmer daytime extremes commencing from the mid-twentieth century and accompanied by warmer nighttime temperatures, with an average rate of temperature rise of 0.13°C decade−1 over the period 1907–2016 ( p &lt; 0.0001). Analysis of these data and reanalysis products suggest a change of pervasive synoptic conditions across the mid- to high latitudes since the mid-twentieth century, characterized by stronger westerly airflow and associated warm föhn winds across South Georgia. This rapid rate of warming and associated declining habitat suitability has important negative implications for biodiversity, including the survival of key marine biota in the region.

Ecosystem-based climate change adaptation for Essenvelt, Middelburg, The Netherlands

Climate change is an internationally recognised phenomenon generally held accountable for the increasing magnitude of extremes in both climatic events and temperature. With increasing urbanization and the concentration of socio-economic activities in urban areas, the challenge to contend with climate change is particularly pertinent in cities. In response to climate-change impacts, a range of climateadaptation strategies have been developed to make cities increasingly ‘climate proof’. A qualitative research approach is employed to review climate change, its impacts and some adaptation strategies, focusing on ecosystem-based adaptation strategies from Belgium and The Netherlands and Water-Sensitive Urban Design approaches developed in Australia. The article engages a case study of Essenvelt, Middelburg, The Netherlands, where unanticipated warmer night-time temperatures are a primary concern, related to natural variability, the urban heat island effect and climate change. The article proposes certain adaptation measures for Essenvelt, based on the adaptation strategies reviewed. Keywords: Adaptation, climate change, ecosystem-based, water-sensitive urban design, WSUD

The global surface temperatures of the Moon as measured by the Diviner Lunar Radiometer Experiment

The Diviner Lunar Radiometer Experiment onboard the Lunar Reconnaissance Orbiter (LRO) has been acquiring solar reflectance and mid-infrared radiance measurements nearly continuously since July of 2009. Diviner is providing the most comprehensive view of how regoliths on airless bodies store and exchange thermal energy with the space environment. Approximately a quarter trillion calibrated radiance measurements of the Moon, acquired over 5.5 years by Diviner, have been compiled into a 0.5° resolution global dataset with a 0.25h local time resolution. Maps generated with this dataset provide a global perspective of the surface energy balance of the Moon and reveal the complex and extreme nature of the lunar surface thermal environment. Our achievable map resolution, both spatially and temporally, will continue to improve with further data acquisition.Daytime maximum temperatures are sensitive to the albedo of the surface and are ∼387–397K at the equator, dropping to ∼95K just before sunrise, though anomalously warm areas characterized by high rock abundances can be > 50K warmer than the zonal average nighttime temperatures. An asymmetry is observed between the morning and afternoon temperatures due to the thermal inertia of the lunar regolith with the dusk terminator ∼30K warmer than the dawn terminator at the equator. An increase in albedo with incidence angle is required to explain the observed decrease in temperatures with latitude. At incidence angles exceeding ∼40°, topography and surface roughness influence temperatures resulting in increasing scatter in temperatures and anisothermality between Diviner channels.Nighttime temperatures are sensitive to the thermophysical properties of the regolith. High thermal inertia (TI) materials such as large rocks, remain warmer during the long lunar night and result in anomalously warm nighttime temperatures and anisothermality in the Diviner channels. Anomalous maximum and minimum temperatures are highlighted by subtracting the zonal mean temperatures from maps. Terrains can be characterized as low or high reflectance and low or high TI. Low maximum temperatures result from high reflectance surfaces while low minimum temperatures from low-TI material. Conversely, high maximum temperatures result from dark surface, and high minimum temperatures from high-TI materials.Impact craters are found to modify regolith properties over large distances. The thermal signature of Tycho is asymmetric, consistent with an oblique impact coming from the west. Some prominent crater rays are visible in the thermal data and require material with a higher thermal inertial than nominal regolith. The influence of the formation of the Orientale basin on the regolith properties is observable over a substantial portion of the western hemisphere despite its age (∼3.8Gyr), and may have contributed to mixing of highland and mare material on the southwest margin of Oceanus Procellarum where the gradient in radiative properties at the mare-highland contact is broad (∼200km).

The deal with diel: Temperature fluctuations, asymmetrical warming, and ubiquitous metals contaminants

Climate projections over the next century include disproportionately warmer nighttime temperatures (“asymmetrical warming”). Cool nighttime temperatures lower metabolic rates of aquatic ectotherms. In contaminated waters, areas with cool nights may provide thermal refugia from high rates of daytime contaminant uptake. We exposed Cope's gray tree frogs (Hyla chrysoscelis), southern leopard frogs (Lithobates sphenocephalus), and spotted salamanders (Ambystoma maculatum) to five concentrations of a mixture of cadmium, copper, and lead under three to four temperature regimes, representing asymmetrical warming. At concentrations with intermediate toxicosis at test termination (96 h), temperature effects on acute toxicity or escape distance were evident in all study species. Asymmetrical warming (day:night, 22:20 °C; 22:22 °C) doubled or tripled mortality relative to overall cooler temperatures (20:20 °C) or cool nights (22:18 °C). Escape distances were 40–70% shorter under asymmetrical warming. Results suggest potentially grave ecological impacts from unexpected toxicosis under climate change.

Orchardgrass die‐off: How harvest management and heat stress may be reducing the persistence of orchardgrass hay stands

Orchardgrass die‐off: How harvest management and heat stress may be reducing the persistence of orchardgrass hay stands

Projections of heat waves with high impact on human health in Europe

Climate change will result in more intense, more frequent and longer lasting heat waves. The most hazardous conditions emerge when extreme daytime temperatures combine with warm night-time temperatures, high humidities and light winds for several consecutive days. Here, we assess present and future heat wave impacts on human health in Europe. Present daily physiologically equivalent temperatures (PET) are derived from the ERA-Interim reanalysis. PET allows to specifically focus on heat-related risks on humans. Regarding projections, a suite of high-resolution regional climate models – run under SRES A1B scenario – has been used. A quantile–quantile adjustment is applied to the daily simulated PET to correct biases in individual model climatologies and a multimodel ensemble strategy is adopted to encompass model errors. Two types of heat waves differently impacting human health – strong and extreme stress – are defined according to specified thresholds of thermal stress and duration. Heat wave number, frequency, duration and amplitude are derived for each type. Results reveal relatively strong correlations between the spatial distribution of strong and extreme heat wave amplitudes and mortality excess for the 2003 European summer. Projections suggest a steady increase and a northward extent of heat wave attributes in Europe. Strong stress heat wave frequencies could increase more than 40days, lasting over 20days more by 2075–2094. Amplitudes might augment up to 7°C per heat wave day. Important increases in extreme stress heat wave attributes are also expected: up to 40days in frequency, 30days in duration and 4°C in amplitude. We believe that with this information at hand policy makers and stakeholders on vulnerable populations to heat stress can respond more effectively to the future challenges imposed by climate warming.

Seasonal and diurnal patterns of speciated atmospheric mercury at a coastal-rural and a coastal-urban site

Gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particle-bound mercury (PBM) were monitored at a coastal-rural and a coastal-urban site in Nova Scotia, Canada from 2010 to 2011. The three-hour average urban concentrations were 1.67 ± 1.01 ng m−3, 2.1 ± 3.4 pg m−3 and 2.3 ± 3.1 pg m−3 for GEM, GOM and PBM, respectively. The rural site concentrations were 1.38 ± 0.20 ng m−3, 0.4 ± 1.0 pg m−3 and 3.5 ± 4.5 pg m−3, respectively. GEM and GOM concentrations were higher at the urban site in all seasons, while PBM was higher at the rural site in winter. Both sites observed higher GEM and PBM during colder seasons and higher GOM in spring. Seasonal diurnal patterns showed daytime increases and nighttime decreases in GEM, GOM, and PBM. Rural–urban site differences may be attributed to the urban heat island effect resulting in warmer nighttime temperatures and higher GEM concentrations, urban GEM emissions, and enhanced deposition in forested areas leading to faster rural GEM decreases. Wind speeds ≥4 and ≥8 km h−1 were associated with higher rural GEM and lower PBM at night, which could be due to downward mixing from the residual boundary layer and marine airflows from the open ocean as modeled by back trajectories. The back trajectory analysis also found higher rural GEM and lower PBM overnight at both sites for open ocean airflows than all airflow conditions, suggesting the ocean is a source of GEM but not PBM.

The variability of California summertime marine stratus: Impacts on surface air temperatures

AbstractThis study investigates the variability of clouds, primarily marine stratus clouds, and how they are associated with surface temperature anomalies over California, especially along the coastal margin. We focus on the summer months of June to September when marine stratus are the dominant cloud type. Data used include satellite cloud reflectivity (cloud albedo) measurements, hourly surface observations of cloud cover and air temperature at coastal airports, and observed values of daily surface temperature at stations throughout California and Nevada. Much of the anomalous variability of summer clouds is organized over regional patterns that affect considerable portions of the coast, often extend hundreds of kilometers to the west and southwest over the North Pacific, and are bounded to the east by coastal mountains. The occurrence of marine stratus is positively correlated with both the strength and height of the thermal inversion that caps the marine boundary layer, with inversion base height being a key factor in determining their inland penetration. Cloud cover is strongly associated with surface temperature variations. In general, increased presence of cloud (higher cloud albedo) produces cooler daytime temperatures and warmer nighttime temperatures. Summer daytime temperature fluctuations associated with cloud cover variations typically exceed 1°C. The inversion‐cloud albedo‐temperature associations that occur at daily timescales are also found at seasonal timescales.

Do Wind Turbines Affect Weather Conditions: A Case Study in Indiana

Wind turbines are becoming increasingly widespread in the United States as the world looks for cleaner sources of energy. Scientists, policymakers, and citizens have strong opinions regarding the positive and negative effects of wind energy projects, and there is a great deal of misinformation about wind energy circulating on the Web and other media sources. The purpose of this study is to gain a better understanding of how the rotation of hundreds of turbines can influence local weather conditions within a wind farm and in the surrounding areas. This experiment measures temperature, atmospheric pressure, wind speed, wind direction, relative humidity, and evaporation with five weather instruments at Meadow Lake Wind Farm located in White, Jasper, and Benton Counties, Indiana, from November 4 through November 18, 2010. The data show that as wind passes throughout the wind farm, the air warms during the overnight and early morning hours and cools during daytime hours. Observed lower humidity rates and higher evaporation rates downwind also demonstrate that the air dries out as it travels through the wind farm. Further research over multiple seasons is necessary to examine the effects of warmer nighttime temperatures and drier conditions progressively downwind of the installation. Nevertheless, wind turbines did not negatively affect local weather patterns in our small-scale research and may actually prevent frost, which could have important positive implications for farmers by potentially prolonging the growing season.

Consistent geographical patterns of changes in high-impact European heatwaves

Climate-change projections suggest that European summer heatwaves will become more frequent and severe during this century. An analysis of a set of high-resolution regional climate simulations reveals consistent geographical patterns in these changes, with the most severe health impacts in southern European river basins and along the Mediterranean coasts. Climate-change projections suggest that European summer heatwaves will become more frequent and severe during this century1,2,3,4, consistent with the observed trend of the past decades5,6. The most severe impacts arise from multi-day heatwaves, associated with warm night-time temperatures and high relative humidity. Here we analyse a set of high-resolution regional climate simulations and show that there is a geographically consistent pattern among climate models: we project the most pronounced changes to occur in southernmost Europe for heatwave frequency and duration, further north for heatwave amplitude and in low-altitude southern European regions for health-related indicators. For the Iberian peninsula and the Mediterranean region, the frequency of heatwave days is projected to increase from an average of about two days per summer for the period 1961–1990 to around 13 days for 2021–2050 and 40 days for 2071–2100. In terms of health impacts, our projections are most severe for low-altitude river basins in southern Europe and for the Mediterranean coasts, affecting many densely populated urban centres. We find that in these locations, the frequency of dangerous heat conditions also increases significantly faster and more strongly, and that the associated geographical pattern is robust across different models and health indicators.

Baseline Climatology of Viti Levu (Fiji) and Current Climatic Trends

In this paper we characterize the climate at Nadi and Suva in Fiji from 1961 to the present, providing a picture of ongoing climate trends. The focus is on surface observations of air temperature and rainfall, although some information on South Pacific Ocean climate is also discussed, given its relevance for Fiji. Our findings suggest that surface air temperatures have registered increasing trends at both Suva and Nadi (the two observatory sites in Fiji identified as Weather Observing Stations under the global network of the World Meteorological Organization) during the period 1961-2003. There has been a steady increase in the number of days per year with warmer nighttime temperatures in recent decades. The rise in annual mean surface air temperature over Suva was ∼1.2 °C over the 43-yr period considered here (at a significantly increasing rate of 0.25 °C per decade, which is 1.5 times higher than the trends in global average temperature increase during the past century). The rate of increase in annual mean surface air temperature at Nadi was 0.07 °C per decade. No trend in annual mean rainfall has been observed, however, at either of the locations. Significant interannual variability in annual as well as summer rainfall observed at both sites (including extreme rainfall events during the 43-yr period) can largely be attributed to El Niño-Southern Oscillation (ENSO) events and intraseasonal oscillations in the mean position of the South Pacific Convergence Zone.

Climate change impacts on agriculture and soil carbon sequestration potential in the Huang-Hai Plain of China

For thousands of years, the Huang-Hai Plain in northeast China has been one of the most productive agricultural regions of the country. The future of this region will be determined in large part by how global climatic changes impact regional conditions and by actions taken to mitigate or adapt to climate change impacts. One potential mitigation strategy is to promote management practices that have the potential to sequester carbon in the soils. The IPCC estimates that 40 Pg of C could be sequestered in cropland soils worldwide over the next several decades; however, changes in global climate may impact this potential. Here, we assess the potential for soil C sequestration with conversion of a conventional till (CT) continuous wheat system to a wheat–corn double cropping system and by implementing no till (NT) management for both continuous wheat and wheat–corn systems. To assess the influence of these management practices under a changing climate, we use two climate change scenarios (A2 and B2) at two time periods in the EPIC agro-ecosystem simulation model. The applied climate change scenarios are from the HadCM3 global climate model for the periods 2015–2045 and 2070–2099 which projects consistent increases in temperature and precipitation of greater than 5 8C and up to 300 mm by 2099. An increase in the variability of temperature is also projected and is, accordingly, applied in the simulations. The EPIC model indicates that winter wheat yields would increase on average by 0.2 Mg ha � 1 in the earlier period and by 0.8 Mg ha � 1 in the later period due to warmer nighttime temperatures and higher precipitation. Simulated yields were not significantly affected by imposed changes in crop management. Simulated soil organic C content was higher under both NT management and double cropping than under CT continuous wheat. The simulated changes in management were a more important factor in SOC changes than the scenario of climate change. Soil C sequestration rates for continuous wheat systems were increased by an average of 0.4 Mg ha � 1 year � 1 by NT in the earlier period and by 0.2 Mg ha � 1 year � 1 in the later period. With wheat–corn double cropping, NT increased sequestration rates by 0.8 and 0.4 Mg ha � 1 year � 1 for the earlier and later periods, respectively. The total C offset due to a shift from CT to NT under continuous wheat over 16 million hectares in the Huang-Hai Plain is projected to reach 240 Tg C in the earlier period and 180 Tg C in the later period. Corresponding C offsets for wheat–corn cropping are 675–495 Tg C. # 2005 Elsevier B.V. All rights reserved.

Migration dates at Eyre Bird Observatory: links with climate change?

In contrast to the Northern Hemisphere, relatively little is known about the influence of climate, in particular climate change, on the timing of bird migration in Australia. This paper exam- ines a new dataset, comprising daily abundance records for 8 landbird species at Eyre Bird Observa- tory (EBO), Western Australia, for the period 1984 to 2003. Five of the 8 species were present at Eyre for only part of the year, while the 3 species present all year round exhibited seasonal changes in abundance. For most species, changes in migration dates were related to observed changes in the regional climate; 3 species showed no trend in migration timing, and these had no regular period of absence from EBO. Of the remaining species, the Purple-crowned Lorikeet Glossopsitta porphyro- cephala and Grey Fantail Rhipidura fuliginosa showed strong trends in arrival dates: both winter visitors arrived suddenly at EBO and earlier over time, with lorikeets arriving earlier in years of warmer night-time temperatures. Two species, Fork-tailed Swift Apus pacificus and Rainbow Bee- eater Merops ornatus, had strong trends in departure dates and were summer visitors. These species responded differently to warming night-time temperatures, perhaps reflecting their breeding char- acteristics. The Budgerigar Melopsittacus undulatus arrived and departed suddenly and showed no trend in migration timing, though wetter years corresponded to earlier arrivals. Consistent with global trends, this region warmed, particularly in minimum temperatures (0.05°C yr -1 ). There was no

Combined effects of night-time temperature and allelochemicals on performance of a Solanaceae specialist herbivore

:To assess the influence of temperature on the impact of allelochemicals on the growth of insect herbivores, we examined the interactions between allelochemicals and warmer night-time temperatures on an insect herbivore, Manduca sexta (L.) and tomato plants. We compared the effects of four thermal regimes with a standard day-time temperature of 26°C and the night-time temperature varying from 14 to 26°C by increments of 4°C. Increasing concentrations of chlorogenic acid and tomatine reduced developmental rate linearly. At 26:22°C, there was also a quadratic effect, such that intermediate concentrations had a disproportionately large negative effect. Furthermore, the negative effects of the allelochemicals were less at the 26:14°C regime. These results differ from another study examining a different insect species, which suggests that the response to incremental changes in night-time temperature will vary with the allelochemicals and insect species tested. However, some consistent patterns for M. sexta have emerged. The negative effects on caterpillar development of increasing allelochemical concentration changed across the gradient in night-time temperatures. At one thermal regime (26:22°C), M. sexta growth was disproportionately reduced by intermediate concentrations of each of three allelochemicals tested.