scholarly journals Climate change reduces reproductive success of an Arctic herbivore through trophic mismatch

2007 ◽  
Vol 363 (1501) ◽  
pp. 2367-2373 ◽  
Author(s):  
Eric Post ◽  
Mads C Forchhammer

In highly seasonal environments, offspring production by vertebrates is timed to coincide with the annual peak of resource availability. For herbivores, this resource peak is represented by the annual onset and progression of the plant growth season. As plant phenology advances in response to climatic warming, there is potential for development of a mismatch between the peak of resource demands by reproducing herbivores and the peak of resource availability. For migratory herbivores, such as caribou, development of a trophic mismatch is particularly likely because the timing of their seasonal migration to summer ranges, where calves are born, is cued by changes in day length, while onset of the plant-growing season on the same ranges is cued by local temperatures. Using data collected since 1993 on timing of calving by caribou and timing of plant growth in West Greenland, we document the consequences for reproductive success of a developing trophic mismatch between caribou and their forage plants. As mean spring temperatures at our study site have risen by more than 4°C, caribou have not kept pace with advancement of the plant-growing season on their calving range. As a consequence, offspring mortality has risen and offspring production has dropped fourfold.

Author(s):  
Anke Kloock ◽  
Lena Peters ◽  
Charlotte Rafaluk-Mohr

In most animals, female investment in offspring production is greater than for males. Lifetime reproductive success (LRS) is predicted to be optimized in females through extended lifespans to maximize reproductive events by increased investment in immunity. Males, however, maximize lifetime reproductive success by obtaining as many matings as possible. In populations consisting of mainly hermaphrodites, optimization of reproductive success may be primarily influenced by gamete and resource availability. Microbe-mediated protection (MMP) is known to affect both immunity and reproduction, but whether sex influences the response to MMP remains to be explored. Here, we investigated the sex-specific differences in survival, behavior, and timing of offspring production between feminized hermaphrodite (female) and male Caenorhabditis elegans following pathogenic infection with Staphylococcus aureus with or without MMP by Enterococcus faecalis. Overall, female survival decreased with increased mating. With MMP, females increased investment into offspring production, while males displayed higher behavioral activity. MMP was furthermore able to dampen costs that females experience due to mating with males. These results demonstrate that strategies employed under pathogen infection with and without MMP are sex dependent.


2012 ◽  
Vol 90 (6) ◽  
pp. 736-743 ◽  
Author(s):  
Philip H. Jones ◽  
Jeffrey L. Van Zant ◽  
F. Stephen Dobson

The imbalanced reproductive success of polygynous mammals results in sexual selection on male traits like body size. Males and females might have more balanced reproductive success under polygynandry, where both sexes mate multiply. Using 4 years of microsatellite DNA analyses of paternity and known maternity, we investigated variation in reproductive success of Columbian ground squirrels, Urocitellus columbianus (Ord, 1815); a species with multiple mating by both sexes and multiple paternity of litters. We asked whether male reproductive success was more variable than that of females under this mating system. The overall percentage of confirmed paternity was 61.4% of 339 offspring. The mean rate of multiple paternity in litters with known fathers was 72.4% (n = 29 litters). Estimated mean reproductive success of males (10.27 offspring) was about thrice that of females (3.11 offspring). Even after this difference was taken into account statistically, males were about three times as variable in reproductive success as females (coefficients of variation = 77.84% and 26.74%, respectively). The Bateman gradient (regression slope of offspring production on number of successful mates) was significantly greater for males (βM = 1.44) than females (βF = 0.28). Thus, under a polygynandrous mating system, males exhibited greater variation in reproductive success than females.


2019 ◽  
Vol 66 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Amélie Paoli ◽  
Robert B Weladji ◽  
Øystein Holand ◽  
Jouko Kumpula

Abstract A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species’ reproductive success to decrease. The match–mismatch hypothesis (MMH) is an appealing concept that can be used to assess such fitness consequences. However, concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies. Using a long-term dataset of reindeer calving dates recorded since 1970 in a semidomesticated reindeer population in Finnish Lapland and proxies of plant phenology; we tested the main hypothesis that the time lag between calving date and the plant phenology in autumn when females store nutrient reserves to finance reproduction would lead to consequences on reproductive success, as the time lag with spring conditions would. As predicted, the reproductive success of females of the Kutuharju reindeer population was affected by both the onset of spring green-up and vegetative senescence in autumn as calves were born heavier and with a higher first-summer survival when the onset of the vegetation growth was earlier and the end of the thermal growing season the previous year was earlier as well. Our results demonstrated that longer plant growing seasons might be detrimental to reindeer’s reproductive success if a later end is accompanied by a reduced abundance of mushrooms.


1969 ◽  
Vol 5 (3) ◽  
pp. 195-207 ◽  
Author(s):  
A. H. El Nadi

SummaryExperiments were made in glasshouses, growth cabinets and growth rooms to study the differential responses of the broad bean to water stress during the vegetative and flowering phases of growth. Plants in the flowering phase proved to be more sensitive to drought than in the vegetative period, and there were different responses (Relative Growth Rate) to temperature at different stages of plant growth. Day length and temperature influenced the position of the earliest flower initials on the stem, and intensity of flower shedding was aggravated by high temperature.


1992 ◽  
Vol 72 (1) ◽  
pp. 275-287 ◽  
Author(s):  
N. Richard Knowles ◽  
Gabor I. Botar

The efficacy of utilizing "controlled seed-tuber aging" as a technique to enhance yield and improve tuber quality in areas with relatively short growing seasons was investigated in a 3-yr study. Prior to planting in the field, five physiological ages of Russet Burbank, Carlton, Norchip and Superior seed-tubers were produced by varying the heat-unit accumulation over a 200-d storage interval. Total yield increases of up to 90% and substantial improvements in tuber grade were achieved by planting aged (600–900 degree-day (dd)) seed-tubers. Plant growth from aged Russet Burbank seed-tubers was modelled to identify the mechanisms by which yield and quality were altered. Growth analysis demonstrated that the age-induced yield increases were due to faster emergence, faster leaf-area establishment, and tuberization earlier in the growing season compared with that from younger seed-tubers. The annual life cycle was thus accelerated, allowing plants from older seed-tubers to utilize the short (120-d) growing season more efficiently than those from younger seed-tubers. This was reflected in a higher harvest index: plants from 739 dd seed-tubers partitioned 63% of their total fresh weight into tubers compared with 48% for those from 66 dd seed-tubers (based on the quadratic model describing the relationship between seed-tuber age and and harvest index at 121 d after planting). The technique appears to be very promising for enhancing yield and/or promoting ’earliness’ of potatoes in regions with short growing seasons.Key words: Solanum tuberosum, seed-tuber age, plant growth, yield


2012 ◽  
Vol 49 (2) ◽  
pp. 225-233
Author(s):  
Pantelitsa Kapagianni ◽  
Nikos Monokrousos ◽  
George P. Stamou ◽  
Efimia Papatheodorou

2006 ◽  
Vol 274 (1607) ◽  
pp. 281-286 ◽  
Author(s):  
Annaliese K Beery ◽  
Justin J Trumbull ◽  
Jyeming M Tsao ◽  
Ruth M Costantini ◽  
Irving Zucker

Day length is the primary cue used by many mammals to restrict reproduction to favourable spring and summer months, but it is unknown for any mammal whether the seasonal loss of fertility begins at the same time and occurs at the same rate in females and males; nor it established whether the termination of mating behaviour in males and females coincides with the loss of fertility. We speculated that females, owing to their greater energetic investment in reproduction, are the limiting sex in terminating offspring production in short days (SDs). Oestrous cycles and production of young were monitored in Syrian hamsters ( Mesocricetus auratus ) transferred from long days (LDs) to SDs. Females were mated to LD males after three to eight weeks of SD treatment; in a parallel experiment, males housed in SDs were mated to LD females. After five and eight weeks in SDs, at least twice as many males as females were fertile. Both males and females continued to copulate for several weeks after becoming infertile. The onset of seasonal infertility occurs earlier in females than males and the decline in fertility precedes the seasonal loss of mating behaviour in both sexes.


1988 ◽  
Vol 6 (3) ◽  
pp. 101-104
Author(s):  
Julie A. Jacobson ◽  
James E. Klett

Six different preemergence herbicides including one herbicide combination were applied to container-grown Dianthus barbatus L. (Sweet William) and evaluated for their effects on weed control, plant growth and phytotoxicity. Napropamide (Devrinol 10G), oryzalin (Surflan 40.4% AS), oxyfluorfen + oryzalin (Rout GS-3G), oxadiazon (Ronstar 2G), metolachlor (Dual 8EC), simazine (Princep 4G) and Dual and Princep were applied to container-grown Sweet William and studied for a growing season. Weed seeds sown were yellow foxtail, annual bluegrass, common groundsel, common chickweed, and creeping woodsorrel. Devrinol, Surflan, and Rout GS resulted in the best weed control without affecting the overall growth of Sweet Wiliam or resulting in any phytotoxicity at rates applied. Dual and Princep resulted in phytotoxicity at all rates applied on Sweet William to a degree that would make the plants unsalable.


2020 ◽  
Author(s):  
Tyson Wepprich ◽  
Fritzi S Grevstad

Abstract A key knowledge gap in classical biological control is to what extent insect agents evolve to novel environments. The introduction of biological control agents to new photoperiod regimes and climates may disrupt the coordination of diapause timing that evolved to the growing season length in the native range. We tested whether populations of Galerucella calmariensis L. have evolved in response to the potential mismatch of their diapause timing since their intentional introduction to the United States from Germany in the 1990s. Populations collected from 39.4° to 48.8° latitude in the western United States were reared in growth chambers to isolate the effects of photoperiod on diapause induction and development time. For all populations, shorter day lengths increased the proportion of beetles that entered diapause instead of reproducing. The critical photoperiods, or the day length at which half of a population diapauses, differed significantly among the sampled populations, generally decreasing at lower latitudes. The latitudinal trend reflects changes in growing season length, which determines the number of generations possible, and in local day lengths, at the time when beetles are sensitive to this cue. Development times were similar across populations, with one exception, and did not vary with photoperiod. These results show that there was sufficient genetic variation from the two German source populations to evolve different photoperiod responses across a range of environmental conditions. This study adds to the examples of rapid evolution of seasonal adaptations in introduced insects.


2010 ◽  
Vol 4 (1) ◽  
pp. 17-22
Author(s):  
C. Wesley Wood ◽  
Maribeth C. Duqueza ◽  
Brenda H. Wood

Long-term land application of manure, litter, and dead-bird compost generated during poultry (Gallus, gallus) production may oversupply nitrogen (N) and result in nitrate (NO3-N) contamination of groundwater. A barrier to judicious use of poultry waste as a fertilizer is the absence of management tools for prediction of waste-derived N released during the plant growing season. This study was conducted to establish an N extraction method for poultry wastes as a predictor of soil N release owing to land application of poultry waste. We correlated N released from 87 different poultry wastes in a 60-day incubation with seven bioavailability predictors. Bioavailability predictors included autoclave-calcium chloride (CaCl2) extraction, bicarbonate extraction, Walkley-Black (acid dichromate) digestion, acid permanganate digestion, pepsin digestion, protein extraction, and barium hydroxide extractable glucose. Results indicate that acid permanganate digestion (r=0.77) has the highest potential for predicting N mineralized from poultry wastes followed by sodium bicarbonate extraction (r=0.51). However, the relationships are not strong enough to indicate that these methods would be useful in a practical, predictive sense.


Sign in / Sign up

Export Citation Format

Share Document