The role of linear mown firebreaks in conserving butterfly diversity: Effects of adjacent vegetation and management

Semi‐natural grasslands are vital for maintaining grassland butterflies in Japan, as well as in Europe. However, severe decline in these grassland environments has recently attracted attention to linear grasslands, such as firebreaks and power‐line corridors, as alternative habitats for grassland insects. We surveyed butterflies in an abandoned grassland and nearby linear mown firebreaks adjacent to different vegetation at the northern foot of Mt. Fuji, central Japan, over 5 successive years, particularly focusing on species on the 2012 Japanese Red List of Threatened Species (“red‐list” species). We found that the firebreaks were consistently higher in species richness and abundance of butterflies than the long‐term abandoned grassland, and that species composition differed among the firebreaks depending on conditions of the adjacent vegetation. The firebreaks surrounded by forests were mainly utilized by forest and edge species, whereas the firebreaks adjacent to the grassland were essential for conserving red‐list grassland species. Thus, only the mown firebreaks adjacent to the grassland were regarded as a high‐quality alternative habitat for many grassland butterflies, but the area was limited. Therefore, creating heterogeneity in the abandoned grassland by infrequent mowing could help conserve grassland butterflies, including red‐list species.     

Low heritability in morphological characters of Tengmalm's owls: The role of cyclic food and laying date?

Summary In parent—offspring regressions, high heritability estimates of characters may simply be due to common environment: the resemblance between the living conditions of parents and their offspring in species showing restricted natal dispersal. In vole-eating Tengmalm's owls (Aegolius funereus), the natal dispersal and breeding dispersal of adult females are wide (up to > 1000 km and > 500 km, respectively), whereas adult males are resident. We found that body measurements of 183 recruits born in western Finland were independent of parental age and vole abundance in the birth year. Early-laid eggs produced longer winged recruits than late-laid eggs. The wing lengths of the daughters showed a significant positive regression on the wing length of their mothers, but the removal of the maternal effect via laying date lowered this relationship. The development time of offspring to the first autumn might also be crucial for morphological characters of females in their later life. Significant regressions were not found between the wing length of the son and his father. The mother—daughter regression was small for laying date, but positive (p = 0.08) for clutch size. These results suggest low heritability in breeding and morphological characters of owls and this low heritability may enable plastic adjustment to optimize fitness at any stage in a fluctuating environment. Nonadditive genetic variance also creates variation between offspring characters that are not genetically correlated with the parents and may explain these low heritability estimates.     

Short-Term Temporal Effects on Community Structure of Lepidoptera in Restored and Remnant Tallgrass Prairies

Understanding the degree to which species assemblages naturally vary over time will be critically important when assessing whether direct management effects or contingency is responsible for species gain or loss. In this study, we tested three predictions related to short‐term variation in prairie moth communities: (1) communities would only exhibit significant temporal variation in newly restored sites (1–3 years old); (2) prairie size and age would positively influence community reassembly, with larger, older restorations sampling a greater proportion of the regional species pool; and (3) older restorations (7–10 years old) would have yet to converge on the community composition of prairie remnants. Moths were sampled from 13 Tallgrass prairie restorations and remnants in central Iowa in 2004–2005. Repeated measures analysis of variance revealed significant effects of sampling year on moth species richness and abundance as well as on the richness of two functional groups, but difference among prairie types was only observed in 2005. Rarefaction analysis revealed that older restorations and prairie remnants supported higher species richness compared to recently planted sites, and nonmetric, multidimensional scaling ordination indicated that restorations older than 7 years were clearly converging on the species composition of remnants. These results suggest that moth communities in restorations and remnants are highly variable in time but that as restorations age, they appear to reaccumulate moth species found in prairie remnants. The long‐term persistence of a particular species assemblage within a given site, however, might be a difficult endpoint to attain in central Iowa prairies because of significant annual variation in species occurrence.     

Interannual variation in precipitation and other planting conditions impacts seedling establishment in sown plant communities

Ecological restoration can reverse biodiversity loss worldwide, yet restoration goals and outcomes vary widely, which limits this potential. Divergent restoration outcomes may stem from variation in conditions at the outset of restoration, but empirical evidence is lacking and typically confounded with site differences. Additionally, precipitation is usually cited as the source of this variation, although a wide range of conditions can vary annually. We tested for effects of planting year on seedling establishment by installing identical restorations in three different years. Within those years, we manipulated rainfall with rain‐out shelters to disentangle the effects of precipitation from other annually variable conditions. Additionally, we tested whether increasing seed mix richness buffers against adverse planting conditions. For the first growing season after planting, we followed emergence and survival of sown prairie species and nonsown weed species to determine how planting year conditions influence an establishing plant community, if at all. We found that seedling establishment differed across planting years and precipitation treatments, and that varying emergence patterns by species led to differences in the composition of the first‐year community. We also found significant variation in sown species establishment across years when precipitation was held constant, illustrating the previously overlooked role of nonprecipitation drivers on planting year effects. Higher seed mix richness did not consistently improve establishment of sown species under different planting conditions. This research provides important experimental evidence for effects of interannual variation in planting conditions on first‐year establishment. Future work will examine how these initial changes affect longer‐term assembly dynamics.     

Effect of initial size on daily growth and survival in freshwater Chondrostoma nasus larvae: a field survey

Effects of initial size on the growth and survival of a freshwater fish, Chondrostoma nasus , were tested in a field survey, where individually tagged larvae were introduced into a potential nursery habitat. Characteristics of individual daily growth trajectories were utilized as a basis to explain growth, as well as survival patterns, in relation to ontogeny. Initial size only affected growth rates during the larval phase. Survival patterns could not be explained solely based on size-selective mortality processes because prey–predator interactions played a major role as well. This is confirmed by the Lande–Arnold selection model because directional, as well as stabilizing gradients, showed significant values. Thus, for the 0+ year freshwater fish, inherited size-specific effects were a significant advantage for growth performance and survival in early ontogeny. As fish grew older, however, other effects such as compensatory growth and prey–predator interactions apparently gained in importance.     

用耗散结构理论对莫高窟园林用水的分析

通过莫高窟园林用水的调查,发现平均灌溉量为8366mm,远高于敦煌农田的灌水量2250mm,并且全部通过土壤表面蒸发和植物蒸腾耗散掉了.这就出现了一个实际用水量很高的地方,它仍然表现为缺水的悖逆现象.而且也远大于以水面为基础当地的耗散量2486mm.应用 Penman的蒸散指数、Thornthwaite的蒸散指数、Holdridge生命地带指标等进行比较研究,结果仍然不能解释莫高窟存在的现象.通过对于莫高窟的温度、光照、湿度、风速、热量、土壤结构、浇灌方式等与水分耗散有关的因子进行深入的调查与分析后,发现这个现象与耗散结构理论相吻合.应用耗散结构理论解释了在莫高窟园林用水中存在的一个似非而是的问题.水的耗散结构理论对西北干旱地区的水资源利用有重要意义.应用耗散结构理论与前人对水分耗散方面的研究并不矛盾,完全可以在这一理论指导下统一起来,有望建立起统一的水分耗散应用模型.同时对与耗散结构理论相关的熵问题进行了探讨,认为这个问题与时间问题一样,是认识的主体——人的心理错觉,并没有物质上的实质.     

Contingent Conclusions: Year of Initiation Influences Ecological Field Experiments,but Temporal Replication is Rare

Interannual variation in experimental field conditions produce variability in the results of experiments monitored over multiple years, termed here “year effects.” When experimental treatments are replicated in separate years, interannual variation may influence treatment effects and produce significant treatment by initiation‐year interactions. Understanding the frequency and strength of these effects requires initiating identical experiments across years. We conducted a review of literature covering more than 500 experimental articles published in 7 journals between 1966 and 2008. Only 5% of the 276 general ecological field studies initiated experiments in multiple years. This rarity was even more evident in the journal Restoration Ecology, in which none of the 173 surveyed experimental studies initiated experiments in multiple years. In contrast, 48% of the 58 field experiments published in an agronomy journal were replicated across years. We found only 17 studies that tested treatment by initiation‐year interactions. Despite their rarity, 76% of these studies found significant interactions between treatment and initiation year. We conclude that the results of many ecological field experiments are likely to be contingent on the year in which they are implemented. We discuss the importance of treatment by initiation‐year interactions in ecology and restoration, factors that have hindered the inclusion of temporal replication in the past, and some suggestions for the appropriate design and analysis of temporally replicated experiments. We argue for more deliberate investigation of temporal contingency in ecological experimentation, especially in the field of restoration ecology, which may be particularly sensitive to treatment by initiation‐year interactions.     

Consequences of the inscription of local breeds in protected designation of origin cow cheese specifications for the genetic management of the herds

In the mountainous areas of Europe with a humid climate, dairy cattle production is a major agricultural activity, and the milk is often processed into cheese according to protected designation of origin (PDO) specifications. We analyzed the extent to which PDO specifications and/or a mountain environment influence the spatial distribution of estimated breeding values (EBVs) of cows and the herd-year effects (HYEs) for milk yield (kg/lactation) and protein and fat contents (g/kg), as well as lactation ranks and calving months. The study focused on the northern French Alps. A total of 37 023 lactations, recorded in 2006, in 1153 herds were analyzed. The cows belonged to the Montbéliarde (21 516 lactations), Abondance (10 346 lactations) and Tarentaise (5161 lactations) breeds. The two factors of variation considered were the status of the commune where the farm was located in relation to PDO (three categories: area with no PDO, area with a PDO with no milk yield limit, area with a PDO with a milk yield limit) and 'mountain' environment (four categories based on the European regulation: plain, piedmont, mountain and high mountain). In the Abondance breed, the average lactation rank increased with an increase in production constraints due to the PDO or to a mountain environment. In the Abondance and Tarentaise breeds, grouping of calving in winter was most marked in the 'PDO with a milk yield limit' and 'high-mountain' categories. In the Tarentaise breed, no significant effect on any trait and any variable was found in the 'PDO' or 'mountain' categories. In the other two breeds, the average EBV for milk yield decreased with an increase in the constraints due to PDO, with differences of 226 and 93 kg between extreme values in the Abondance and Montbéliarde breeds, respectively. The average HYE for milk yield was higher in the Abondance breed in the 'PDO with no milk yield limit' category than in the other categories (+740 and +1110 kg, respectively); HYE was not affected by the 'PDO' factor in the Montbéliarde breed or by the 'mountain' factor in either breed. Concerning the protein and fat contents, the effect of the 'PDO' and 'mountain' factors depended on the trait, the variable and the breed. The proportion of individual decisions (the farmer makes the decision) v. collective decisions (breed management) concerning herd dynamics in the face of existing constraints is discussed.     

Variations in the spawning periodicity of eight fish species in three English lowland rivers over a 6 year period, inferred from 0+ year fish length distributions

The spawning periodicity of eight fish species was investigated in three English lowland rivers over a 6 year period from patterns in 0+ year fish standard length ( L _S) distributions. A single cohort of 0+ year dace Leuciscus leuciscus , roach Rutilus rutilus and perch Perca fluviatilis was observed each year, suggesting that these species spawned only once annually. By contrast, populations of chub Leuciscus cephalus , bleak Alburnus alburnus , bream Abramis brama , gudgeon Gobio gobio and minnow Phoxinus phoxinus were inferred to spawn on more than one occasion each year. Annual and intercatchment variations occurred in the L _S distribution patterns of some of the fish species. In chub, for example, although a minimum of two 0+ year cohorts occurred in all years in the River Trent, 'multiple' spawning (either at the individual or population level) was most apparent in 1999, 2003 and 2004. By contrast, 'multiple' spawning events were not evident in all years in the Warwickshire Avon and Yorkshire Ouse, with recruitment presumably based upon a single spawning event in some years. There is effectively a trade-off between early spawning (extended growing season), and the possibility that environmental conditions will impact upon recruitment success, and the potential for reduced overwinter survival of smaller individuals with lower lipid resources from later spawning events. Notwithstanding, fishes as small as 15 mm L _S survived the winter in some years, suggesting that progeny from later spawning events may make important contributions to fish recruitment success.