Miracle-dz/UniFAR-FTUs huggingface dataset:
THE EFFECT OF HABITAT CORRIDORS ON RATES OF TRANSFER AND INTERBREEDING BETWEEN VOLE DEMES

It has been proposed that habitat corridors enhance exchange of individuals (transfer) and interbreeding between otherwise isolated demes in fragmented populations. However, due to the paucity of experimental studies this proposition has become contro- versial. We tested these proposed effects of corridors in 12 experimentally fragmented root vole populations. A 50-m long habitat corridor connected two large habitat patches in each of six treatment populations, while equivalent habitat patches in six control populations had no corridor connection. Each of the two patches in each population was initially colonized by founder demes that were monomorphic with respect to two different marker alleles of a single locus. The rate of transfer of individuals and the resultant degree of interbreeding (heterozygosity) between the two demes were monitored by capture-recapture methodology and genetic analyses over the reproductive season. Females were predominantly philopatric in these populations; more than four-fifths of the founder deme females settled and reproduced in their original patch. However, corridors significantly facilitated the transfer of females. The transfer rate of males was generally very high; approximately four-fifths, independent of the experimental factor (absence or presence of corridors). The sex-specific transfer pattern gave rise to very high rates of interbreeding (heterozygosity). The rate of interbreeding was enhanced by the presence of corridors, and more so than expected from the transfer rate. The lack of concordance between expected and observed heterozygosity in the corridor populations was probably due to short-term mating excursions facilitated by the presence of corridors.
Differential Herbicide Response among Three Phenotypes of Cabomba caroliniana

Abstract Cabomba is a submersed aquatic plant native to the southeastern United States that is commonly sold worldwide through the aquarium trade. While infrequently managed in its native range, cabomba has recently been reported as invasive and tolerant to management efforts in the northern areas of the United States and in other countries. Invasive populations of cabomba are characterized by a phenotype that is bright green. In contrast, cabomba native to the southeastern United States is characterized by a red phenotype, while plants sold through the aquarium trade have intermediate characteristics of both the green and red phenotypes. The response of the three cabomba phenotypes to selected herbicides was evaluated by measuring photosynthetic response over the course of a static 144-hr exposure. Plants were exposed to the maximum recommended use-rates of 2,4-D, carfentrazone, copper, diquat, endothall (amine and dipotasium salt formulation), flumioxazin, quinclorac, triclopyr, and a combination of diquat and copper. A submersed plant species known to be sensitive to each of these herbicides was also included to compare photosynthetic response of the cabomba to a susceptible plant. The photosynthetic response of the red and green phenotypes differed following exposure to carfentrazone, diquat, 2,4-D, triclopyr, and flumioxazin. Diquat, diquat plus copper, endothall (amine salt), and flumioxazin were the only products that resulted in a greater than 50% reduction of photosynthesis in all three phenotypes of cabomba. A second experiment was conducted where all three phenotypes of cabomba were exposed to these four herbicides for 24 hr, and photosynthesis was evaluated. Following the 24-hr exposure, results further documented distinct response differences between the green and red phenotypes, with the green phenotype demonstrating a reduced sensitivity to the herbicides evaluated. Results demonstrate clear phenotypic differences in response to herbicide treatments and lack of susceptibility of cabomba to most herbicides. Nomenclature: Carfentrazone; copper; 2,4-D; diquat; endothall; flumioxazin; triclopyr; quinclorac; Cabomba, Cabomba caroliniana Gray CABCA.
Empirical analysis of zooplankton filtering and feeding rates1

Multiple regression analysis of published zooplankton filtering and feeding rates yielded separate regression equations for cladocerans, marine Calanoid copepods, and all zooplankton. Ingestion rate was found to increase significantly with animal size, food concentration, and temperature. Filtering rate also increased with animal size and temperature, but declined as food concentration increased. The analysis suggests a difference in particle size preference between cladocerans and copepods. Experimental conditions such as crowding and duration also significantly affected filtering and feeding rates. The regression models allow examination of differences and similarities among zooplankton taxa, functional response, particle size selection, energy allocation, and threshold food concentration. The statistical models describe suspension feeding more precisely than either average literature values or verbal descriptions of trend. The results also suggest possible mechanisms of feeding limitation and provide a heuristic framework for the design of experimental analyses of zooplankton feeding in marine and freshwater systems.
MODELING PATCH OCCUPANCY BY FOREST RODENTS: INCORPORATING DETECTABILITY AND SPATIAL AUTOCORRELATION WITH HIERARCHICALLY STRUCTURED DATA

Abstract Widespread conversion of deciduous forests to agriculture in the midwestern United States has resulted in landscapes whose remaining native habitats are highly fragmented, with well-documented consequences for wildlife community structure. We analyzed trap data for 5 forest rodent species from 525 sites in 35 study landscapes throughout the upper Wabash River basin, which is dominated by agricultural use and drains >20% of Indiana. We used a recently developed likelihood approach and multi-model inference to obtain unbiased estimates of occurrence probabilities for a species when detection rates are <1, and we used hierarchical generalized linear modeling to evaluate random effects associated with nested data structure. Inclusion of a spatial autocovariate term had important effects on model selection results for 4 of 5 species and improved fit of models. Eastern chipmunks (Tamias striatus), although previously described as sensitive to fragmentation, were nearly ubiquitous in our study region and had greater occupancy rates in smaller woodlots. Fox squirrels (Sciurus niger) are well adapted to patchy landscapes, and their occupancy rates actually increased with patch isolation. Gray squirrels (S. carolinensis) are adversely affected by forest fragmentation; we observed a threshold decline in occupancy rates beyond ∼15 km from the Wabash River, which harbors the only source of contiguous habitat within the entire river basin. Red squirrels (Tamiasciurus hudsonicus) exhibited greater abundance in sites without gray squirrels. Moreover, their occupancy rates were positively related to habitat and landscapes considered suboptimal (e.g., lower basal area of hard-mast bearing trees, more isolated patches); this was further evidence for negative effects of gray squirrels on red squirrel populations. White-footed mice (Peromyscus leucopus) were nearly ubiquitous; although occurrence rates in less forested landscapes increased with distance from edge and greater volume of woody debris.
Zugunruhe of migratory and non-migratory birds in a circannual context

Recent findings in non-migratory birds have reopened questions about the interpretation and seasonal organization of Zugunruhe. I address the relationship between Zugunruhe and migration by comparing underlying circannual patterns in captive populations of migratory and non-migratory stonechats. Zugunruhe was highly variable and lacked clear periodicity, indicating its sensitivity to external cues. Patterns of Zugunruhe were similar in African residents, European short-distance migrants, and Siberian long-distance migrants, revealing no major difference in circannual organization. Moult was regulated independently of Zugunruhe and timed more rigidly, particularly in stonechats from equatorial Africa. The persistent and variable circannual patterns of Zugunruhe suggest that non-migratory and migratory stonechats have similar underlying programs but have modified the expression of actual migration. The findings, together with published observations from other species, emphasize the importance of considering programs for migration in a wide range of species, without losing sight of its environmental context.
Sucrose and Cytokinin Interactions in Relation to Ethylene and Abscisic Acid Production in the Regulation of Morphogenesis in Pelargonium × hortorum L.H. Bailey In Vitro

The aim of the study was to determine the effect of exogenous sucrose and cytokinin on ethylene production and responsiveness in relation to the shoot formation of Pelargonium × hortorum 'Bergpalais' in vitro. Increasing the concentration of sucrose from 15 to 40 g L-1 in medium containing meta-topolin (mT) resulted in a two-fold decrease in the number of shoots and leaves as well as a reduction in ethylene production. The addition of ethylene synthesis inhibitor (AVG) to mT-medium significantly reduced the ethylene production and the shoot growth, but it had no significant influence on the shoot formation. The mT-induced shoot formation was, however, significantly reduced in the presence of ethylene action inhibitor (AgNO3), in a manner dependent on sucrose levels. At the end of the subculture period, increased sucrose concentrations (15–40 g L-1) in the presence of mT and AgNO3 resulted in a 3.7-fold increase in ethylene emission. At the same time, the supply of sucrose caused a 2.8-fold increase in the level of endogenous abscisic acid (ABA). Our results may suggest that the inhibitory effect of high sucrose concentration (30 and 40 g L-1) may depend on its influence on ethylene sensitivity. It also suggests that sucrose-regulation of the shoot formation of Pelargonium in vitro is mediated by ABA.
Null model analysis of community structure reveals that patch quality influences the conservation of complex bird communities in Mediterranean habitats

The bird communities of the Presidential Estate of Castelporziano (Rome, Italy) were studied to determine their structure in a set of different natural habitats. This study area presents a complex ecosystem, formed by a mosaic of different habitats and their ecotones, having a high biodiversity level. Wetlands housed the highest number of bird species followed by oak forests. Bird communities of Castelporziano are characterized by high degrees of richness and complexity. Null model analyses revealed that the bird community was not randomly organized by Randomization Algorithm 2 (thus denoting that the generalist-specialist nature of the species reduced ecological similarity) nor by Randomization Algorithm 3 and Randomization Algorithm 4 (thus denoting that the types of resources utilized did not reduce ecological similarity). Based on this study, we will not only focus on conservation levels of single habitats for Mediterranean birds, but also modify the classical approach of ‘fragmentation biology’ with a new approach where the natural quality of all patches is evaluated with appropriate statistical tools
Habitat and population estimates of some threatened lowland forest bird species in Tambopata, south-east Peru

Surveys of threatened lowland forest bird species and forest habitats were conducted during a 21-month census of lowland bird communities in Tambopata, Department of Madre de Dios, south-east Peru. A combination of distance sampling census methods and direct counts was used for the census in five sites located along the Rio Madre de Dios and Rio Tambopata. All five sites consisted of different forest types with significantly different habitat components. Three of these sites were classified as primary forest habitats whilst the remaining two were classified as disturbed forests. Population densities were calculated for eight of the threatened species recorded during the census. Density estimates of non-bamboo specialists were higher in primary forest habitats than in disturbed forest habitats. Density estimates of most bamboo specialists were higher in primary Old Floodplain forest with extensive bamboo understorey than in primary Middle/Upper Floodplain forest with smaller, patchy areas of bamboo understorey. Calculation of regional population estimates based on the amount of forest cover from satellite photographs shows that only two of the threatened bird species have substantial populations currently protected by the Parque Nacional Bahuaja-Sonene and Reservada Nacional de Tambopata. Selective logging operations that reduce overall tree biomass and remove a large proportion of palm tree species from primary forest habitats will have an adverse affect on local populations of four of the threatened bird species in the region.
Do Variations in Local Leaf Irradiance Explain Changes to Leaf Nitrogen within Row Maize Canopies

Abstract Numerous studies have dealt with the relationship between leaf nitrogen content and leaf irradiance. However, most of them refer to dense stands presenting reduced horizontal heterogeneity of foliage distribution. Both gradients of leaf nitrogen and leaf irradiance related to canopy depth are significant under such conditions, and modelling radiative exchange using a turbid-medium analogy and dividing the canopy into vegetation layers is sufficient. Conversely, row crops such as maize are characterized by strong horizontal heterogeneity of foliage distribution and the one-dimensional (1D) approach may be unsuitable. We thus modelled the three-dimensional (3D) geometry of maize canopies with varying densities and at different developmental stages using plant digitizing under field conditions. The nitrogen content per unit area of each leaf part was obtained subsequently by nitrogen analysis. We next calculated radiative exchange using a 3D volume-based approach within the canopies in order to estimate local leaf irradiance on a daily integration scale. Vertical gradients in leaf nitrogen content per unit area observed in dense stands during the vegetative phase corresponded largely to those reported in the literature. We also identified significant gradients in nitrogen content along the leaves, which had not before been clearly demonstrated. Our study shows that local light climate during plant development plays a major role in leaf nitrogen distribution and remobilization. Moreover, brutal plant thinning involves rapid changes in leaf nitrogen partitioning. It is concluded that taking account of the 3D heterogeneity of nitrogen and irradiance distribution may have implications for modelling crop photosynthesis and production.
EFFECT OF DIRECT-FED MICROBIAL (DFM) ® SUPPLEMENTS ON GENERAL PERFORMANCE OF NEWBORN AWASSI LAMBS

Accelerating the onset of weaning of pre-ruminant can be achieved by enhancing the development of rumen microorganisms using direct fed microbial (DFM). The aim of this study was to investigate the effect of feeding DFM to newborn Awassi lambs on their performance at different weaning ages (30, 45 and 60 days old). Forty eight Awassi lambs divided randomly into six groups where each group assigned to one of the following treatments: control (C) (weaning at 60 days old); T1, 2 doses DFM (weaning at 30 days old); T2, 2 doses DFM (weaning at 45 days old ); T3, 2 doses DFM (weaning at 60 days old); T4, (weaned at 30 days old) and T5, (weaned at 45 days old). Feed intake, body weight, blood samples, carcass weights and tissues samples and weight were taken and recorded. Blood samples and tissues were analyzed for mineral concentrations (Cu, Zn, Fe, Mg, Mn and Co) by using Atomic Absorption Spectrophotometer. A significant higher total weight gain were reported for lambs of T2 (2 doses DFM-45 days weaning age) followed by the control, T1, T3, T4 and T5, respectively, but no significant differences among all groups was noticed in term of total feed conversion. The highest dressing percentage was found for lambs of the control group followed by T1, T2 and T3 and the lowest for lambs from T4 and T5. Furthermore, no significant effect for treatments on all tissues percentages except kidney which showed significantly lower weights for all treated groups compared with the control. The rumen and reticulum weights were higher for all treated groups compared with control except lambs of T3. A significant effect of treatment, time and treatment*time were detected for blood serum metabolites and minerals except for Copper and Iron. Moreover, no significant effect for treatments on mineral concentrations in kidney, liver and meat tissues. In conclusion, using direct fed microbial (DFM) accelerate the early weaning of newborn lambs (30 and 45 days old) by enhancing rumen microorganisms development especially for the 45 days weaning age without any negative effect on their growth and performance compared with weaning at 60 days old.
Methane and soil CO2 production from current‐season photosynthates in a rice paddy exposed to elevated CO2 concentration and soil temperature

Quantification of rhizodeposition (root exudates and root turnover) represents a major challenge for understanding the links between above‐ground assimilation and below‐ground anoxic decomposition of organic carbon in rice paddy ecosystems. Free‐air CO2 enrichment (FACE) fumigating depleted 13CO2 in rice paddy resulted in a smaller 13C/12C ratio in plant‐assimilated carbon, providing a unique measure by which we partitioned the sources of decomposed gases (CO2 and CH4) into current‐season photosynthates (new C) and soil organic matter (old C). In addition, we imposed a soil‐warming treatment nested within the CO2 treatments to assess whether the carbon source was sensitive to warming. Compared with the ambient CO2 treatment, the FACE treatment decreased the 13C/12C ratio not only in the rice‐plant carbon but also in the soil CO2 and CH4. The estimated new C contribution to dissolved CO2 was minor (ca. 20%) at the tillering stage, increased with rice growth and was about 50% from the panicle‐formation stage onwards. For CH4, the contribution of new C was greater than for heterotrophic CO2 production; ca. 40–60% of season‐total CH4 production originated from new C with a tendency toward even larger new C contribution with soil warming, presumably because enhanced root decay provided substrates for greater CH4 production. The results suggest a fast and close coupling between photosynthesis and anoxic decomposition in soil, and further indicate a positive feedback of global warming by enhanced CH4 emission through greater rhizodeposition.
Acoustic seabed classification: current practice and future directions

Anderson, J. T. , Holliday, D. V. , Kloser, R. , Reid, D. G. , and Simard, Y. 2008. Acoustic seabed classification: current practice and future directions. - ICES Journal of Marine Science, 65: 1004-1011.Acoustic remote sensing of the seabed using single-beam echosounders, multibeam echosounders, and sidescan sonars combined and individually are providing technological solutions to marine-habitat mapping initiatives. We believe the science of acoustic seabed classification (ASC) is at its nascence. A comprehensive review of ASC science was undertaken by an international group of scientists under the auspices of ICES. The review was prompted by the growing need to classify and map marine ecosystems across a range of spatial scales in support of ecosystem-based science for ocean management. A review of the theory of sound-scattering from seabeds emphasizes the variety of theoretical models currently in use and the ongoing evolution of our understanding. Acoustic-signal conditioning and data quality assurance before classification using objective, repeatable procedures are important technical considerations where standardization of methods is only just beginning. The issue of temporal and spatial scales is reviewed, with emphasis on matching observational scales to those of the natural world. It is emphasized throughout that the seabed is not static but changes over multiple time-scales as a consequence of natural physical and biological processes. A summary of existing commercial ASC systems provides an introduction to existing capabilities. Verification (ground-truthing) methods are reviewed, emphasizing the difficulties of matching observational scales with acoustic-backscatter data. Survey designs for ASC explore methods that extend beyond traditional oceanographic and fisheries survey techniques. Finally, future directions for acoustic seabed classification science were identified in the key areas requiring immediate attention by the international scientific community.
The influence of oviposition phenology on survival in host races of Eurosta solidaginis

Phenological differences between host plants can contribute to allochronic isolation of host races of phytophagous insects. Host races of the gallmaking fly, Eurosta solidaginis, that live on different species of goldenrod (Solidago altissima and S. gigantea) exhibit different emergence phenologies. These differences could result from adaptation to corresponding phenological differences between the hosts in periods of optimal suitability for gall formation and survival to adulthood. In order to test this, some flies of each host race were allowed to emerge naturally while the emergence times of others were manipulated to correspond to the emergence and oviposition periods of the other host race. Percent gall formation and survival to adulthood were examined for three oviposition periods: the peak time of emergence and oviposition of the earlier‐emerging host race (that from S. gigantea), that of the later‐emerging host race (that from S. altissima), and a week after the peak emergence of the host race from S. altissima. Flies of both host races were allowed to ovipuncture plants of the appropriate species during each of these periods. Plant relative growth rates were measured during each of these periods. The experiment was repeated twice over a two‐year period. Relative growth rates of both host species were highest during the earliest oviposition period (the period during which the host race from S. gigantea normally emerges). Percent gall formation was significantly correlated with plant relative growth rate, but the coefficient of determination was low. In both years of the study, percent gall formation of both host races was highest during the earliest oviposition period (the period during which the host race from S. gigantea normally oviposits). Likewise, percent survival to adulthood in both host races was highest during the earliest oviposition period. There was no significant effect of oviposition period on the percent of larval death due to parasitism by Eurytoma gigantea or predation by Mordellistena unicolor. These results suggest that the host race from S. altissima does not emerge at the time that its host is optimally suited for gall formation or survival to adulthood. Therefore, differences in emergence phenologies do not appear to be due to corresponding phenological differences between the host species in suitability for gall formation or survival to adulthood.