The importance of the encounter rate between ants and herbivores and of ant aggressiveness against herbivores in herbivore exclusion by ants on Vicia angustifolia L. (Leguminosae) with extrafloral nectaries

Abstract—We present a new species, Turnera fasciculifolia, from the Jalapão region, the largest continuous protected area of Cerrado in Tocantins State, in central Brazil. The new species belongs to Turnera series Leiocarpae, and it can be recognized by the linear ericoid leaves with revolute margin, generally without extrafloral nectaries, and the basal leaves of the young axillary branches gathered in fascicles. We provide a description, illustrations, a distribution map, and a comparison with T. genistoides and T. revoluta, which also have ericoid leaves.

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Ant foraging pattern influenced by the variation in the attractiveness of extrafloral nectaries

10.1603/ice.2016.110715 ◽

2016 ◽

Author(s):

Eduardo Calixto Calixto Soares

Keyword(s):

Extrafloral Nectaries ◽

Ant Foraging ◽

Foraging Pattern

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Response of fungal endophyte communities within Andropogon gerardii (Big bluestem) to nutrient addition and herbivore exclusion

Fungal Ecology ◽

10.1016/j.funeco.2021.101043 ◽

2021 ◽

Vol 51 ◽

pp. 101043

Author(s):

Monica Watson ◽

Kathryn Bushley ◽

Eric W. Seabloom ◽

Georgiana May

Keyword(s):

Fungal Endophyte ◽

Andropogon Gerardii ◽

Nutrient Addition ◽

Big Bluestem ◽

Herbivore Exclusion

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Effects of Grazer Exclusion on Carbon Cycling in Created Freshwater Wetlands

Land ◽

10.3390/land10080805 ◽

2021 ◽

Vol 10 (8) ◽

pp. 805

Author(s):

Delanie M. Spangler ◽

Anna Christina Tyler ◽

Carmody K. McCalley

Keyword(s):

Soil Carbon ◽

Carbon Cycling ◽

Belowground Biomass ◽

Freshwater Wetlands ◽

Wetland Creation ◽

Free Access ◽

Exclusion Experiment ◽

Herbivore Exclusion ◽

Sequestration Potential ◽

Natural Wetlands

Wetland ecosystems play a significant role in the global carbon cycle, and yet are increasingly threatened by human development and climate change. The continued loss of intact freshwater wetlands heightens the need for effective wetland creation and restoration. However, wetland structure and function are controlled by interacting abiotic and biotic factors, complicating efforts to replace ecosystem services associated with natural wetlands and making ecologically-driven management imperative. Increasing waterfowl populations pose a threat to the development and persistence of created wetlands, largely through intensive grazing that can shift vegetation community structure or limit desired plant establishment. This study capitalized on a long-term herbivore exclusion experiment to evaluate how herbivore management impacts carbon cycling and storage in a created wetland in Western New York, USA. Vegetation, above- and belowground biomass, soil carbon, carbon gas fluxes and decomposition rates were evaluated in control plots with free access by large grazers and in plots where grazers had been excluded for four years. Waterfowl were the dominant herbivore at the site. Grazing reduced peak growing season aboveground biomass by over 55%, and during the summer, gross primary productivity doubled in grazer exclusion plots. The shift in plant productivity led to a 34% increase in soil carbon after exclusion of grazers for five growing seasons, but no change in belowground biomass. Our results suggest that grazers may inhibit the development of soil carbon pools during the first decade following wetland creation, reducing the carbon sequestration potential and precluding functional equivalence with natural wetlands.

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Growing up aspen: ontogeny and trade-offs shape growth, defence and reproduction in a foundation species

Annals of Botany ◽

10.1093/aob/mcaa070 ◽

2020 ◽

Author(s):

Christopher T Cole ◽

Clay J Morrow ◽

Hilary L Barker ◽

Kennedy F Rubert-Nason ◽

Jennifer F L Riehl ◽

...

Keyword(s):

Intraspecific Variation ◽

Genotypic Variation ◽

Chemical Defence ◽

Extrafloral Nectaries ◽

Foundation Species ◽

Community Genetics ◽

Indirect Defence ◽

Juvenile Period ◽

Trade Offs ◽

Sex Marker

Abstract Background and Aims Intraspecific variation in foundation species of forest ecosystems can shape community and ecosystem properties, particularly when that variation has a genetic basis. Traits mediating interactions with other species are predicted by simple allocation models to follow ontogenetic patterns that are rarely studied in trees. The aim of this research was to identify the roles of genotype, ontogeny and genotypic trade-offs shaping growth, defence and reproduction in aspen. Methods We established a common garden replicating >500 aspen genets in Wisconsin, USA. Trees were measured through the juvenile period into the onset of reproduction, for growth, defence chemistry (phenolic glycosides and condensed tannins), nitrogen, extrafloral nectaries, leaf morphology (specific leaf area), flower production and foliar herbivory and disease. We also assayed the TOZ19 sex marker and heterozygosity at ten microsatellite loci. Key Results We found high levels of genotypic variation for all traits, and high heritabilities for both the traits and their ontogenetic trajectories. Ontogeny strongly shaped intraspecific variation, and trade-offs among growth, defence and reproduction supported some predictions while contradicting others. Both direct resistance (chemical defence) and indirect defence (extrafloral nectaries) declined during the juvenile stage, prior to the onset of reproduction. Reproduction was higher in trees that were larger, male and had higher individual heterozygosity. Growth was diminished by genotypic allocation to both direct and indirect defence as well as to reproduction, but we found no evidence of trade-offs between defence and reproduction. Conclusions Key traits affecting the ecological communities of aspen have high levels of genotypic variation and heritability, strong patterns of ontogeny and clear trade-offs among growth, defence and reproduction. The architecture of aspen’s community genetics – its ontogeny, trade-offs and especially its great variability – is shaped by both its broad range and the diverse community of associates, and in turn further fosters that diversity.

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Serial and parallel processing of tactual information in somatosensory cortex of rhesus monkeys

Journal of Neurophysiology ◽

10.1152/jn.1992.68.2.518 ◽

1992 ◽

Vol 68 (2) ◽

pp. 518-527 ◽

Cited By ~ 124

Author(s):

T. P. Pons ◽

P. E. Garraghty ◽

M. Mishkin

Keyword(s):

Substantial Reduction ◽

Receptive Fields ◽

Somatosensory System ◽

Encounter Rate ◽

Specific Information ◽

Tactile Information ◽

Cortical Areas ◽

Area 3A ◽

Area 3B ◽

Made In

1. Selective ablations of the hand representations in postcentral cortical areas 3a, 3b, 1, and 2 were made in different combinations to determine each area's contribution to the responsivity and modality properties of neurons in the hand representation in SII. 2. Ablations that left intact only the postcentral areas that process predominantly cutaneous inputs (i.e., areas 3b and 1) yielded SII recording sites responsive to cutaneous stimulation and none driven exclusively by high-intensity or "deep" stimulation. Conversely, ablations that left intact only the postcentral areas that process predominantly deep receptor inputs (i.e., areas 3a and 2) yielded mostly SII recording sites that responded exclusively to deep stimulation. 3. Ablations that left intact only area 3a or only area 2 yielded substantial and roughly equal reductions in the number of deep receptive fields in SII. By contrast, ablations that left intact only area 3b or only area 1 yielded unequal reductions in the number of cutaneous receptive fields in SII: a small reduction when area 3b alone was intact but a somewhat larger one when only area 1 was intact. 4. Finally, when the hand representation in area 3b was ablated, leaving areas 3a, 1, and 2 fully intact, there was again a substantial reduction in the encounter rate of cutaneous receptive fields. 5. The partial ablations often led to unresponsive sites in the SII hand representation. In SII representations other than of the hand no such unresponsive sites were found and there were no substantial changes in the ratio of cutaneous to deep receptive fields, indicating that the foregoing results were not due to long-lasting postsurgical depression or effects of anesthesia. 6. The findings indicate that modality-specific information is relayed from postcentral cortical areas to SII along parallel channels, with cutaneous inputs transmitted via areas 3b and 1, and deep inputs via areas 3a and 2. Further, area 3b provides the major source of cutaneous input to SII, directly and perhaps also via area 1. 7. The results are in line with accumulating anatomic and electrophysiologic evidence pointing to an evolutionary shift in the organization of the somatosensory system from the general mammalian plan, in which tactile information is processed in parallel in SI and SII, to a new organization in higher primates in which the processing of tactile information proceeds serially from SI to SII. The presumed functional advantages of this evolutionary shift are unknown.

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