Forage selection by collared pikas, Ochotona collaris, under varying degrees of predation risk

2004 ◽  
Vol 82 (4) ◽  
pp. 533-540 ◽  
Author(s):  
Shawn Morrison ◽  
Luc Barton ◽  
Peter Caputa ◽  
David S Hik
Keyword(s):  
Predation Risk ◽  
Plant Species ◽  
Potential Risk ◽  
Nutritional Quality ◽  
Individual Plant ◽  
Negative Effects ◽  
Trade Off ◽  
Ochotona Collaris ◽  
Forage Species ◽  
Predator Abundance

The effects of predation risk on foraging behavior often result in a trade-off between obtaining food and seeking shelter and may alter the selectivity of herbivores for individual plant species. We experimentally measured forage selection by a small alpine herbivore, the collared pika (Ochotona collaris (Nelson, 1893)), using a cafeteria-style arrangement of six potential forage species at five levels of predation risk. Contrary to our prediction, haying pikas did not switch preferences for forage species of different nutritional quality as predation risk increased. However, the total amount of forage removed was inversely related to risk, and the addition of cover at treatments of greatest potential risk ameliorated the negative effects of higher predation risk. The reasons for increased preference for poorer quality forage species in 2002 relative to 2000 are currently unknown but may reflect changes in predator abundance, forage quality, or increased competition for limited forage resources.

The effect of leguminous plant species onCallosobruchus maculatus(Coleoptera: Bruchidae) and its egg parasitoidUscana lariophaga(Hymenoptera: Trichogrammatidae)

1998 ◽  
Vol 88 (1) ◽  
pp. 93-99 ◽  
Author(s):  
A. van Huis ◽  
M. de Rooy
Keyword(s):  
Sex Ratio ◽  
Plant Species ◽  
Nutritional Quality ◽  
Development Time ◽  
Callosobruchus Maculatus ◽  
Egg Parasitoid ◽  
The Other ◽  
Leguminous Plant ◽  
Trade Off ◽  
Storage Pest

AbstractThe performance of the egg parasitoidUscana lariophagaSteffan was studied when reared on eggs of the bruchid storage pest,Callosobruchus maculatus(Fabricius) developing in seeds of cowpea, chickpea and pigeonpea. The beetle laid more and larger eggs on pigeonpea than on cowpea and chickpea, indicating that there was not a trade-off between number and size of the eggs. The bruchid larvae reared on pigeonpea exhibited a longer development time and a higher mortality than those reared on cowpea and chickpea. The resulting males weighed less than those reared on cowpea and chickpea. The trichogrammatidU. lariophagaparasitized more eggs whenC. maculatuswas reared on chickpea than when reared on the other hosts. Parasitoid larvae developed slowest and had the highest mortality in eggs ofC. maculatusreared on pigeonpea compared to those reared on cowpea and chickpea; the sex ratio (% of females) of the resulting adults was also higher. The high mortality and long development time ofC. maculatusreared on pigeonpea indicated that this legume was less favourable toC. maculatusthan chickpea or cowpea. This was probably also true for the parasitoid since the mortality was higher and development longer in eggs ofC. maculatusreared on pigeonpea compared to those reared on cowpea and chickpea. Therefore, when host eggs were larger and of lower nutritional quality, the proportion of female egg parasitoids was greater.

scholarly journals The influence of forest series and stand age on individual plant species nutritional quality in a mixed-conifer forest

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. 1728-1732
Author(s):  
Timothy DelCurto ◽  
Noah G Davis ◽  
Samuel A Wyffels ◽  
Daalkhaijav Damiran ◽  
Enkhjargal Darambazar ◽  
...  
Keyword(s):  
Plant Species ◽  
Nutritional Quality ◽  
Stand Age ◽  
Individual Plant ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Mixed Conifer Forest

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

Plant induced spatial distribution of nematodes in a semi-natural grassland

Nematology ◽  
2007 ◽  
Vol 9 (1) ◽  
pp. 131-142 ◽  
Author(s):  
Maria Viketoft
Keyword(s):  
Multivariate Analysis ◽  
Spatial Distribution ◽  
Spatial Structure ◽  
Plant Species ◽  
Trifolium Repens ◽  
Individual Plant ◽  
Nematode Communities ◽  
The Family ◽  
Natural Grassland ◽  
Nematode Fauna

AbstractThis study describes the nematode community in a semi-natural grassland and investigates if certain individual plant species can cause a spatial structure in the nematode fauna. Nematode communities were analysed in soil under Trifolium repens, Festuca ovina and from randomly taken samples. Seventy-nine nematode genera were identified. Some of the species found have not previously been reported from Sweden. Multivariate analysis separated the nematode communities associated with the two selected plant species from each other, and several individual nematode genera differed in abundance between the plant species. Trifolium repens supported greater populations of the plant feeder Tylenchorhynchus and the bacterial feeders Eucephalobus, Chiloplacus, Eumonhystera and Panagrolaimus, but fewer numbers of the bacterial feeder Achromadora. Soil under F. ovina contained more nematodes from the family Alaimidae. A comparison is given with other studies from grassland systems in Sweden.

scholarly journals Assessment of the Potential Risk of Rock-Climbing for Cliff Plant Species and Natural Protected Areas of Spain

2021 ◽  
Vol 9 ◽  
Author(s):  
Indradatta deCastro-Arrazola ◽  
Martí March-Salas ◽  
Juan Lorite
Keyword(s):  
Protected Areas ◽  
Plant Species ◽  
Potential Risk ◽  
Field Studies ◽  
Rock Climbing ◽  
Future Research ◽  
Small Scale ◽  
Potential Threat ◽  
Natural Protected Areas ◽  
Priority Species

In recent years, the popularity of rock-climbing has grown tremendously, setting an increasing pressure on cliff habitats. Climbing may be particularly harmful in the Mediterranean biome due to its appropriate environmental conditions for climbing. A few studies have identified the effect of climbing on plant diversity at a small-scale (namely locally or even just in specific climbing areas). However, no studies exist assessing the potential risk of rock-climbing on a broad-scale (e.g., regional or national). The study aims to identify the priority locations and priority cliff plant species in Spain to focus future study efforts. Spain was selected because it is a plant biodiversity hotspot, with a great diversity of endemic and endangered species, and one of the most popular destinations for climbers. We used a geographic information system-based approach to model the spatial concurrence among Spanish climbing areas (and climbing intensity), natural protected areas (NPAs), and distribution of threatened cliff plants (and their IUCN threat category). We found that 53.5% of climbing areas in Spain are located within a NPA, most of them falling into NPAs of medium protection level. We mapped 151 threatened cliff plants, identifying four medium priority Mediterranean locations and eight priority species in which future research efforts should be focused. High-priority study locations are absent in Spain according to our spatial modeling. For the first time on a national scale, this study identifies areas in which climbing represents a potential threat for cliff habitats and threatened plants. These findings contribute to designing field studies on the effects of rock-climbing on Mediterranean cliffs, laying the groundwork for a sustainable, yet challenging, balance between the protection of these unique habitats and rock-climbing.

PHYSIOLOGICAL AND BEHAVIORAL RESPONSES TO PREDATORS SHAPE THE GROWTH/PREDATION RISK TRADE-OFF IN DAMSELFLIES

Ecology ◽  
2001 ◽  
Vol 82 (6) ◽  
pp. 1535-1545 ◽  
Author(s):  
Mark A. McPeek ◽  
Margaret Grace ◽  
Jean M. L. Richardson
Keyword(s):  
Predation Risk ◽  
Behavioral Responses ◽  
Trade Off

Impacts of erosion control treatments on native vegetation recovery after severe wildfire in the Eastern Cascades, USA

2010 ◽  
Vol 19 (4) ◽  
pp. 490 ◽  
Author(s):  
Erich K. Dodson ◽  
David W. Peterson ◽  
Richy J. Harrod
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Native Species ◽  
Plant Cover ◽  
Plant Species Richness ◽  
Tree Regeneration ◽  
Vegetation Recovery ◽  
Native Vegetation ◽  
Individual Plant ◽  
Native Plant

Slope stabilisation treatments like mulching and seeding are used to increase soil cover and reduce runoff and erosion following severe wildfires, but may also retard native vegetation recovery. We evaluated the effects of seeding and fertilisation on the cover and richness of native and exotic plants and on individual plant species following the 2004 Pot Peak wildfire in Washington State, USA. We applied four seeding and three fertilisation treatments to experimental plots at eight burned sites in spring 2005 and surveyed vegetation during the first two growing seasons after fire. Seeding significantly reduced native non-seeded species richness and cover by the second year. Fertilisation increased native plant cover in both years, but did not affect plant species richness. Seeding and fertilisation significantly increased exotic cover, especially when applied in combination. However, exotic cover and richness were low and treatment effects were greatest in the first year. Seeding suppressed several native plant species, especially disturbance-adapted forbs. Fertilisation, in contrast, favoured several native understorey plant species but reduced tree regeneration. Seeding, even with native species, appears to interfere with the natural recovery of native vegetation whereas fertilisation increases total plant cover, primarily by facilitating native vegetation recovery.

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