Consistent shift in nutritional ecology of ants reveals trophic flexibility across alpine tree‐line ecotones

AbstractNatural salt lick (sira) is a strategic localisation for ecological wildlife assemblage to exhibit geophagy which may act as a population dynamic buffer of prey and predators. Undoubtedly, many agree that geophagy at natural licks is linked to nutritional ecology, health and assembly places facilitating social interaction of its users. Overall, natural salt licks not only save energy of obtaining nutrient leading to health maintenance but also forms the basis of population persistence. The Royal Belum Rainforest, Malaysia (Royal Belum) is a typical tropical rainforest in Malaysia rich in wildlife which are mainly concentrated around the natural salt lick. Since this is one of the most stable fauna ecology forest in Malaysia, it is timely to assess its impact on the Malayan tiger (Panthera tigris) home range dynamics. The three-potential home ranges of the Malayan tiger in this rainforest were selected based on animal trails or foot prints surrounding the salt lick viz (e.g. Sira Kuak and Sira Batu; Sira Rambai and Sira Buluh and Sira Papan) as well as previous sightings of a Malayan tiger in the area, whose movement is dependent on the density and distribution of prey. Camera traps were placed at potential animal trails surrounding the salt lick to capture any encountered wildlife species within the area of the camera placements. Results showed that all home ranges of Malayan tiger were of no significance for large bodied prey availability such as sambar deer (Rusa unicolor), and smaller prey such as muntjacs (Muntiacus muntjac) and wild boar (Sus scrofa). Interestingly, all home range harbour the Malayan tiger as the only sole predator. The non-significance of prey availability at each home range is attributed to the decline of the Malayan tiger in the rainforest since tigers are dependant on the movement of its preferred prey surrounding natural salt licks. Thus, the information from this study offers fundamental knowledge on the importance of prey-predator interaction at salt lick which will help in designing strategy in rewilding or rehabilitation programs of the Malayan tiger at the Royal Belum Rainforest.

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Tree line advance reduces mixing and oxygen concentrations in arctic‐alpine lakes through wind sheltering and organic carbon supply

Global Change Biology ◽

10.1111/gcb.15660 ◽

2021 ◽

Author(s):

Marcus Klaus ◽

Jan Karlsson ◽

David Seekell

Keyword(s):

Organic Carbon ◽

Alpine Lakes ◽

Tree Line ◽

Carbon Supply ◽

Wind Sheltering ◽

Oxygen Concentrations

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Carbon and nutrient physiology in shrubs at the upper limits: a multi-species study

Journal of Plant Ecology ◽

10.1093/jpe/rtaa097 ◽

2020 ◽

Author(s):

Xue Wang ◽

Fei-Hai Yu ◽

Yong Jiang ◽

Mai-He Li

Keyword(s):

Fine Roots ◽

Soluble Sugar ◽

Soluble Sugars ◽

Growing Season ◽

Interactive Effects ◽

Tree Line ◽

Shrub Species ◽

Nutrient Physiology ◽

Upper Limits ◽

Species Study

Abstract Aims Carbon and nutrient physiology of trees at their upper limits have been extensively studied, but those of shrubs at their upper limits have received much less attention. The aim of this study is to examine the general patterns of non-structural carbohydrates (NSCs), nitrogen (N) and phosphorous (P) in shrubs at the upper limits, and to assess whether such patterns are similar to those in trees at the upper limits. Methods Across Eurasia, we measured the concentrations of soluble sugars, starch, total NSCs, N and P in leaves, branches and fine roots (< 0.5 cm in diameter) of five shrub species growing at both the upper limits and lower elevations in both summer (peak growing season) and winter (dormancy season). Important Findings Neither elevation nor season had significant effects on tissue N and P concentrations, except for lower P concentrations in fine roots in winter than in summer. Total NSCs and soluble sugars in branches were significantly higher in winter than in summer. There were significant interactive effects between elevation and season for total NSCs, starch, soluble sugars and the ratio of soluble sugar to starch in fine roots, showing lower soluble sugars and starch in fine roots at the upper limits than at the lower elevations in winter but not in summer. These results suggest that the carbon physiology of roots in winter may play an important role in determining the upward distribution of shrubs, like that in the alpine tree-line trees.

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Plant Metabolites Involved in the Differential Development of a Heliantheae-Specialist Insect

Metabolites ◽

10.3390/metabo11030134 ◽

2021 ◽

Vol 11 (3) ◽

pp. 134

Author(s):

Marília Elias Gallon ◽

Leonardo Gobbo-Neto

Keyword(s):

Larval Development ◽

Sesquiterpene Lactones ◽

Nutritional Ecology ◽

Plant Metabolites ◽

Plant Insect Interactions ◽

Tridax Procumbens ◽

Integrative Studies ◽

Specialist Insect ◽

Insect Interactions ◽

New Research

Balanced nutritional intake is essential to ensure that insects undergo adequate larval development and metamorphosis. Integrative multidisciplinary approaches have contributed valuable insights regarding the ecological and evolutionary outcomes of plant–insect interactions. To address the plant metabolites involved in the larval development of a specialist insect, we investigated the development of Chlosyne lacinia caterpillars fed on Heliantheae species (Tithonia diversifolia, Tridax procumbens and Aldama robusta) leaves and determined the chemical profile of plants and insects using a metabolomic approach. By means of LC-MS and GC-MS combined analyses, 51 metabolites were putatively identified in Heliantheae species and C. lacinia caterpillars and frass; these metabolites included flavonoids, sesquiterpene lactones, monoterpenoids, sesquiterpenoids, diterpenes, triterpenes, oxygenated terpene derivatives, steroids and lipid derivatives. The leading discriminant metabolites were diterpenes, which were detected only in A. robusta leaves and insects that were fed on this plant-based diet. Additionally, caterpillars fed on A. robusta leaves took longer to complete their development to the adult phase and exhibited a greater diapause rate. Hence, we hypothesized that diterpenes may be involved in the differential larval development. Our findings shed light on the plant metabolites that play roles in insect development and metabolism, opening new research avenues for integrative studies of insect nutritional ecology.

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A Comparison of some Upland and Valley Soils in the Ungava-Labrador Peninsula

Géographie physique et Quaternaire ◽

10.7202/032566ar ◽

2007 ◽

Vol 38 (3) ◽

pp. 243-256 ◽

Cited By ~ 4

Author(s):

William H. Hendershot

Keyword(s):

Soil Temperature ◽

Black Spruce ◽

Carbon Accumulation ◽

Shallow Depth ◽

Soil Profiles ◽

Tree Line ◽

Climatic Regions ◽

Coarse Texture ◽

Active Mixing ◽

Extractable Iron

ABSTRACT Thirteen soil profiles from northern Québec and Labrador, Canada, near the northern tree-line, were sampled and analysed. Five of these, located on poorly to imperfectly drained sites, are strongly cryoturbated soils with permafrost at a shallow depth. Below the surface horizon they have very uniform profile distributions of pH, carbon and extractable iron and aluminum due to the active mixing of the horizons. The eight soils from well-drained sites have profiles similar to those of soils in similar settings in more temperate climatic regions. One of these, developed in one of the most northerly valleys having a black spruce-larch forest vegetation, has the characteristics of a podzol (spodosol) except that the podzolic B (spodic) horizon is too thin. The other seven profiles all have color B horizons, although the coarse texture prevents their classification as cambic horizons; these soils all have carbon-rich A horizons varying in thickness from 1.5 to 20 cm. Soil temperature at 50 cm depth closely follows the elevational and latitudinal distribution of the soils; a range of 0 to 10° C was observed. Soil development, measured as depth of solum, organic carbon accumulation or degree of B horizon development, is closely related to soil temperature and site position. The presence of permanently frozen ice layers at shallow depth has a marked influence on soil genesis and the properties of the resultant soils.

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