Making Waste Profitable: Yak Dung Derived Carbon for High-Performance Supercapacitors

With the continuous increase in the demand for energy storage equipment, it is imperative to develop new electrode materials with high specific capacitance. In this study, yak dung derived carbon materials (N-YD) were prepared by a simple, economical, and effective method, and it was applied as a supercapacitor electrode material. The N-YD-800 material exhibited high nitrogen content, as well as a large number of multipore structures, which were beneficial to improve the capacitance performance. N-YD-800 exhibited an excellent specific capacitance (346.3[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], good rate performance (56.6% from 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] to 10[Formula: see text]A[Formula: see text]g[Formula: see text], and excellent cycling stability (93.3% after 5000 cycles). This study provided a new method for the treatment of livestock and poultry manure resources, affording a cost-effective, easy-to-use carbon source to solve the problem of nonrenewable energy.

Short-term study on the yak dung seed bank on the Qinghai-Tibetan Plateau: effects of grazing season, seed characteristics and forage preferences

Aims Viable seeds in herbivore dung constitute the dung seed bank, and the contribution of livestock dung to this seed bank in grazing pastures is often overlooked. Grazing season (warm and cold), seed characteristics (size and shape), and forage preference are the main factors that affect the size and composition of the dung seed bank and ultimately affect grassland ecology. However, how these three factors interact is unclear. Methods We collected yak dung as well as seeds of the common plant species from warm- and cold-season alpine meadows in northeastern Qinghai-Tibetan Plateau, and explored how grazing season (warm and cold), seed characteristics (size and shape) and foraging preferences (temporary cages method) affects yak dung seedling density, richness and diversity in an alpine pasture. Results Forty-three plant species (mainly perennials) germinated from yak dung. Dung seedling density, richness, and diversity did not differ significantly between the two grazing seasons. Small to medium-sized spherical seeds (seed size < 10 mg, shape index < 0.5) had the greatest germination potential. Conclusions Yaks vary their forage preference depending on the season (phenological period), and endozoochory occurs throughout both grazing seasons. Seed shape and size directly regulate the dung seedling density, richness, and diversity. Dung seedlings increase the heterogeneity of the aboveground vegetation near the microsites of the dung pieces and therefore promote grassland patching. Our study demonstrates that grazing season, seed characteristics, and yak forage preferences affect the dung seed bank in grazing ecosystems.

Yak Dung Seed Bank on the Qinghai-Tibetan Plateau: Effects of Grazing Season, Seed Characteristics and Forage Preferences

AimsViable seeds in herbivore dung constitute the dung seed bank, and the contribution of livestock dung to this seed bank in grazing pastures is often overlooked. Grazing season (warm and cold), seed characteristics (mass and shape), and forage preference are the main factors that affect the size and composition of the dung seed bank and ultimately affect grassland ecology. However, how these three factors interact is unclear. Methodswe collected yak dung as well as seeds of the common plant species from warm- and cold-season alpine meadows in northeastern Qinghai-Tibetan Plateau, and explored how grazing season (warm and cold), seed characteristics (size and shape) and foraging preferences (temporary cages method) affects yak dung seedling density, richness and diversity in an alpine pasture on the northeastern Qinghai-Tibetan Plateau. ResultsForty-three plant species (mainly perennials) could germinate from yak dung. Dung seedling density, richness, and diversity did not differ significantly between the two grazing seasons. Small-to-medium-sized spherical seeds (seed mass < 10 mg, shape index < 0.5) had the greatest germination potential. ConclusionsYaks vary their forage preference depending on the season (phenological period), and endozoochory occurs throughout both grazing seasons. Seed shape and mass directly regulate the dung seedling density, richness, and diversity. Dung seedlings increase the heterogeneity of the aboveground vegetation near the microsites of the dung pieces and therefore promote grassland patching. Our study demonstrates that grazing season, seed characteristics, and yak forage preferences affect the dung seed bank in grazing ecosystems.