Xue Yan

Environmental strategies analysis of cohousing based on ecological footprint

Cohousing is a type of housing in which residents actively participate in the design and operation of their own neighborhoods. In order to reduce construction and living costs, most of cohousing reach a consensus of resource sharing and energy saving on the common values of pro-environment and sustainability. Five dimensions, site planning and design, food consumption, trip mode, resource usage and energy system, enter into environmental strategies analysis and assessment of cohousing based on ecological footprint. It is concluded that compact layout and building size; cutback are direct ways to reduce footprint of cohousing; sharing common meals and resources, less driving and more recycling are proactive and effective environmental strategies by altering behaviors and lifestyle of cohousers; using renewable energy and energy-saving technologies to reduce energy consumption is an active approach conventionally applied in cohousing to reduce human ecological footprint.

Species richness and phylogenetic diversity of seed plants across vegetation zones of Mount Kenya, East Africa

Abstract Mount Kenya is of ecological importance in tropical east Africa due to the dramatic gradient in vegetation types that can be observed from low to high elevation zones. However, species richness and phylogenetic diversity of this mountain have not been well studied. Here, we surveyed distribution patterns for a total of 1,335 seed plants of this mountain and calculated species richness and phylogenetic diversity across seven vegetation zones. We also measured phylogenetic structure using the net relatedness index (NRI) and the nearest species index (NTI). Our results show that lower montane wet forest has the highest level of species richness, density, and phylogenetic diversity of woody plants, while lower montane dry forest has the highest level of species richness, density, and phylogenetic diversity in herbaceous plants. In total plants, NRI and NTI of four forest zones were smaller than three alpine zones. In woody plants, lower montane wet forest and upper montane forest have overdispersed phylogenetic structures. In herbaceous plants, NRI of Afro‐alpine zone and nival zone are smaller than those of bamboo zone, upper montane forest, and heath zone. We suggest that compared to open dry forest, humid forest has fewer herbaceous plants because of the closed canopy of woody plants. Woody plants may have climate‐dominated niches, whereas herbaceous plants may have edaphic and microhabitat‐dominated niches. We also proposed lower and upper montane forests with high species richness or overdispersed phylogenetic structures as the priority areas in conservation of Mount Kenya and other high mountains in the Eastern Afro‐montane biodiversity hotspot regions.

The Influence of Culture Factors on Abiotic Loss of PAHs and Their Derivatives from Different Media

To obtain reliable estimates for the abiotic loss of polycyclic aromatic hydrocarbons (PAHs) and its derivatives from experimental media, one has to consider the effects of culture factors, such as light and dissolved organic C (DOC). We studied the abiotic loss of two PAHs and three derivatives of naphthalene from three different culture media in laboratory-experiment. The extent of their disappearance was monitored over five days using benzene extraction and HPLC analysis method. The results indicated that half of the abiotic loss occurred in the first 24 hr of experiment except for anthracene. Anthracene was the most persistent one in the media among the five chemicals in the experiment and its half-life was much longer than those of the others. Kinetic analysis of the results determined that the losing rate of the five test chemicals was first order. Light is the most important factor for PAHs abiotic loss and the addition of DOC enhanced slightly the removal of PAHs and its derivatives exposed to the light. Furthermore, the different substituent groups or the substituent sites of the test chemicals also affected the loss rate and half-life of organic matter.