排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
2.
3.
4.
Gertjan de Koning Michele Kellerhals Cisca van Meurs Bernard Witholt 《Journal of Polymers and the Environment》1996,4(4):243-252
Poly[(R)-3-hydroxyalkanoates] (PHAs) are biopolymers stored by bacteria, which are currently receiving much attention because of their potential as renewable and biodegradable plastics. Most well-known representatives are poly[(R)-3-hydroxybutyrate] and its copolymers with 3-hydroxyvalerate, which have been commercialized under the trademark Biopol. In addition to these rigid materials, the elastomeric medium-chain length PHAs (mcl-PHAs) produced by fluorescent Pseudomonads are now emerging. The present review aims to survey the important developments concerning research and application prospects of mcl-PHAs. 相似文献
5.
Bart Wouters Marijn Nijssen Gertjan Geerling Hein Van Kleef Eva Remke Wilco Verberk 《Journal of Coastal Conservation》2012,16(1):89-99
Encroachment of tall grasses and shrubs in coastal dunes has resulted in loss of vegetation heterogeneity. This is expected
to have negative effects on animal diversity. To counteract encroachment and develop structural heterogeneity grazing is a
widely used management practice. Here, we aim to functionally interpret changes in vegetation composition and configuration
following grazing management on habitat suitability for sand lizards. Aerial photographs taken over a period of 16 years were
used to quantify changes in vegetation composition. A GIS-based method was developed to calculate habitat suitability for
sand lizards in a spatially explicit manner, encompassing differences in vegetation structure and patch size. From 1987 to
2003 dune vegetation shifted from small patches of moss and sand to larger patches covered by shrubs and grasses. Grazing
management did not have any significant effect on the overall level of heterogeneity, measured as habitat suitability for
sand lizards. However, on a more local scale highly suitable patches in 1987 were deteriorating whereas unsuitable patches
became more suitable in 2003. This inversion results from a broad shift with shrubs being a limiting habitat element in 1987
to sandy patches being the limiting element in 2003. Future changes are believed to negatively impact sand lizards. The habitat
suitability model has proven to be a useful tool to functionally interpret changes in coastal dune vegetation heterogeneity
from an animal’s perspective. Further research should aim to include multiple species operating on different scale levels
to fully capture the natural landscape dynamics. 相似文献
1