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381.
de Paula FR Ferraz SF Gerhard P Vettorazzi CA Ferreira A 《Environmental management》2011,48(4):750-763
Riparian forests are important for the structure and functioning of stream ecosystems, providing structural components such
as large woody debris (LWD). Changes in these forests will cause modifications in the LWD input to streams, affecting their
structure. In order to assess the influence of riparian forests changes in LWD supply, 15 catchments (third and fourth order)
with riparian forests at different conservation levels were selected for sampling. In each catchment we quantified the abundance,
volume and diameter of LWD in stream channels; the number, area and volume of pools formed by LWD and basal area and tree
diameter of riparian forest. We found that riparian forests were at a secondary successional stage with predominantly young
trees (diameter at breast height <10 cm) in all studied streams. Results showed that basal area and diameter of riparian forest
differed between the stream groups (forested and non-forested), but tree density did not differ between groups. Differences
were also observed in LWD abundance, volume, frequency of LWD pools with subunits and area and volume of LWD pools. LWD diameter,
LWD that form pools diameter and frequency of LWD pools without subunits did not differ between stream groups. Regression
analyses showed that LWD abundance and volume, and frequency of LWD pools (with and without subunits) were positively related
with the proportion of riparian forest. LWD diameter was not correlated to riparian tree diameter. The frequency of LWD pools
was correlated to the abundance and volume of LWD, but characteristics of these pools (area and volume) were not correlated
to the diameter of LWD that formed the pools. These results show that alterations in riparian forest cause modifications in
the LWD abundance and volume in the stream channel, affecting mainly the structural complexity of these ecosystems (reduction
in the number and structural characteristics of LWD pools). Our results also demonstrate that riparian forest conservation
actions must consider not only its extension, but also successional stage to guarantee the quantity and quality of LWD necessary
to enable the structuring of stream channels. 相似文献
382.
Kitanovski Zoran Hovorka Jan Kuta Jan Leoni Cecilia Prokeš Roman Sáňka Ondřej Shahpoury Pourya Lammel Gerhard 《Environmental science and pollution research international》2021,28(42):59131-59140
Environmental Science and Pollution Research - Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and... 相似文献
383.
Ivančev-Tumbas Ivana Lammel Gerhard 《Environmental science and pollution research international》2021,28(42):59317-59318
Environmental Science and Pollution Research - Recently, nearly 500 study programmes related to environmental disciplines were detected in Europe (Lammel et al, Environ Sci Pollut Res 21:7211-7218... 相似文献
384.
Storch G 《Die Naturwissenschaften》2008,95(10):927-930
Most living mammal orders, including our own, started their career during the first 10 million years of the Cenozoic, the
Age of Mammals. The fossil record documents that early Paleogene adaptive radiations of various clades included tiny species
of the size of living shrews. Remains of particularly diminutive limb bones are described from the late Paleocene site of
Walbeck, Sachsen-Anhalt. Discovered in 1939, it has remained the only known Paleocene mammal-bearing locality from Germany.
The remains are referred to the family Adapisoriculidae, which is considered on the basis of the present postcranial evidence
to represent plesiadapiform primates rather than alleged lipotyphlan insectivores as previously proposed. The Walbeck fossils
compete with the Early Eocene species Toliapina vinealis from Europe and Picromomys petersonorum from North America for the status of the smallest known primate, fossil and living. Their estimated body weights are as small
as 10 g. The limb bones show features related to enhanced flexion at the elbow and hip joint, suggesting arboreal habits and
environments such as terminal branches. The diminutive size and tooth morphology suggest feeding on small insects and other
invertebrates. Postcranials are important to assess early radiations, such tiny specimens as the present ones are extremely
scarce in the fossil record, however. 相似文献
385.
Socio-economic driving forces of land-use change in Kunshan, the Yangtze River Delta economic area of China 总被引:28,自引:0,他引:28
This paper analyzes characteristics, major driving forces and alternative management measures of land-use change in Kunshan, Jiangsu province, China. The study used remote sensing (RS) maps and socio-economic data. Based on RS-derived maps, two change matrices were constructed for detecting land-use change between 1987 and 1994, and between 1994 and 2000 through pixel-to-pixel comparisons. The outcomes indicated that paddy fields, dryland, and forested land moderately decreased by 8.2%, 29% and 2.6% from 1987 to 1994, and by 4.1%, 7.6% and 8% from 1994 to 2000, respectively. In contrast, the following increased greatly from 1987 to 1994: artificial ponds by 48%, urban settlements by 87.6%, rural settlements by 41.1%, and construction land by 511.8%. From 1994 to 2000, these land covers increased by 3.6%, 28.1%, 23.4% and 47.1%, respectively. For the whole area, fragmentation of land cover was very significant. In addition, socio-economic data were used to analyze major driving forces triggering land-use change through bivariate analysis. The results indicated that industrialization, urbanization, population growth, and China's economic reform measures are four major driving forces contributing to land-use change in Kunshan. Finally, we introduced some possible management measures such as urban growth boundary (UGB) and incentive-based policies. We pointed out that, given the rapidity of the observed changes, it is critical that additional studies be undertaken to evaluate these suggested policies, focusing on what their effects might be in this region, and how these might be implemented. 相似文献