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Bat activity on riparian zones and upper slopes in Australian timber production forests and the effectiveness of riparian buffers 总被引：1，自引：0，他引：1
Unlogged buffers are used to ameliorate impacts to riparian areas in timber production forests. One function of these buffers is to protect the biodiversity of riparian areas. We measured bat activity in buffered streams with ultrasonic detectors across four different stream orders in logged, regrowth and mature forests (60 sites). Bat activity, foraging rates and species richness were similar in buffered streams surrounded by logged, regrowth and mature forests, suggesting that riparian areas effectively provide habitat for foraging and commuting bats in selectively logged forests. Vespadelus pumilus was the only species that responded to logging history, with decreased activity in mature forests. We found higher activity on larger rather than smaller order streams, a pattern also not affected by logging history. Bat activity along paired forest trail flyways on upper slopes (60 sites) was measured simultaneously with riparian flyway activity (for a total of 120 sites) to determine the importance of riparian areas relative to other available flyways. Activity was higher on upper slopes than on small streams, but similar to levels on larger streams. Total foraging activity was similar between riparian zones and upper slopes. Upper slopes contained higher species diversity, with Chalinolobus gouldii, Miniopterus schreibersii, Mormopterus norfolkensis, Scotorepens sp., Vespadelus pumilus and, to a lesser extent, Vespadelus darlingtoni detected more often than along streams. Other species (Rhinolophus megaphyllus, Nyctophilus spp. and Miniopterus australis) were not affected by topography. Estimates of total vegetation cover and, in particular, rainforest cover, were negatively associated with bat activity, highlighting the need for management of forest ‘clutter’ in regrowth forests for a suite of bat species. Streams and forest trails provide areas of lower clutter, which assist in maintaining high species diversity in regrowth forests. Our results support the use of riparian buffers, and point to the need for greater recognition of tracks on upper slopes as important habitat. 相似文献
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We investigated the influence of landscape and wetland characteristics on pond-breeding amphibian assemblages in south-central New Hampshire, a relatively low populated and heavily forested region of the northeastern United States. This allowed us to better understand landscape influences in less disturbed areas, and to determine critical landscape disturbance thresholds, above which amphibians are negatively impacted. We sampled 61 wetlands for larval amphibians in 1998 and 1999 to examine the influence of forest cover and road density (at seven buffer distances between 100 and 2000 m) and wetland characteristics on larval amphibian assemblages. Assemblages were influenced primarily by forest cover and wetland hydroperiod. Species richness was most strongly influenced by the proportion of forest cover within 1000 m of the wetland. Several species were also influenced by forest cover, but were differentially influenced by buffer widths. Our study suggests that, at least in the northeast US, wetlands with <40% forest cover within a 1000 m radius may have depauperate larval amphibian assemblages, and forest cover above 60% within a 1000 m radius is likely to ensure species rich and abundant larval amphibian assemblages. Given the above, current federal and state regulations that focus amphibian protection efforts on narrow terrestrial buffers surrounding wetlands are likely to be inadequate. 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(11-12):1395-1410
Abstract Research has shown that measured water‐soluble phosphorus (WSP) from poultry litter might have been less than that released in the field. The effects of acidified extractions on soluble P (SP) concentrations were studied, and a buffer was selected to measure SP at pH 6.0, which is a target value for soil management in Georgia. Soluble P concentrations were extracted from poultry wastes at three pHs: 1) at natural pH, using deionized water (DIw); 2) after titrating DIw suspensions with 0.5N hydrochloric acid (HCl) to pH end‐points 3.0, 4.0, and 6.0; and 3) at pH 6.0 with buffers of sodium (Na) acetate, potassium hydrogen phthalate (KHP), 2‐(N‐morpholino) ethanesulphonic acid (MES), Na cacodylate, imidazole, N‐(2‐acetamido)‐2‐aminoethansulphonic acid (ACES), N‐(carbamoyl‐methyl) iminodiacetic acid (ADA), bis‐(2‐hydroxyethyl) imino]‐tris‐[(hydroxymethyl) methane (Bistris), and 1,4 piperazine‐bis‐(ethane sulphonic acid) (PIPES). Total SP increased 60% to 140% in suspensions acidified with HCl to pH 6.0 compared to suspensions at pH≥8. Dissolved unreactive P responded more (2× to 30×) than molybdate reactive P (20–100%). Buffers extracted more soluble minerals than suspensions acidified with HCl, probably because of their complexation ability. The most effective buffer was MES, because its effects seemed mainly due to acidification. 相似文献
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Chandrappa Gangaiah Amjad A. Ahmad 《Communications in Soil Science and Plant Analysis》2019,50(5):586-593
It is recommended to use ionic strength adjustment buffers to increase reading accuracy while measuring potassium (K+) concentrations in aqueous solutions by using ion-selective electrodes (ISEs). Three laboratory leachate column studies were conducted to evaluate the efficiency of two buffers, 2.5 M sodium perchlorate (NaClO4) and 2.5 M sodium chloride (NaCl), in measuring K+ concentrations in three media types (peat moss, Oxisols, and Mollisols soils). Three algae species, KCl, and KNO3 were applied to provide 112 and 336 kg K/ha. Leachate samples were collected to a total of 16 weeks and measured using a K-ISE. The K+ data from the three trials showed a highly significant (r ~ 0.99) correlation between the two buffers. T-Test results showed highly significant (P < 0.01) differences between unbuffered and the two buffered solutions. However, there were no significant differences between the two buffered solutions, under the peat moss, Oxisols, and Mollisols soils. The results suggest that the least expensive buffer of 2.5 M NaCl is as accurate as NaClO4 in such aqueous solutions. 相似文献
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