澳门翼手类物种多样性调查

2009 ～2012 年,对澳门翼手目(蝙蝠)物种多样性进行了调查。结果共捕捉到10 个物种,属5 科8 属,其中包括澳门原来记载的2 个物种,即蹄蝠科的大蹄蝠(Hipposideros armiger)和蝙蝠科的东亚伏翼(Pipistrellus abramus);本研究新增加8 个物种,即狐蝠科的犬蝠(Cynopterus sphinx) 和棕果蝠(Rousettus leschenaulti),鞘尾蝠科的黑髯墓蝠(Taphozous melanopogon),菊头蝠科的菲菊头蝠(Rhinolophus pusillus),以及蝙蝠科的大足鼠耳蝠(Myotis ricketti)、普通伏翼(P. pipistrellus)、普通长翼蝠(Miniopterus schreibersi) 和南长翼蝠(M. pusillus)。另外,通过野外录音和分析,并与已发表物种声音特征比较核对,发现菊头蝠科和蹄蝠科各一种,前者可能是泰国菊头蝠(R. siamensis)或者中菊头蝠(R. affinis),后者可能是果树蹄蝠(H. pomona) 或者三叶蹄蝠(Aselliscus stoliczkanus)。本文对已捕捉10 种蝙蝠的分布、形态特征和回声定位叫声特征进行报道,同时对其种群数量和保护现状进行了讨论。保护蝙蝠栖息生境(洞穴、古老建筑和蒲葵树等) 对保护澳门蝙蝠物种多样性至关重要。     

香港米埔湿地生态功能价值估算

香港米埔湿地以红树植物为主要植物群落,是热带、亚热带海岸典型的湿地类型,它能够提供给人类包括物质和服务在内的各项生态服务。运用多种生态经济学方法,包括市场价格法、重置成本法、旅游费用法和问卷调查法等,评估香港米埔红树林湿地的生态功能价值;总价值包括使用价值和非使用价值,使用价值包括物质生产、调节大气组分、净化水体、旅游、文化教育等,非使用价值主要指红树林湿地的存在价值。最终得到香港米埔红树林湿地2003年实现的生态功能价值为HK|S 208.79×106,探讨了现在估算过程中存在的不足,并对今后的估算研究提出了合理性建议。     

海南岛东寨港红树林群落甲烷通量研究

 采用静态箱法对海南东寨港4个站位的5个红树林群落的土壤甲烷通量进行了研究,结果表明林地土壤平均甲烷通量为0.81mg·m-2·d-1。利用聚乙烯袋密闭法测定了6种红树植物叶片的甲烷通量,发现红树植物叶片具有吸收大气甲烷的效应。通过海莲(Bruguiera sexangula)红树林的研究还表明,林地土壤甲烷通量的日变化与林内潮水淹浸状况有关。海莲林不同滩面土壤甲烷通量的差异与土壤含水量有关。土壤甲烷通量的季节差异因植被类型或土壤性质不同而表现为两种形式。     

Impact of invasive apple snails in Hong Kong on wetland macrophytes,nutrients, phytoplankton and filamentous algae

1. Grazing by invasive species can affect many aspects of an aquatic system, but most studies have focused on the direct effects on plants. We conducted mesocosm and laboratory experiments to examine the impact of the invasive apple snail Pomacea canaliculata on macrophytes, filamentous algae, nutrients and phytoplankton. 2. In a freshwater pond, we confined 500 g of Myriophyllum aquaticum or Eichhornia crassipes with 0, 2, 4 or 8 apple snails in 1 m × 1 m × 1 m enclosures for approximately 1 month. Apple snails grazed heavily on both species of macrophytes, with higher overall weight losses at higher snail densities. The damage patterns differed between the two macrophytes. In M. aquaticum, both leaves and stems suffered from substantial herbivory, whereas in E. crassipes, only the roots suffered significant weight reduction. 3. In addition to grazing on macrophytes, apple snails appeared to have controlled the growth of filamentous algae, as these did not develop in the snail treatments. The ability of P. canaliculata to control filamentous algae was supported by a laboratory experiment where the consumption was as high as 0.25 g g⁻¹ snail DW d⁻¹. Because of a lack of native herbivorous snails in the pond, the growth of filamentous algae (mainly Spirogyra sp.) reached 80.3 g m⁻², forming a spongy pond scum in the no‐apple snail control. Together with previous reports that apple snails could eat the juveniles and eggs of other freshwater snails, our results indicated that P. canaliculata could have out‐competed native herbivorous snails from the pond by predation on their juveniles or eggs. Alternatively, P. canaliculata might have out‐competed them by monopolisation of food resources. 4. Nitrogen and phosphorous concentrations remained low throughout both experiments and were not correlated with apple snail density. The treatment effects on chlorophyll a (Chl a) and phytoplankton composition varied in the two experiments. In the M. aquaticum experiment, with increasing snail density, Chl a increased, and the phytoplankton community became dominated by Cryptophyceae. In the E. crassipes experiment, Chl a level was independent of snail density, but with increasing snail density, the phytoplankton community became co‐dominated by Cryptophyceae, Chlorophyceae and Bacillariophyceae. 5. Given the multiple effects of P. canaliculata on wetland biodiversity and function, management strategies should be developed to prevent its further spread. In invaded wetlands, strategies should be developed to eradicate the apple snail and re‐introduce native snails which can control the development of filamentous algae.     

Zinc Effects on Growth, Pigmentation and Antibacterial Activity of Monascus purpureus

Growth, pigmentation and antibacterial activity of Monascus purpureus Went (starch fungus) were affected by zinc. Zinc at concentrations of 2 × 10^-3M and 3 × 10^-3M nearly stopped the growth, pigmentation and antibiotic production of both wild type and strain NI IS in liquid medium. Relatively vigorous growth, high pigment production, and strong antibacterial activity of NIIS still occurred on solid medium with the same zinc concentrations. Wild type was hardly affected by zinc concentrations lower than 2 × 10^-3M. The growth of strain NI IS was significantly inhibited even by 5 × 10^-5M zinc, but pigment production and antibacterial activity were highly promoted by 5 × 10^-5M zinc. Increase of glucose concentration also promoted pigment and antibiotic productions of strain NI IS. Glucose effects were intensified as 1 × 10^-3M zinc was added. Zinc may act as a growth inhibitor and concomitantly as a stimulant for glucose uptake and for the synthesis of metabolites such as pigments and antibiotics.     

Control of Ophiobolus patch in Agrostis turf using avirulent fungi and take-all suppressive soils in pot experiments

The incorporation of avirulent fungi such as Gaeumannomyces graminis var. graminis, an avirulent isolate of G. graminis var. tritici, a Phialophora sp. with lobed hyphopodia synonymous with Phialophora radiciola var. radicicola sensu Deacon and P. radicicola var. graminicola at the time of seeding Agrostis turf in pots of sterilised soil completely controlled Ophiobolus patch disease. The addition of a 5 mm layer of take-all suppressive (TAS) soils, artifically developed by the repeated addition of live mycelium of the varieties avenae, tritici and graminis of G. graminis to soil, controlled the disease to a lesser extent. However, a 20 mm layer of a TAS soil developed from live mycelium of G. g. avenae almost completely suppressed the disease. A survey of 66 golf and bowling greens in four states of Australia showed that P. r. graminicola was the most prevalent avirulent fungus.     

Mitochondrial gene order is not conserved in arthropods: prostriate and metastriate tick mitochondrial genomes

The entire mitochondrial genome was sequenced in a prostriate tick, Ixodes hexagonus, and a metastriate tick, Rhipicephalus sanguineus. Both genomes encode 22 tRNAs, 13 proteins, and two ribosomal RNAs. Prostriate ticks are basal members of Ixodidae and have the same gene order as Limulus polyphemus. In contrast, in R. sanguineus, a block of genes encoding NADH dehydrogenase subunit 1 (ND1), tRNA(Leu)(UUR), tRNA(Leu)(CUN), 16S rDNA, tRNA(Val), 12S rDNA, the control region, and the tRNA(Ile) and tRNA(Gln) have translocated to a position between the tRNA(Glu) and tRNA(Phe) genes. The tRNA(Cys) gene has translocated between the control region and the tRNA(Met) gene, and the tRNA(Leu)(CUN) gene has translocated between the tRNA(Ser)(UCN) gene and the control region. Furthermore, the control region is duplicated, and both copies undergo concerted evolution. Primers that flank these rearrangements confirm that this gene order is conserved in all metastriate ticks examined. Correspondence analysis of amino acid and codon use in the two ticks and in nine other arthropod mitochondrial genomes indicate a strong bias in R. sanguineus towards amino acids encoded by AT-rich codons.      

Nucleotide polymorphism at the alcohol dehydrogenase locus of pocket gophers, genus Geomys

Using the strictly neutral model as a null hypothesis, we tested for deviations from expected levels of nucleotide polymorphism at the alcohol dehydrogenase locus (Adh-1) within and among four species of pocket gophers (Geomys bursarius major, G. knoxjonesi, G. texensis llanensis, and G. attwateri). The complete protein-encoding region was examined, and 10 unique alleles, representing both electromorphic and cryptic alleles, were used to test hypotheses (e.g., the neutral model) concerning the maintenance of genetic variation. Nineteen variable sites were identified among the 10 alleles examined, including 9 segregating sites occurring in synonymous positions and 10 that were nonsynonymous. Several statistical methods, including those that test for within-species variation as well as those that examine variation within and among species, failed to reject the null hypothesis that variation (both within and between species of Geomys) at the Adh locus is consistent with the neutral theory. However, there was significant heterogeneity in the ratio of polymorphism to divergence across the gene, with polymorphisms clustered in the first half of the coding region and fixed differences clustered in the second half of the gene. Two alternative hypotheses are discussed as possible explanations for this heterogeneity: an old balanced polymorphism in the first half of the gene or a recent selective sweep in the second half of the gene.