Comparison of cavity modification and community involvement as strategies for hornbill conservation in Thailand

We monitored breeding success of hornbills in Thailand for four sympatric species at Khao Yai National Park during 1981-2002 and six species at Budo-Sungai Padi National Park during 1994-2002. Within a 60 km² study area at Khao Yai, the well protected area, use of available cavities ranged from 94% in 1984 to 50% in 1993. Competition for nesting cavities was 40% of cavities available indicating the shortage of suitable cavity. We monitored the cavity condition and modified 48 cavities and, between 1996 and 2000, these contributed annually 23-45% of nestings that were successfully fledged (n = 352). Within the 90 km² at Budo Mountain, with heavy human disturbance, use of available cavities for nesting decreased from 81% in 1997 to 30% by 2001 and of successful fledging from 96% in 1997 to 55% in 1999, but both increased once our involvement with local communities had eradicated poaching and reduced disturbance. Competition for nesting cavities here was 26% of cavities available indicating the effect of poaching. Both strategies were successful in the short term but long-term management of cavities in large forest trees is required at Khao Yai and of forest disturbance at Budo.     

烤烟根际微生物群落结构及其动态变化的研究

选择贵州省三种典型的植烟土壤———中性紫色土、黄壤和黄色石灰土为对象,研究了烤烟根际微生物群落结构及其动态变化。结果表明,在烤烟生长过程中,根际细菌的数量在团棵期最低,然后逐渐增加,现蕾期达到峰值,进而又逐渐减少;放线菌和真菌数量从团棵期到成熟期呈增长趋势。土壤类型不同,根际细菌和放线菌的数量不一样,黄壤>黄色石灰土>中性紫色土;真菌数量,中性紫色土>黄壤>黄色石灰土。烤烟根际微生物的种群多样性及其变化在不同土壤中表现也不一样,相对于黄壤和黄色石灰土,在中性紫色土中,根际微生物的优势种群数目较多,根际细菌和放线菌种群更具多样性,而且较稳定,表明其群落结构更为合理,这可能与中性紫色土上的烟草青枯病发生率较低有一定关系。     

氮、磷、钾肥对丹参根系生长及养分含量的影响

采用田间小区试验方法,研究了氮、磷、钾肥对丹参根系生长及养分含量的影响。结果表明,氮、磷、钾肥能够促进丹参根系对氮、磷、钾的吸收,提高其含量,并且随着施用量的增加而提高,在N,P2O5,K2O的施用量分别为225,180,225 kg/hm2时,根的氮、磷、钾含量达到最高值;当施入N,P2O5和K2O分别为225,120,150 kg/hm2时,丹参根干质量、根长及根条数达到最高值,根的直径最适宜,此后随着磷钾肥施入量增加,根干质量及根长、根条数反而下降,根直径增加。所以氮、磷、钾合理配合施用能够提高丹参根的养分含量、根干质量、根长、根数及根直径。     

高砷硫铁矿周边农田土壤砷分布及真菌群落结构特征研究

本文主要以高砷硫铁矿区周边农田中的真菌群落为研究对象,研究利用Miseq高通量测序技术系统的分析了矿区周边不同区域土壤中真菌的群落特征,对硫铁矿区周边土壤真菌群落的适应机制进行了探究分析。结果表明,(1)砷、铁复合污染土壤可促使土壤真菌丰富度降低,而对土壤真菌多样的影响则表现为先促进后抑制;(2)砷、铁复合污染抑制土壤中Ascomycota(子囊菌门)代谢,促进Basidiomycota(担子菌门)代谢,而对Zygomycota(接合菌门)则表现为低浓度促进,高浓度抑制,对Fusarium(镰刀菌属)、Pseudallescheria(假霉样真菌属)、Cryptococcus(隐球菌属)也呈现“低浓度促进、高浓度抑制”作用;(3)砷、铁的复合物污染使土壤中真菌群落结构产生了明显差异,环境因子对土壤环境真菌群落结构差异影响大小依次为有效砷、总砷、总铁。     

菜心的土壤钙、镁营养诊断指标及施肥效应研究

在不同地方,不同钙、镁含量水平的菜园土壤进行菜心钙、镁肥田间试验。根据20个试验点的钙肥试验和15个试验点的镁肥试验结果,分别建立菜心相对产量与土壤交换性钙、镁含量的回归方程。研究结果表明:菜心产量与土壤交换性钙、镁含量分别呈抛物线相关;在质地为中壤土的菜田上种植菜心,土壤交换性钙的适宜含量为4.26￣9.60cmolL-1,交换性镁的适宜含量为2.01￣2.31cmolL-1;在参试的所有菜田中,施钙肥增产显著的菜田占50%,增产率为0.65￣33.8%;施镁肥增产显著的菜田占47%,增产率为-1.6%￣34.7%。     

Starving the soil of plant inputs for 50 years reduces abundance but not diversity of soil bacterial communities

If soil communities rely on plant-derived carbon, is biodiversity lost when this primary source is removed? Soil microbial and mesofaunal communities at the Rothamsted Highfield site were compared under a mixed grass sward, arable rotation and a section maintained as a bare-fallow for the past 50 years by regular tillage. Organic matter reserves have been degraded and microbial and mesofaunal numbers and mite diversity have declined in this unique bare-fallow site, where fresh carbon inputs have been drastically reduced. However, it supports a species-rich metabolically active bacterial community of similar diversity to that in soil maintained as grass sward. Thus in contrast to soil mesofauna, bacterial diversity (but not abundance) is apparently independent of plant inputs.     

苏打盐渍土地区芦苇地土壤盐分离子空间变异与群落关系研究

对松嫩平原西部苏打盐渍土地区芦苇小区土壤盐分离子和植被群落进行了分析,结果表明土壤盐分离子空间变异显著,四种阳离子(Na+、K+、Ca2+、Mg2+)变异系数为0.60~1.22,四种阴离子(HCO3-、CO32-、C l-、SO42-)变异系数为0.35~1.41。离子中,Na+在阳离子中含量最高,HCO3-在阴离子中含量最高。群落间比较,碱茅+芦苇群落八大离子浓度均大于芦苇群落(p<0.05)。且土壤电导率、pH,以及株高、生物量、覆盖度也高于芦苇群落(p<0.01),因此随着土壤电导率、离子浓度的增加,芦苇小区土壤碱化程度加重,植被生长指标减小,植被群落也由芦苇群落向含有碱地植被的碱茅+芦苇群落过渡。     

不同营养条件下氟对小鼠肝肾及心肌的影响

将64只昆明鼠分为4组,分别给以0,25,50,100mgF／L的饮水,每组动物再分为两小组,设一个低营养组,一个高营养组,以比较相同饮水氟于不同营养条件下肝、肾及心肌的损伤情况。结果表明,在给氟90d时,50及100mgF／L组动物的肝脏可见脂肪及水泡变性,肾脏皮质肾小管上皮可见水泡变性,心肌纤维着色不匀,个别纤维可见颗粒变性。相同氟水平下不同营养组间比较,高营养组上述变化明显减轻,表明补充营养可以缓减氟对软组织的损伤。     

三个天然次生林群落中主要树木种群间联结关系的研究

通过对三个天然次生林群落中几个主要树木种群的ＲＡ、ＲＤ、ＲＦ及ＩＶ值的比较分析以及种间联结系数（ＡＣ）的求算，研究了各主要树木种群间的相互关系，并通过种间联结星座图（ｃｏｎｓｔｅｌｌａｔｉｏｎｇｒａｐｈ）对此种关系作了直观反映．研究结果对于深入分析天然次生林群落结构形成的内在机制及其动态特征具有重生意义．     

沾河林区夏季森林鸟类群落结构研究

1990年5—6月在黑龙江省沾河林业局,通过路线调查法研究了该地区夏季森林鸟类群落的结构,旨在揭示鸟类群落的物种多样性在空间上的变化模式以及它与物种生态位的关系。研究结果表明,该地区不同鸟类群落的物种多样性的排列顺序为针阔混交林>阔叶林>灌丛>针叶林。鸟类群落的物种多样性存在着垂直变化。也随栖位而改变,并且这些变化在各鸟类群落中表现出不同的模式,在不同的鸟类群落中,5种常见鸟类(灰头鹀、大山雀、沼泽山雀、黄腰柳莺、黑眉苇莺)有不同的生态位宽度和生态位重叠。鸟类群落的物种多样性与群落中各物种生态位的平均宽度和重叠存在一定的相关关系。