Estimating bird species richness: How should repeat surveys be organized in time?

Abstract Estimates of species richness for a given area require that repeat surveys be taken, so that the statistical robustness of the estimate can be assessed. But how should these repeat surveys be organized in time? Here we present a case study of Australian woodland birds, surveyed using the ‘active timed area search’ method, which has become the standard unit for the Australian Bird Atlas, a continental‐scale bird survey. To date, there has been no assessment of how estimates of species richness derived from this method are affected by the temporal organization of the repeat surveys. For instance, can conducting the repeat surveys in sequence on the same day effectively capture richness, or will additional species be obtained by repeating the surveys on different days within a season? If so, does the spacing of the repeat visits throughout the season have an effect? To answer these questions, we surveyed woodland birds in the Mount Lofty Ranges, South Australia, during late spring–summer 1999–2000, and compared the performance of two different temporal configurations of repeat visits to sites: (i) six repeat surveys performed on the same day; and (ii) three repeat surveys on different days. For both, we calculated the average number of species actually sighted and also estimated total species richness. The data supported our hypothesis that the same‐day surveys would yield fewer species and underestimate total species richness. The different‐day repeats captured significantly more species per unit of survey effort, and yielded a higher richness estimate. However, the timespan over which different‐day surveys were conducted within a season did not have a significant influence on species richness estimates, evincing a qualitative advantage to surveying on different days, regardless of the spacing of repeat visits. These results may be of assistance to conservation managers when planning cost‐efficient monitoring regimes.     

利用红外相机技术对九连山国家级自然保护区兽类和鸟类资源的初步调查

九连山国家级自然保护区是我国中亚热带与南亚热带常绿阔叶林的过渡地带,动植物种类丰富多样。为进一步掌握该保护区野生动物资源现状,我们于2014年11月至2015年7月在保护区布设了31个红外相机监测点,对大中型兽类和林下活动鸟类进行了初步摸底调查。相机累计工作4 692个捕获日,共获得有动物的独立有效照片3 341张,鉴定出鸟兽物种共10目16科33种（兽类12种,鸟类21种）。属于国家Ⅱ级重点保护动物有斑灵狸（Prionodon pardicolor）、白鹇（Lophura nycthemera）和灰脸鵟鹰（Butastur indicus）等。兽类以赤腹松鼠（Callosciurus erythraeus）、白腹鼠种类（Niviventer rats）、小泡巨鼠（Leopoldamys edwardsi）和倭松鼠（Tamiops maritimus）等物种的相对丰富度指数较高。相对丰富度指数较高的鸟类物种依次为白鹇、紫啸鸫（Myophonus caeruleus）和黑领噪鹛（Garrulax pectoralis）等。结合以往记录,灰头绿啄木鸟（Picus canus）、乌灰鸫（Turdus cardis）、绿翅金鸠（Chalcophaps indica）、白眉鸫（Turdus obscurus）和白冠燕尾（Enicurus leschenaulti）等为保护区的鸟类新记录种。本研究的调查结果为进一步在九连山自然保护区开展鸟兽资源的长期监测奠定了基础。     

Geographical information system-based forest fire risk assessment integrating national forest inventory data and analysis of its spatiotemporal variability

Improvements in forest fire risk estimation and mapping fire risk zones are vital to reduce the negative impacts of fire and to facilitate planning for the protection of forested areas. This is especially important for places with little previous data on fire history. This paper presents an improved conceptual scheme for the assessment and mapping of fire risk using a Forest Resource Inventory Database, based on four aspects of topographical, human activity, climate, and forest characteristics factors. We selected 12 variables based on our defined conceptual scheme to generate a synthetic forest fire risk index (FRI) to quantify potential forest fire risk and map risk zones in the Wuyishan Scenery District (WSD), a world heritage site that located in the northwest of Fujian province, People's Republic of China. Spatial statistics were used to examine the spatio-temporal variation of FRI. The results showed the main fire risk zones in the WSD were in the low or moderate categories (accounting for 76.7% of the total area of the WSD in 1997 and 79.2% in 2009). The spatial heterogeneity of FRI showed anisotropic variability characteristics which changed over time. From 1997 to 2009, there was an increasing influence from both autocorrelation factors and random factors. Moreover, these factors played almost equally important roles in forest fire processes in the WSD. The fire risk map was applied to assess the vulnerability of cultural heritage resources in the WSD. Most were located in low- or moderate-risk areas, and therefore would be at low risk from potential fire damage.     

Species properties and recovery from disturbance: Forest herbs buried by volcanic tephra

Question: How do forest herb species differ from each other in their spatial and temporal dynamics during recovery from volcanic disturbance, and how are dynamics related to species traits? Location: Northeast of Mount St. Helens, Washington, USA. Methods: Following deposition of volcanic tephra in 1980, we measured herb density and cover in permanent 1‐m² plots during 1980‐2005 in three old‐growth forests with differing tephra depths. For 26 species, we calculated the frequency of plots with residuals (individuals that survived the eruption) versus re‐establishment on the tephra, timing of establishment, turnover, influence of nearby conspecific plants, importance of three components of cover increase, and relationship of flowering frequency to succession. Results: Tephra depth affected species behavior. Deep tephra produced fewer residuals, a greater increase in shoot size, and more shoot turnover; favored species that established late; and allowed establishment of early seral herbs. Nearby presence of conspecifics increased permanence of first establishment and rate of plot occupancy. Most species spread significantly in deep tephra but not in shallow tephra. Among species, frequency of flowering increased with fewer residuals, later establishment, and higher turnover. Species behavior seldom differed among growth forms based on leaf longevity and vegetative spread. Conclusion: Population dynamics at the small‐plot scale differed from those of the entire population. The timing and permanency of establishment and mechanism of expansion differed among species and with tephra depth. There was some consistency among species with similar habitat breadth and degree of flowering, but little consistency associated with the usual growth form classification.     

深圳马峦山珍稀濒危植物及其群落特征

在调查基础上,对深圳马峦山地区的珍稀濒危植物及石笔木、白桂木和樟树3个群落特征进行了分析,并探讨了其保护对策.结果表明:(1)该区有36种珍稀濒危植物,分别属于9科20属,其中,蕨类植物2科2属2种,裸子植物1科1属1种,被子植物6科27属33种;C2)群落多样性指数,SW在4.19～4.98之间,E'在0.76～0....     

江西南风面濒危植物资源冷杉生存状况及所在群落特征

资源冷杉是国家一级保护植物、中国特有种,呈极度濒危状态。采用样地调查法对江西南风面无人为干扰的原始森林资源冷杉所在群落特征进行研究,结果表明:调查群落共有维管植物68种,隶属34科47属; 含属种较多的科有杜鹃花科(2属8种)、山茶科(4属6种)、冬青科(1属6种)、樟科(2属5种)、壳斗科(3属4种),占总种数的42.0%; 热带性质的属共占非世界属总数的46.5%,温带性质的属共占48.8%,中国特有分布的属占4.7%; 古老的残遗属和亚热带山地的表征属占有极大的优势。群落乔木层可分为4层,第一亚层和第二亚层的优势种有资源冷杉、南方铁杉、南方红豆杉和多脉青冈等。调查的资源冷杉种群目前处于相对稳定的状态,所在群落是该地区的顶极群落。     

峨眉山区野生濒危药用植物资源评价体系的初步研究

峨眉山区属于亚热带季风气候区,野生药用植物资源十分丰富。经过三年的野外调查和文献资料整理,首次建立了峨眉山以蕴藏系数、保护缓急程度等7项指标在内的定量评价濒危药用植物指标体系。结果表明:峨眉山目前1655种野生药用植物(含变种、变型)中,受到生存威胁的药用植物种类共56科102属152种。其中急需保护的有19科29属41种,分别占其科属种数的33.93%、28.43%和26.97%,代表种类主要有峨眉金线兰、峨眉黄连、峨眉拟单性木兰、峨眉岩白菜等;需要保护的有22科,29属,35种,分别占其科属种的39.29%、28.43%和23.02%,代表种类主要有四川木莲、峨眉荚蒾、峨眉忍冬、峨眉雪胆等;一般保护的有41科59属76种,分别占其科属种的73.21%、57.84%和50%,代表种类主要有黄连、川桂、八角莲、威灵仙等。     

The regulatory framework for the exploitation of medicinal plants in Cameroon: the case of Prunus africana on Mount Cameroon

Before the beginning of its large scale exploitation by a European pharmaceutical company in 1972, the tree species Prunus africana was known in Cameroon only for traditional uses. The present exploitation may lead to its extinction on Mount Cameroon. This paper explains the destruction of P. africana within the current regulatory framework and recommends stricter compliance with the regulations, which would guarantee survival of this species in the wild. Field observations are also presented.