A Holocene record of climate change,fire ecology and human activity from montane Flat Top Bog,Maui

A sediment core from a high-elevation bog on Maui in the Hawaiian Islands contains evidence for drier conditions between 9.4–5.8 kyr BP, followed by a wetter interval between 5.8–2.2 kyr BP, and a variable late Holocene. These precipitation changes may be a reflection of vertical displacements of the upper boundary of the mid-Pacific Trade Wind Inversion (TWI) cloud layer. Fires, probably volcanically ignited, occurred in the forests prior to human arrival. Polynesian activity in this high-elevation, remote site was apparently limited, with no pollen, charcoal, or sedimentological evidence for local anthropogenic disturbance. After European contact, grass fires increased and introduced plant species invaded the site. Values for Cd, Cu, Pb, and Zn in sediments throughout the Holocene indicate low trace-metal deposition from atmospheric particulates at the site, even in the twentieth century.This paper is one of a series of papers guest edited by Dr. Mark Brenner on tropical paleolimnology     

A ‘mathematical’ spider living on gravel plains of the Namib Desert

In certain areas of the Namib gravel plains a new Ariadna sp. was discovered. It rims its vertical burrow with a stone circle, made on average of seven quartz stones. Some mathematical relationships between hole diameter, stone sizes and weight, and animal size were studied. A correlation was found, and stone selection by this spider postulated. Different hypotheses on the adaptive value of stone circle are suggested.     

Diurnal surface temperature difference index derived from ground-based meteorological measurements for assessment of moisture availability

Droughts have become widespread in the Northern Hemisphere, including in China, where they have affected farmland resources on the Loess Plateau. Given this background, we proposed a new index, the Normalized Day-Night Surface Temperature Index (NTDI), to estimate moisture availability (m_a), defined as the ratio of actual to reference evapotranspiration. The NTDI is defined as the ratio of the difference between the maximum daytime surface temperature and the minimum nighttime surface temperature, to the difference between the maximum and minimum surface temperatures estimated from meteorological data by applying energy balance equations.To calculate the index, we used data of 20 clear-sky meteorological observations made during the 2005 growing season at a natural grassland station in the Liudaogou River basin on the Loess Plateau. The NTDI showed a significant inverse exponential correlation with m_a (R² = 0.97, p < 0.001), whereas the numerator of the index (the maximum daytime surface temperature minus the minimum nighttime surface temperature) was only weakly correlated with m_a (R² = 0.24, p = 0.03). This result indicates that normalization relative to the index denominator (maximum surface temperature − minimum surface temperature) dramatically improved the accuracy of the estimate.     

Photoelectric device for monitoring the movement of a torsion balance beam

Manufactured and tested in his work is a photoelectric device that makes it possible to automatically determine the relative angular position of the beam of a miniature torsion balance, angular readings being discretized with various time step values and stored in a computer. Measurements were taken with this device that captured the occurrence of the partial solar eclipse on September 11, 2007, and confirmed the fact, established previously through visual observation, that the position of torsion balance beams changed at the instant an eclipse took place.     

The structure of benthic communities in an area of thermal discharge from a coastal power station

The area of sea subjected to heated effluent discharged from the power station at Piombino is very suitable for the study of problems connected with thermal pollution of the nearshore environment. Construction of the power station is planned to go ahead by successive operational stages, producing correspondingly increased amounts of heat discharged into the marine environment. At present it produces 640 MW and discharges 190 Mcal s^?1 into the sea.This paper studies the benthic communities after the power station had been operating for about 1 yr. Comparison of these data with those about subsequent operational stages will presumably allow to establish to what extent the environment can receive, without damage, increasing amounts of heat.     

INTEGRATION OF CARTOGRAPHIC AND REMOTE SENSING METHODS

The history of the joint use of maps and air photos/space imagery in geographic problem solving is examined, as are general problems which must be addressed before more complete consolidation of map use and image interpretation methods will be possible. The relatively new field of geoiconics, encompassing image theory, processing, and interpretation, is proposed as a branch of knowledge promoting the integration of cartography and remote sensing rather than a megafield that will ultimately replace them. Translated from: Geografiya i prirodnyye resursy, 1985, No. 4, pp. 11-22.     

Fossil insect evidence for late pleistocene paleoenvironments of the lamb spring site,Colorado

The study of Quarternary insect fossils has shown their value as paleoenvironmental indicators, especially during times of rapid climatic change, and this method is now being introduced into North America archeological studies. Abundant insect fossils have been recovered from 13,000 year old detrital organic materials from silty clays at the Lamb Spring site, south of Denver, Colorado. The spring deposits also contain bones of extinct camel and mammoth, thought to have been modified by human hunters. The late Pleistocene insect fauna from Lamb Spring comprises 71 identified taxa from 6 orders and 14 families, principally beetles, providing substantial paleoenvironmental data. The beetle fauna is a mixture of grassland and mountain elements, and they appear to represent an environment similar to that found today in high mountain valleys, such as South Park, Colorado. Based on this fauna, mean summer temperatures at 13,140 B.P. were probably 10°C cooler than present.     

The Velocity Field and Kinematics of the Galaxy NGC 784 in the Hα Line

In this paper we present the H map, the 2D velocity field and the rotation curve of the galaxy NGC 784 obtained with the ByuFOSC2 scanning Fabry-Perot interferometer, attached at the prime focus of the 2.6-m telescope of Byurakan Observatory. The H image shows several HII condensations along the major axis of the galaxy. The galaxy has an asymmetric distribution of the H emission. The rotation curve is quite symmetric with a low gradient in the central part of the galaxy.     

A New Protocol for the Astrometric Follow-up of Near Earth Asteroids

A new protocol was devised to improve the efficiency of astrometric follow-up observations of Near Earth Asteroids for the accurate determination of their orbits. It was implemented in the activities of the Spaceguard Central Node (SCN, a facility of the Spaceguard Foundation, established with the support of the European Space Agency) in the form of a Priority List. Here we describe this protocol and results obtained during five years of activity (2000–2004).     

LATE QUATERNARY CHANGES IN PINYON AND JUNIPER DISTRIBUTIONS IN THE WHITE MOUNTAIN REGION OF CALIFORNIA AND NEVADA

Data from packrat middens are used to reconstruct the migration of single-leaf pinyon (Pinus monophylla) and Utah juniper (Juniperus osteosperma) in the White Mountain region of California and Nevada for the last 20,000 years. Today this region is characterized by arid conditions with dry summers. Pinyon woodlands, which are favored by dry summer conditions, are dominant at middle elevations of the White Mountains. The midden record indicates that during the late Pleistocene and early Holocene, juniper was dominant at elevations now occupied by desert shrubs. A late Pleistocene-early Holocene record of desert shrubs was found only in the double rainshadow of the Sierra Nevada and the White Mountains. Pinyon entered the area during the Holocene (ca. 9000 yr B.P.) and subsequently became more important than juniper. During the late Holocene, desert shrubs became established at the lower elevation sites that they now occupy. The late Pleistocene-early Holocene record indicates that there may have been a more zonal upper-level wind flow and associated penetration of Pacific moisture, as indicated by the occurrence of desert shrubs downwind of the north-south-trending mountain ranges. Zonal flow probably became less important during the early Holocene based on the increasing amount of pinyon. The increase in pinyon also may indicate a change from an even seasonal distribution of precipitation to the dry summer conditions presently found in the region. [Key words: biogeography, packrat middens, Great Basin paleoenvironments, Pinus monophylla, Juniperus osteosperma, White Mountains.]