115 research outputs found
Estimation of broad-leaved canopy growth in the urban forested area using multi-temporal airborne LiDAR datasets
Inter-annual canopy growth is one of the key indicators for assessing forest conditions, but the measurements require laborious field surveys. Up-to-date LiDAR remote sensing provides sufficient three-dimensional morphological information of the ground to monitor canopy heights on a broad scale. Thus, we attempted to use multi-temporal airborne LiDAR datasets in the estimation of vertical canopy growth, across various types of broad-leaved trees in a large urban park.
The growth of broad-leaved canopies in the EXPO '70 urban forest in Osaka, Japan was assessed with 19 plots at the stand level and 39 selected trees at the individual-tree level. Airborne LiDAR campaigns repeatedly observed the park in the summers of 2004, 2008, and 2010. We acquired canopy height models (CHMs) for each year from the height values of the uppermost laser returns at every 0.5 m grid. The annual canopy growth was calculated by the differences in CHMs and validated with the annual changes in field-measured basal areas and tree heights.
LiDAR estimations revealed that the average annual canopy growth from 2004 to 2010 was 0.26 ± 0.11 m m−2 yr−1 at the plot level and 0.26 ± 0.10 m m−2 yr−1 at the individual-tree level. This result showed that growing trends were consistent at different scales through 2004 to 2010 despite uncertainty in estimating short-term growth for small crown areas at the individual-tree level. This LiDAR-estimated canopy growth shows a moderate relation to field-measured increase of basal areas and average heights. The estimation uncertainties seem to result from the complex canopy structure and irregular crown shape of broad-leaved trees. Challenges still remain on how to incorporate the growth of understory trees, growth in the lateral direction, and gap dynamics inside the canopy, particularly in applying multi-temporal LiDAR datasets to the large-scale growth assessment
Relationships between the Use and Environment of an Unagi-nonedoko-like Green Space in Downtown Kyoto City
It is becoming necessary to consider the effective use of vacant lots that have developed due to the demolition of Kyo-machiya (traditional houses) in Kyoto. These long, narrow lots are called Unagi-no-nedoko (“beds of eel”). Their spatial characteristics might make them unsuitable as green spaces because there is the possibility of creating a dark, small, exclusive, and dangerous atmosphere. Thus, we investigated the influence of the environment of an Unagi–no-nedoko-like green space on user awareness and behavior. The results found that the inner area of the green space was as quiet as an indoor room and was recognized as a “relaxing” environment, which caused users to stay longer. Moreover, users found the whole area “large” and “open.” These findings demonstrate that the spatial characteristics of Unagi-no-nedoko do not necessarily make them uncomfortable as green spaces, and it is possible to use such lots as green spaces in downtown Kyoto
Characterizing the Historical Changes in Land Use and Landscape Spatial Pattern on the Oguraike Floodplain after the Meiji Period
Research on change in land use and landscape pattern is the foundation for studies exploring natural and cultural landscape of a region. This study used GIS software and utilized topographic maps to examine the changes that occurred in the Oguraike floodplain, during the time points of 1888, 1909, 1961, and 2002. The Oguraike floodplain, which was dominated by the landscape of Oguraike Pond and paddy fields in 1888, was dominated by the landscape of urban areas and paddy fields in 2002. Moreover, urban areas, cropland, paddy fields, and grasslands have become concentrated into larger patches, whilst the water bodies have become more fragmented. Overall, there has been a reduction in landscape diversity on the floodplain
Superwind-Driven Intense H_2 Emission in NGC 6240
We have performed a long-slit K band spectroscopic observation of the
luminous infrared galaxy NGC 6240. The peak position of the H_2 v=1-0 S(1)
emission in the slit is located ~0.3" - 0.4" north of the southern nucleus. It
is almost the midpoint between the southern nucleus and the peak position of
the ^12CO J=1-0 emission. Based on the line-ratio analyses, we suggest the
excitation mechanism of H_2 is pure thermal at most positions. In the southern
region we find the following three velocity components in the H_2 emission: the
blueshifted shell component (~-250 km s^-1 with respect to V_sys) which is
recognized as a distinct C-shape distortion in the velocity field around the
southern nucleus, the high-velocity blueshifted ``wing'' component (~-1000 km
s^-1 with respect to V_sys), and the component indicating possible line
splitting of ~500 km s^-1. The latter two components are extended to the south
from the southern nucleus. We show that the kinematic properties of these three
components can be reproduced by expanding motion of a shell-like structure
around the southern nucleus. The offset peak position of the H_2 emission can
be understood if we assume that the shell expanding to the north interacts with
the extragalactic molecular gas. At the interface between the shell and the
molecular gas concentration the cloud-crushing mechanism proposed by Cowie et
al. (1981) may work efficiently, and the intense H_2 emission is thus expected
there. All these findings lead us to propose a model that the most H_2 emission
is attributed to the shock excitation driven by the superwind activity of the
southern nucleus.Comment: 33 pages, 9 figures, accepted for publication in PAS
Changes in the Abundance of Monoterpenes from Breathable Air of a Mediterranean Conifer Forest: When Is the Best Time for a Human Healthy Leisure Activity?
The exposure to monoterpenes emitted by plants to the air might provide human health benefits during forest-based leisure activities. However, forests, especially Mediterranean ones, lack studies to relate forest production and the emission of monoterpenes, considering potential human forest exposure. Thus, the aim of this study was to analyze the variation in the abundance of monoterpenes in the human breathable air under the canopy of a Mediterranean conifer forest, evaluating the influence of different factors. For this purpose, from March to November 2018, we monitored the abundance of monoterpenes in the air at nose height, leaf development, air temperature and soil water potential in a mountain Mediterranean forest of Pinus pinaster located in Sierra de Albarracín (Teruel, Spain). We detected six monoterpenes, with a-pinene, ß-pinene and limonene being the three most abundant. Temperature was the main environmental factor driving the abundance of monoterpenes in air, with a maxima of abundance found during summer. Leaf development in spring decreased the abundance, while after a drought period, the abundance increased. Thus, people enjoying forest-based activities in Mediterranean conifer areas would be more exposed to air monoterpenes when the temperature increases during the period after leaf development, as long as the trees are not severely water-stressed. If that is the case, the abundance of monoterpenes in the air would increase after the drought period. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Current Performance and On-Going Improvements of the 8.2 m Subaru Telescope
An overview of the current status of the 8.2 m Subaru Telescope constructed
and operated at Mauna Kea, Hawaii, by the National Astronomical Observatory of
Japan is presented. The basic design concept and the verified performance of
the telescope system are described. Also given are the status of the instrument
package offered to the astronomical community, the status of operation, and
some of the future plans. The status of the telescope reported in a number of
SPIE papers as of the summer of 2002 are incorporated with some updates
included as of 2004 February. However, readers are encouraged to check the most
updated status of the telescope through the home page,
http://subarutelescope.org/index.html, and/or the direct contact with the
observatory staff.Comment: 18 pages (17 pages in published version), 29 figures (GIF format),
This is the version before the galley proo
Down-Sizing in Galaxy Formation at z~1 in the Subaru/XMM-Newton Deep Survey (SXDS)
We use the deep wide-field optical imaging data of the Subaru/XMM-Newton Deep
Survey (SXDS) to discuss the luminosity (mass) dependent galaxy colours down to
z'=25.0 (5 x 10^9 h_{70}^{-2} Msun) for z~1 galaxies in colour-selected high
density regions. We find an apparent absence of galaxies on the red
colour-magnitude sequence below z'~24.2, corresponding to ~M*+2 (~10^{10} Msun)
with respect to passively evolving galaxies at z~1. Galaxies brighter than
M*-0.5 (8 x 10^{10} Msun), however, are predominantly red passively evolving
systems, with few blue star forming galaxies at these magnitudes.
This apparent age gradient, where massive galaxies are dominated by old
stellar populations while less massive galaxies have more extended star
formation histories, supports the `down-sizing' idea where the mass of galaxies
hosting star formation decreases as the Universe ages. Combined with the lack
of evolution in the shape of the stellar mass function for massive galaxies
since at least z~1, it appears that galaxy formation processes (both star
formation and mass assembly) should have occurred in an accelerated way in
massive systems in high density regions, while these processes should have been
slower in smaller systems. This result provides an interesting challenge for
modern CDM-based galaxy formation theories which predict later formation epochs
of massive systems, commonly referred to as ``bottom-up''.Comment: proof corrected version (MNRAS in press), 10 pages, 12 figures (of
which 3 are in jpg format
Genome sequence of the tsetse fly (Glossina morsitans):Vector of African trypanosomiasis
Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa.
Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable
differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous
reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase
Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted
protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial
(Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of
host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These
genome data provide a foundation for research into trypanosomiasis prevention and yield important
insights with broad implications for multiple aspects of tsetse biology.IS
Seed dormancy and germination traits of an endangered aquatic plant species, Euryale ferox Salisb. (Nymphaeaceae)
Populations of Euryale ferox Salisb. have declined throughout its global range because of habitat loss and degradation. The present study aimed to evaluate the influence of storage temperature (4 and 20°C), storage period (0, 90, 180, 270, and 360 days), light condition (light and darkness), germination temperature (constant 10, 15, 20, 25, and 30°C), and seed size (two classes from 0.5 cm to less than 1.2 cm, and from 1.2 cm to less than 1.6 cm) on germination of E. ferox seeds. Our results indicated that seeds were dormant when shed and 4°C stratification promoted germination more effectively than 20°C. After stratification at 4°C, the germination frequency of the larger seeds peaked at 90 days’ stratification, whereas the smaller seeds maintained high germination frequencies up to 180 days’ stratification. The different germination responses between smaller and larger seeds may reflect a difference in the rate of induction of dormancy in the annual dormancy cycle. Seeds germinated in both light and darkness, which demonstrated that light is not involved in the regulation of E. ferox seed germination. The optimal temperature for germination was 25°C. Light condition × germination temperature interaction caused significantly higher germination frequency at 30°C in light than in darkness, and the opposite trend at 15°C
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