LiDAR with Pulsed Time of Flight

LIDAR data has proved useful in recent years since it gives information such as item height and attributes, statistics over large regions, and it all becomes available by capturing the intensity of backscattered pulses in addition to 3D coordinates. “A LiDAR may generate a 2D angle image as well as a 3D picture containing angle/angle/range information. A LiDAR can directly measure range in each pixel since it controls when light is emitted, allowing it to calculate range based on the time of flight (ToF) to and from the object in a particular pixel. If there is enough signal, a 3D picture can also have grayscale and colour”. Coherent LiDAR can detect velocity quite precisely. Brief descriptions of airborne laser scanning technology [also known as "light detection and ranging" (LIDAR)] and research findings on its application in forest assessment and monitoring are included. Many airborne laser scanning missions are being flown with terrain mapping requirements, leading to data sets that are missing important data for vegetation evaluation. As a result, standards and criteria for airborne laser scanning missions are needed to guarantee that they are used for vegetation measurement and monitoring instead of merely landscape mapping (e.g., delivery of all return data with reflection intensity).

Short Communication: A comparison of stand structure, species diversity and aboveground biomass between natural and planted mangroves in Sikka, East Nusa Tenggara, Indonesia

Matatula J, Afandi AY, Wirabuana PYAP. 2021. Short Communication: A comparison of stand structure, species diversity and aboveground biomass between natural and planted mangroves in Sikka, East Nusa Tenggara, Indonesia. Biodiversitas 22: 1098-1103. The effectiveness of mangroves reforestation can be evaluated by comparing the stand dynamics of planted mangroves with natural mangroves in similar site conditions. This study investigated stand structure, species diversity and aboveground biomass between natural and planted mangroves in Sikka, East Nusa Tenggara. A field survey was conducted using quadrat transect method for vegetation measurement, especially related to species composition and its size distribution. Several parameters were recorded in field observation, including number of species, diameter, height, volume, and aboveground biomass. The stand structure of both mangroves was demonstrated by the distribution of diameter class while the species diversity was described using three parameters, i.e., richness, heterogeneity, and evenness. Moreover, the IVI of each species recorded was also calculated to understand the contribution of species in the mangrove ecosystems. The comparison of stand characteristics between natural and planted mangroves was examined by Mann-Whitney test and Spearman Correlation was also applied to understand the relationship between IVI and aboveground biomass. The results showed that the diameter and height between the natural and planted mangroves significantly differed (P<0.05). In contrast, there was no significant difference in tree density, volume, and aboveground biomass (P<0.05). The stand structure of both mangrove stands followed the pattern of J-inverse in which the frequency of trees decreased with the increase in diameter class. Species diversity in both stands was statistically equal in richness, heterogeneity, and evenness (P>0.05) even though there were some specific species which only observed in the natural or planted mangroves. The most superior species in the planted mangroves was Rhizophora mucronata (IVI = 96.99) while the most important plant in the natural mangroves was Sonneratia alba (IVI = 82.49). Our study found there was a significant correlation between IVI and aboveground biomass in which species with higher IVI indicated greater aboveground biomass. Based on these findings, restoration efforts of degraded mangroves in Sikka have been effective. The restoration, which has been conducted for almost three decades, has not only brought back its vegetation cover but also the functional traits of the mangrove stand to mimic with natural mangroves in the area.

POTENSI VEGETASI SEBAGAI PEREDAM INGAR BUNYI KENDARAAN BERMOTOR

The increases of transportation everyday have made multiple effects especially for human heal th. Based on the effects appeared by noise, there were three steps could be done to prevent, to reduce, or to control it. First, noise control at the source of noise, second, noise control at the line, and third, noise control for the receiver (human). This research focus on noise control at the source of noise by plants. The purpose of this research was to investigate the traffic noise attenuation by vegetation. The noise was measured with Sound Level Meter and was taken at two areas, control area without vegetation and deal area with vegetation. Measurement was done in busy days and weekday in the morning, midday, and afternoon. The measurement repeated as many as three. The observation showed that the traffic noise in control area ranging from 77.3 -79.4 dBA, whereas in deal area traffic noise ranging from 56.3-59.4 dBA. In this case, vegetation could reduce the traffic noise as many as 20-21 dBA although the observation result over quality standard which defined by The Ministry of Environment no. 48/1996, that was 65 dBA for office and commerce (control area), and 55 dBA for housing and settlement (deal area).