1. Chronosequence of Natural Regeneration in Abandoned Mining Sites in the Amazon Rainforest of Madre De Dios, Peru
Edson J. MORALES-PARRA1,2*, Nobuyiki TANAKA1, Martin PILLACA3, Francisco ROMÁN-DAÑOBEYTIA3,4 Luis E. FERNANDEZ 3,4 and Miles SILMAN 3,4
1Department of International Agricultural Development, Tokyo University of Agriculture, Tokyo, Japan
2Amazonian Scientific Innovation Center (CINCIA), Madre de Dios, Peru
3Geographic Information Systems Department, Amazonian Scientific Innovation Center (CINCIA), Madre de Dios, Peru
4Center for Energy, Environment and Sustainability and Department of Biology, Wake Forest University, NC 27106, USA
Abstract: Gold extraction via small scale mining in the Amazon rainforest of Peru has become one of the greatest threats to deforestation and land degradation in the Amazon, especially in the Madre de Dios region which is one of the last biggest remnants of continuous tropical rainforest in the world. Restoration of these degraded ecosystems have become a priority in the last decade but without concrete actions, however, few research has been conducted in response to these restoration activities nor natural regeneration. The significance of this research was to study a chronosequence of natural regeneration in two active gold-mining sites in Madre de Dios-Peru (Paolita-PA; Santa Rita-ST) and how the nearby remnant forest contribute to natural regeneration. Sites were chosen depending on its management and the proximity to nearby remnant forest. Floristic composition of natural regeneration following abandonment of mining activities was studied by establishing a total of 12 plots (20x50m each), 6 with an abandonment period of 2 to 16 years and 6 were considered as reference forest. A total of 753 individuals from 44 families and 144 species were identified. To analyze biodiversity and similarity composition, Shannon and Jaccard indexes were used, respectively. The results showed that the abundance of species (Shannon) was higher in Paolita than in the Santa Rita mining site. From Jaccard’s similarity index each mining site was analyzed in clusters finding that in Paolita, nearby remnant forest might not have a great influence over natural regeneration when compared with Santa Rita site which showed similarity between remnant forest, but instead the time of abandonment, availability of nutrients and forest fragmentation might be the cause of the recovery of degraded forest.
Keywords: Chronosequence, Natural regeneration, Gold mining, Amazon rainforest, Peru.
Pages: 111 – 120 | Full PDF Paper
Aeron M.A. Nahuku1, Kelvin Tembo2, Flemings Ngwira3, Estiner Katengeza4, Doreen Mdzeka Nahuku5
1. Biomedical Sciences Department,College of Medicine, University of Malawi, Mahat Ma Ghandi Road, P/Bag 360,Chichiri, Blantyre, Malawi.
2. Centre for Water, Sanitation, Hygiene and Appropriate Technology Development, The Polytechnic, University of Malawi, P/Bag 303, Chichiri, Blantyre, Malawi.
3. Department of Language and Communications, The Polytechnic, University of Malawi, Blantyre, Malawi.
4. Department of Physics and Biochemical Sciences, The Polytechnic, University of Malawi, P/Bag 303, Blantyre, Malawi.
5. The Polytechnic, University of Malawi, Blantyre, Malawi.
The associated potential health threatening effects of Radiofrequency (RF) radiation are highly debatable among scholars and science experts with emphasis on those originating from mobile phone base stations (BTS). On one hand, the population of these BTSs has increased globally and Malawi in particular. City locations have generally larger number of users and also obstructions which in compensation, allows a lot more BTSs to cover demand with possible cell sizes of about 2-5km radius or less. EM and RF fields are classified as carcinogenic in nature with others being sleeping problems, fertility problems, chromosome alterations, dizziness as well as nausea as detrimental health problems associated with BTSs.
In order to evaluate the measured radiation levels from the BTS, the study employed a descriptive study design where a Spectran HF V4 spectrum analyser was used to measure RF radiation levels in Watts per square meter (W.m-2) at every 25m interval from the fence of the BTS to a maximum distance of 150m. Quantitative data management used Microsoft excel and IBM® SPSS® statistics version 23.0 for organization and analysis to further answer the research question(s)
A total of 17 BTSs in Lilongwe were purposively selected and their RF radiation levels at different distances from the BTS fence was measured and analysed. The investigation registered a maximum radiation level of 0.00139W.m-2. All the recordings were found to be below the ICNIRP standard guidelines of 1 – 10W.m-2 and safe for the public.
When compared to other epidemiological studies, similar radiation levels were reportedly linked with other public health concerns in the literature. It is important to consider roof top BTSs as well as street mounted towers in similar studies in the future and intensify on number of base station measurements. Civic educating the public on better safety aspects on such EM and RF radiation sources could be commendable while on one hand making the information available.
Keywords: Base stations, Ionizing Radiation (IR), Non-Ionizing Radiation (NIR) Radiofrequency (RF) radiation, Specific Absorption Rate (SAR), Power density, ICNIRP guidelines.
Pages: 121 – 134 | Full PDF Paper
Vazha Todua1, Otari Chitanava2
1. Botanic-Zoology Department, Sokhumi State University, 9 Politkovskaya Str., 0186, Tbilisi, Georgia.
2. Georgian Technical University, 77, Kostava Str., 0160, Tbilisi, Georgia.
The article presents a description of the plant sequoia that grows in the Zugdidi Botanical Garden of the Samegrelo region in Georgia. The Megrelian sequoia is compared to the sequoia collection in California. It is characterized by the nature of Samegrelo and the Poti lowland, which is comparable to the nature of California. Economic gains and links with other countries are also shown.
The article was written in August 2019.
Keywords: Flora, Megrelian, Kolkheti, Botanical garden, Zugdidi, Sequoia, Poti.
Pages: 135 – 141 | Full PDF Paper
4. Changes in Wood Tree Species Fagus sylvatica L. and Characteristics of the Thermal Process of Modifying Its color with Saturated Water Steam
Ladislav Dzurenda, Michal Dudiak
Faculty of Wood Sciences and Technology, Technical University in Zvolen, 960 53 Zvolen, Slovakia.
The aim of this work is to present changes in beech wood acquired in the targeted process of color modification of sapwood and mature beech wood with saturated water steam with temperatures tI = 105 ± 2.5 °C for τ = 6 hours. (Mode I), tII = 127.5 ± 2.5 °C for τ = 6.5 hours (Mode II), tIII = 137.5 ± 2.5 °C for τ = 7 hours (Mode III), and also to present characteristics of the technological process in terms of heat and saturated steam consumption.
On the basis of experimental work and subsequent analyzes, for individual modes of thermal modification of beech wood color by water steam, the following are determined:
– the density of thermally treated beech wood with saturated steam,
– the acidity of thermally treated beech wood with saturated steam,
– coordinates of lightness L*, red color a* and yellow color b* of thermally treated beech wood in CIE L* a* b* color space,
– heat consumption per 1 m3 of thermal modification of beech wood color with water steam, consumption of saturated water steam per 1 m3 of thermal modification of beech wood color with saturated water steam.
Keywords: beech wood, the CIE-L*a*b*colour space, thermal treatment, saturated water steam, technical and technological parameters.
Pages: 142 – 156 | Full PDF Paper