scholarly journals Biological recovery the steppe of Hammada scoparia after enclosure in the region of Naama (Algeria)

2017 ◽  
Vol 36 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Hafidha Boucherit ◽  
Kheloufi Benabdeli ◽  
Abdelkrim Benaradj
Keyword(s):  
Plant Diversity ◽  
Natural Regeneration ◽  
Production Potential ◽  
Biological Recovery ◽  
Inverse Process ◽  
Steppe Vegetation ◽  
The Past ◽  
Intervention Measures ◽  
Continued Use

Abstract This work was being carried out in the steppe of remth (Hammada scoparia) in Oranian part of the Saharan Atlas (Tiout - south of Naama). The H. scoparia of Saharan group occupies the foothills south of the Saharan Atlas and glazes and hamadas of the northern part of the Sahara where it seems to find its optimum development. The objective of the study is the floristic and ecological characterisation of the steppe vegetation groups of H. scoparia after 4 years of enclosure grazing (Eg). For the past three decades, steppe of H. scoparia were completely overwhelmed, both in their structure and their operation by increasing the herd and the continued use of natural pastures using animal load significantly higher than the production potential of course, which is reflected by the reduction of their capacity for natural regeneration. Intervention measures that address this alarming situation are to foster the inverse process of degradation reconstruction and rehabilitation of degraded steppe rangelands by the technique of the Eg. The methodology involves a device that is composed of a series of transects that constitute a grid and allow to scan the whole website for Eg and part of the neighbouring paths. The results emphasise the interest and constructive impact of the Eg on plant diversity and the fight against the factors of degradation and desertification. This review highlights the importance of the technique of Eg for the rehabilitation and restoration of steppe rangelands in arid bioclimate.

Late Holocene Sea Temperatures along the Central California Coast

1999 ◽  
Vol 51 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Terry L. Jones ◽  
Douglas J. Kennett
Keyword(s):  
Late Holocene ◽  
Fish Bone ◽  
Archaeological Sites ◽  
Central California ◽  
The Past ◽  
Past 2000 Years ◽  
Terrestrial Productivity ◽  
Continued Use ◽  
Mussel Shells ◽  
Marine Productivity

AbstractMussel shells from central California coastal archaeological sites record changes in sea surface temperatures in the past 2000 years. Water temperatures, inferred from oxygen isotopes in the shells, were about 1°C cooler than present and stable between 2000 and 700 yr ago. Between about 700 and 500 yr ago, seasonal variation was greater than present, with extremes above and below historic levels. Water temperatures were 2–3°C cooler than today 500–300 yr ago. The interval of variable sea temperatures 700–500 yr ago partially coincided with an interval of drought throughout central California. A coincident disruption in human settlement along the coast suggests movements of people related to declining water sources. Quantities of fish bone in central coast middens dating to this same period are high relative to other periods, and the remains of northern anchovies, a species sensitive to changing oceanographic conditions, are also abundant. The continued use of local fisheries suggests that changes in settlement and diet were influenced more by drought than by a decrease in marine productivity, as fish provided a staple during an interval of low terrestrial productivity.

Airborne Laser Scanning in Poland - Between Science and Practice

2019 ◽  
Vol 31 (1) ◽  
pp. 105-133
Author(s):  
Zdzisław Kurczyński
Keyword(s):  
Remote Sensing ◽  
Retrospective Analysis ◽  
Laser Scanning ◽  
Airborne Laser Scanning ◽  
Production Potential ◽  
Development Trends ◽  
The Past ◽  
Airborne Laser ◽  
National Production ◽  
Research Centres

Abstract The article is a retrospective analysis of the development of airborne laser scanning technology in the country in the past twenty years, i.e. from the beginnings of this technique use in Poland to the present day. The emphasis in the text is placed on development trends and scientific and application problems in the field of technology undertaken by national research centres. The review is based on numerous publications in this field, which have been released over two decades mainly in the “Archive of Photogrammetry, Cartography and Remote Sensing”. Therefore, the article is a presentation of the progress in the area of airborne laser scanning through an attempt to systematize and review national publications in this scope. It also presents the development of the national production potential and the level of the country’s coverage with data and products derived from airborne laser scanning.

scholarly journals PASTURE REGENERATION: WITHER HILLS

1949 ◽  
pp. 72-80
Author(s):  
D.R. Wilkie
Keyword(s):  
Natural Regeneration ◽  
The Past

The process of natural regeneration of pastures is one on which during the past 20 years there has been a deal of discussion and experimentation, but on which there has, in this country, been little enough action on a practical scale.

scholarly journals Response of pollen diversity to the climate-driven altitudinal shift of vegetation in the Colombian Andes

2006 ◽  
Vol 362 (1478) ◽  
pp. 253-262 ◽  
Author(s):  
Chengyu Weng ◽  
Henry Hooghiemstra ◽  
Joost F Duivenvoorden
Keyword(s):  
Plant Diversity ◽  
Climatic Conditions ◽  
Fossil Pollen ◽  
Tropical Andes ◽  
Lower Altitude ◽  
The Past ◽  
Colombian Andes ◽  
Altitudinal Shift ◽  
Study Sites ◽  
The Relationship

Change in diversity of fossil pollen through time is used as a surrogate for biodiversity history. However, there have been few studies to explore the sensitivity of the measured pollen diversity to vegetation changes and the relationship between pollen diversity and plant diversity. This paper presents results of a study to assess the relationship between pollen diversity and relative abundance of pollen from different altitudinal vegetation belts (subandean forest, Andean forest, subparamo and grassparamo) in three records from the tropical Andes in Colombia. The results indicated that plant diversity in the vegetation declined with altitude and pollen diversity is positively correlated to the abundance of pollen from lower altitude vegetation belts and negatively correlated to that from the grassparamo. These results, therefore, suggest that pollen diversity coarsely reflects the diversity of the surrounding vegetation. Using this interpretation, we were able to predict changes in plant diversity over the past 430 000 years in the Colombian Andes. Results indicated that under warmer climatic conditions, more species-diverse vegetation of low elevation moved upslope to contribute more pollen diversity to the study sites, and under colder conditions, species-poor grassparamo moved downslope and observed pollen diversity was lower. This study concludes that fossil pollen diversity may provide an important proxy to reconstruct the temporal changes in plant diversity.

scholarly journals Plants Used as Fence and Fuelwood in Manang District, Central Nepal

1970 ◽  
Vol 5 (5) ◽  
pp. 107-111 ◽  
Author(s):  
S Bhattarai ◽  
RP Chaudhary ◽  
RSL Taylor
Keyword(s):  
Local People ◽  
Wild Plants ◽  
Community Forest ◽  
The Past ◽  
Central Nepal ◽  
The People ◽  
Scientific World ◽  
Crop Field ◽  
Continued Use ◽  
Forest Use

The remoteness of Manang District, Central Nepal has resulted in continued use of wild plants to meet daily needs. Local people were interviewed during 2002-2006 regarding the uses of plants as sources of fence and fuelwood. The People of Manang have been using 16 plant species (eight trees and eight shrubs) which belong to nine families and 10 genera for fence and fuelwood. The highest number of species belonged to Berberidaceae (4 species), followed by Cupressaceae (3 species), Rosaceae and Pinaceae (2 species each). Taxaceae, Elaeagnaceae, Betulaceae, Salicaceae and Juglandaceae were represented by one species each. Among 16 species recorded, eleven species including Berberis lycium, Hippophae salicifolia, Juniperus indica, Rosa macrophylla, etc., were used as fence and 11 species including Betula utilis, Juniperus indica, Pinus wallichiana, etc., were used as a source of fuelwood. Some plants are used as both fence and fuelwood. Fence plants protect crop field from damage by livestock and wild animals and prevented soil erosion by wind. The local people of TankiManang, Manang, Braka, Munji do not collect fuelwood, and furniture wood from their nearby forest these days as they did in the past and now collect from the next village (Hongde and Pisang forest). This a good example of awareness towards conservation and forest management. The forests near their villages are now named as ‘community forest'. There is a continued need for awareness among the people about forest use and its role in the environment. Key words: Awareness; Community forest; Livestock; Manang; Wild plants. DOI: 10.3126/sw.v5i5.2666 Scientific World, Vol. 5, No. 5, July 2007 107-111

scholarly journals Development and dynamics of mountain spruce (Picea abies [L.] Karsten) stand regeneration

2014 ◽  
Vol 60 (No. 2) ◽  
pp. 61-69 ◽  
Author(s):  
K. Malík ◽  
J. Remeš ◽  
S. Vacek ◽  
V. Štícha
Keyword(s):  
Picea Abies ◽  
Bark Beetle ◽  
Natural Regeneration ◽  
National Park ◽  
Height Growth ◽  
Seedling Height ◽  
Artificial Regeneration ◽  
Class Differences ◽  
The Past ◽  
Tree Layer

We summarized development and dynamics of natural regeneration in mountain spruce forests in areas affected by bark beetle gradation in the Šumava National Park. Detailed measurements of the regeneration were carried out using Field-Map technology (www.fieldmap.com) on ten permanent research plots. Research plots included the forests with decaying tree layer, stands in partial decline and stands with a generally healthy, or only partially damaged tree layer. Differences in rates of regeneration are very significant between the particular types of plots, especially in the youngest age class. Differences are also evident in the seedling height under varying treatments. The highest numbers of recruits (9,880 per ha) were found under intact overstorey canopies, while the fastest height growth occurred on clearcuts. This study also investigated and evaluated artificial regeneration done in the past.  

Estimating the Quotient in Division: A Critical Analysis of Research

1957 ◽  
Vol 4 (3) ◽  
pp. 100-111
Author(s):  
Maurice L. Hartung
Keyword(s):  
Present Article ◽  
Critical Analysis ◽  
The Other ◽  
Direct Process ◽  
Inverse Process ◽  
The Past ◽  
Considerable Research

There are several reasons why the process of division in arithmetic is more difficult to learn than the other processes. One of these reasons stems from the fact that division is not a direct process. It is an inverse process in which it is frequently necessary to estimate in finding the quotient. In the past, two methods of estimating the quotient have been in common use. One of these is generally called the “apparent quotient” method and the other is called the “increase-byone” method. There has been considerable research directed toward determining whieh of these methods is to be preferred for instructional purposes. The present article is not only a summary and critique of this research but also includes numerous comments upon aspects of the issue which have hitherto been largely neglected.

scholarly journals An annotated checklist of vascular plants of Cherangani hills, Western Kenya

PhytoKeys ◽  
2019 ◽  
Vol 120 ◽  
pp. 1-90 ◽  
Author(s):  
Yuvenalis Morara Mbuni ◽  
Yadong Zhou ◽  
Shengwei Wang ◽  
Veronicah Mutele Ngumbau ◽  
Paul Mutuku Musili ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Endemic Species ◽  
Vascular Plants ◽  
Herbarium Specimens ◽  
Western Kenya ◽  
The Past ◽  
Field Investigations ◽  
Voucher Specimens ◽  
Diversity Studies ◽  
Annotated Checklist

Cherangani hills, located in Western Kenya, comprises of 12 forest blocks, maintaining great plant diversity. However, little attention to plant diversity studies has been paid to it in the past years. Here, we present a checklist of the vascular plants of this region obtained through intensive field investigations and matching of herbarium specimens. In total, 1296 species, including 17 endemic species are documented, belonging to 130 families and 608 genera. This flora represents 18.50%, 43.83% and 54.17% of the Kenyan species, genera and families, respectively. The habit, habitat and voucher specimens, as well as brief notes on the distribution of each taxon recorded are presented in this checklist. It is the first exhaustive inventory of the terrestrial vascular plants in Cherangani hills which is a significant regional centre for plant diversity.

REHABILITATION OF AN ICONIC SKYSCRAPER POISED TO SPUR REVITALIZATION OF A DOWNTOWN NEIGHBORHOOD

2016 ◽  
Vol 11 (3) ◽  
pp. 35-54
Author(s):  
Robert C. Burns ◽  
Patrick Thompson
Keyword(s):  
Art Deco ◽  
The Past ◽  
The Great Depression ◽  
Contemporary Life ◽  
History Of ◽  
National Bank ◽  
Lofty Goal ◽  
Continued Use ◽  
The City ◽  
Fringe Area

INTRODUCTION The revitalization of downtown Richmond, Virginia, in the 21st century has been a slow process, beginning in the financial center near the State Capitol Building and migrating slowly westward along Broad Street, the traditional retail avenue of the City. One by one over the course of the past several years, large, iconic buildings have been rehabilitated for new and exciting uses. These buildings have long been associated with the history of the City itself: the Miller & Rhoads Department Store, the John Marshall Hotel, the First National Bank Building, and the Hotel Richmond among others. The Central National Bank (CNB) Building was built at the dawn of the Great Depression and eventually became one of the last Art Deco style skyscrapers remaining in downtown Richmond. Its location in the neglected western fringe area of Broad Street made it the next logical target for rehabilitation. When Douglas Development purchased the vacant building in 2005, they were buying the crowning piece of architecture that they hoped would become the linchpin project to spur the revitalization of the surrounding neighborhood. That lofty goal was not without challenges, of course, and it took 8 years to put the project together and start the building's renovation. The complications inherent in the rehabilitation of any iconic 75-year old building listed on the National Register of Historic Places to suit continued use for contemporary life also clearly came into play.

Tree Improvement Research and Development in Canada

1990 ◽  
Vol 66 (2) ◽  
pp. 97-102 ◽  
Author(s):  
D. P. Fowler ◽  
E. K. Morgenstern
Keyword(s):  
Research And Development ◽  
Forest Fires ◽  
Natural Regeneration ◽  
Large Scale ◽  
Tree Improvement ◽  
Artificial Regeneration ◽  
The Past ◽  
Forest Industries ◽  
Improvement Programs ◽  
Reforestation Program

As a result of increased utilization of the forest resources in Canada and large losses to forest fires, insects and diseases natural regeneration has been found to be inadequate and artificial regeneration by seeding and planting has been developed on a large scale during the past 30 years. This expansion of the reforestation program has provided the stimulus for the development of tree improvement programs in all 10 provinces. The role and cooperation of federal and provincial organizations, forest industries and universities in research and development is described.

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