scholarly journals Analysis of Herbaceous Plant Succession and Dispersal Mechanisms in Deglaciated Terrain on Mt. Yulong, China

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Li Chang ◽  
Yuanqing He ◽  
Taibao Yang ◽  
Jiankuo Du ◽  
Hewen Niu ◽  
...  
Keyword(s):  
Ecological Succession ◽  
Plant Succession ◽  
Herbaceous Plant ◽  
Sparse Vegetation ◽  
Dominant Plant Species ◽  
Bare Land ◽  
Community Types ◽  
Last Stage ◽  
Succession Process ◽  
Succession Stage

Ecological succession itself could be a theoretical reference for ecosystem restoration and reconstruction. Glacier forelands are ideal places for investigating plant succession because there are representative ecological succession records at long temporal scales. Based on field observations and experimental data on the foreland of Baishui number 1 Glacier on Mt. Yulong, the succession and dispersal mechanisms of dominant plant species were examined by using numerical classification and ordination methods. Fifty samples were first classified into nine community types and then into three succession stages. The three succession stages occurred about 9–13, 13–102, and 110–400 years ago, respectively. The earliest succession stage contained the association ofArenaria delavayi +Meconopsis horridula. The middle stage contained the associations ofArenaria delavayi + Kobresia fragilis,Carex capilliformis +Polygonum macrophyllum,Carex kansuensis, and alsoPedicularis rupicola. The last stage included the associations ofKobresia fragilis + Carex capilliformis,Kobresia fragilis,Kobresia fragilis+Ligusticum rechingerana, andKobresia fragilis + Ligusticum sikiangense. The tendency of the succession was from bare land to sparse vegetation and then to alpine meadow. In addition, three modes of dispersal were observed, namely, anemochory, mammalichory, and myrmecochory. The dispersal modes of dominant species in plant succession process were evolved from anemochory to zoochory.

Herbaceous Plant Succession at Sand Prairie-scrub Oak Nature Preserve, Mason County, Illinois

Rhodora ◽  
2008 ◽  
Vol 110 (942) ◽  
pp. 171-177
Author(s):  
William E. McClain ◽  
John E. Ebinger
Keyword(s):  
Plant Succession ◽  
Herbaceous Plant ◽  
Scrub Oak ◽  
Nature Preserve ◽  
Mason County

scholarly journals Plant succession in a forest on the Lower Northeast Slope of Serra Geral, Rio Grande do Sul, and Holocene palaeoenvironments, Southern Brazil

2007 ◽  
Vol 21 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Márcia Grala Leal ◽  
Maria Luisa Lorscheitter
Keyword(s):  
Water Reservoir ◽  
Rio Grande ◽  
Plant Succession ◽  
Tropical Species ◽  
Herbaceous Plant ◽  
Rio Grande Do Sul ◽  
Swamp Forest ◽  
Local Water ◽  
In The Beginning ◽  
Glycerol Jelly

The study of plant succession provides information on vegetation dynamics of a region and, therefore, improves our understanding of the natural trends of present ecosystems. With this objective, plant succession based on palynology of a sediment profile in a swamp forest was studied on the Lower Northeast Slope of Serra Geral, Rio Grande do Sul. Samples were treated with HCl, HF, KOH and acetolysis; slides were mounted in glycerol-jelly. For each sample a minimum of 500 grains of pollen + pteridophyte and bryophyte spores was counted and other palynomorphs were counted in parallel. Tilia and Tilia Graph software were used to construct percentage and concentration diagrams, with three 14C datings. The results show a local water reservoir in the beginning of the Holocene (± 9800 yrs. BP), creating a herbaceous plant marsh by hydrosere. The initial colonization of the marsh by trees occurred about 8800 yrs. BP, with tropical species from the Coastal Plain migrating in an east-west direction. Afterwards, there was a dry phase between 7000-5000 yrs. BP. The second appearance of regional tree species began at about 5000 yrs. BP, resulting in the present forest and in the west-east migration of tropical species from interior lowlands, like this one, to re-colonize the coast after the last marine regression.

scholarly journals Bryophyte communities across the ecological succession process in the Caxiuanã National Forest, Pará, Brazil

2020 ◽  
Vol 92 (1) ◽  
Author(s):  
TÁSSIA T.G. TAKASHIMA-OLIVEIRA ◽  
PRISCILA S. DE MEDEIROS ◽  
ANA CLÁUDIA C. TAVARES-MARTINS
Keyword(s):  
Ecological Succession ◽  
National Forest ◽  
Succession Process

scholarly journals Comparing LiDAR and SfM digital surface models for three land cover types

2021 ◽  
Vol 13 (1) ◽  
pp. 497-504
Author(s):  
Jianghua Liao ◽  
Jinxing Zhou ◽  
Wentao Yang
Keyword(s):  
Land Cover ◽  
Airborne Lidar ◽  
Light Detection And Ranging ◽  
Land Cover Types ◽  
Sparse Vegetation ◽  
Surface Models ◽  
Vehicle Structure ◽  
Bare Land ◽  
Different Types ◽  
Aerial Vehicle

Abstract Airborne light detection and ranging (LiDAR) and unmanned aerial vehicle structure from motion (UAV-SfM) are two major methods used to produce digital surface models (DSMs) for geomorphological studies. Previous studies have used both types of DSM datasets interchangeably and ignored their differences, whereas others have attempted to locally compare these differences. However, few studies have quantified these differences for different land cover types. Therefore, we simultaneously compared the two DSMs using airborne LiDAR and UAV-SfM for three land cover types (i.e. forest, wasteland, and bare land) in northeast China. Our results showed that the differences between the DSMs were the greatest for forest areas. Further, the average elevation of the UAV-SfM DSM was 0.4 m lower than that of the LiDAR DSM, with a 95th percentile difference of 3.62 m for the forest areas. Additionally, the average elevations of the SfM DSM for wasteland and bare land were 0.16 and 0.43 m lower, respectively, than those of the airborne LiDAR DSM; the 95th percentile differences were 0.67 and 0.64 m, respectively. The differences between the two DSMs were generally minor over areas with sparse vegetation and more significant for areas covered by tall dense trees. The findings of this research can guide the joint use of different types of DSMs in certain applications, such as land management and soil erosion studies. A comparison of the DSM types in complex terrains should be explored in the future.

Diversité floristique d’un lac du bas-sahara algérien. Flora diversity of a lake at algerian low-sahara

2012 ◽  
Vol 37 ◽  
pp. 33-44 ◽  
Author(s):  
Haroun Chenchouni
Keyword(s):  
Life Forms ◽  
Systematic Sampling ◽  
Phragmites Communis ◽  
Sparse Vegetation ◽  
Plant Life Forms ◽  
Plant Life ◽  
Dominant Plant Species ◽  
Juncus Maritimus ◽  
Adverse Environmental Conditions ◽  
Flora Diversity

Français.  Nous avons examiné la composition et la dynamique de la végétation vasculaire spontanée dans le Lac Ayata (Vallée d’Oued Righ, Bas-Sahara algérien). Le site se situe entre 33°29’17’’N à 33°29’48’’N et 05°59’10’’E à 05°59’37’’E. L’échantillonnage systématique de la flore a révélé l’existence de 13 espèces appartenant à 8 familles et 13 genres. Le plan d’eau est dépourvu de plantes submergées. Les types biologiques, la structure et la physionomie de la végétation sont été déterminés. L’occupation du sol par la végétation est cartographiée afin d’illustrer les répartitions saisonnières des espèces végétales dominantes. Des géostatistiques sur les surfaces occupées par la végétation ainsi que sur sa dynamique saisonnière sont ensuite obtenues puis discutées. Les types biologiques les plus fréquents sont les chamaephytes (53,8%) et les thérophytes (23,1%), qui caractérisent la végétation désertique ayant un recouvrement faible et une hauteur basse. Par ailleurs, la cartographie de la végétation a révélé l’existence de 3 types de formations végétales: (i) une végétation halophytique représentée par des espèces Chénopodiacées qui sont réparties tout autour des abords du plan d’eau; (ii) une végétation hydrophytique représentée par Phragmites communis et Juncus maritimus ; et (iii) une végétation éparse représentée par Limoniastrum guyonianum et Triganum nudatum. Le lac Ayata abrite une flore peu diversifiée mais bien adaptée aux conditions écologiques défavorables qui règnent sur le sol (salinité) et le climat (sécheresse).English. We examined the composition and dynamics of spontaneous vascular vegetation in Lake Ayata (Valley of Oued Righ Algerian, Low-Sahara). The site is located between 33°29’17’’N to 33°29’48’’N and 05°59’10’’E to 05°59’37’’E. A systematic sampling of the flora has revealed 13 species belonging to 8 families and 13 genera. The waterbody is free of submerged plants. The plant life forms, structure and physiognomy of vegetation were determined. In addition, vegetation-land-cover was mapped to illustrate seasonal distribution of dominant plant species. Geostatistics on areas covered by vegetation and its seasonal dynamics were obtained and then discussed. The most common plant life forms were chamaephytes (53.8%) and therophytes (23.1%), which characterize desert vegetation that has low recovery and low height. Furthermore, vegetation mapping revealed the existence of 3 types of vegetation: (i) halophytic vegetation represented mainly by Chenopodiaceae species, which were extended all around the edges of the waterbody; (ii) hydrophytic vegetation represented mainly by Phragmites communis and Juncus maritimus, and (iii) sparse vegetation represented by Limoniastrum guyonianum and Triganum nudatum. Lake Ayata’s flora is poorly diversified but well adapted to adverse environmental conditions prevailing on the ground (salinity) and climate (drought). 

scholarly journals Development of Neural Network Based Adaptive Change Detection Technique for Land Terrain Monitoring with Satellite and Drone Images

2019 ◽  
Vol 69 (5) ◽  
pp. 474-480
Author(s):  
Ankush Agarwal ◽  
Sandeep Kumar ◽  
Dharmendra Singh
Keyword(s):  
Neural Network ◽  
Change Detection ◽  
Satellite Images ◽  
Satellite Image ◽  
Sparse Vegetation ◽  
Dense Vegetation ◽  
Bare Land ◽  
Good Potential ◽  
Sentinel 2

Role of satellite images is increasing in day-to-day life for both civil as well as defence applications. One of the major defence application while troop’s movement is to know about the behaviour of the terrain in advance by which smooth transportation of the troops can be made possible. Therefore, it is important to identify the terrain in advance which is quite possible with the use of satellite images. However, to achieve accurate results, it is essential that the data used should be precise and quite reliable. To achieve this with a satellite image alone is a challenging task. Therefore, in this paper an attempt has been made to fuse the images obtained from drone and satellite, to achieve precise terrain information like bare land, dense vegetation and sparse vegetation. For this purpose, a test area nearby Roorkee, Uttarakhand, India has been selected, and drone and Sentinel-2 data have been taken for the same dates. A neural network based technique has been proposed to obtain precise terrain information from the Sentinel-2 image. A quantitative analysis was carried out to know the terrain information by using change detection. It is observed that the proposed technique has a good potential to identify precisely bare land, dense vegetation, and sparse vegetation which may be quite useful for defence as well as civilian application.

scholarly journals Digital Examination of Vegetation Changes in River Floodplain Wetlands Based on Remote Sensing Images: A Case Study Based on the Downstream Section of Hailar River

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1206
Author(s):  
Xi Dong ◽  
Zhibo Chen
Keyword(s):  
Remote Sensing ◽  
Water Supply ◽  
Plant Community ◽  
Vegetation Change ◽  
Vegetation Index ◽  
Forest Vegetation ◽  
High Rate ◽  
Vegetation Changes ◽  
Herbaceous Plant ◽  
Sparse Vegetation

The Hailar River is an important river in the Inner Mongolia Autonomous Region, China. It plays an extremely important role in maintaining the ecological balance of the region. However, in recent decades, the Hailar River and its surrounding areas have been developed at a high rate and its wetland resources have faced various threats. In this study, vegetation changes in the Hailar River wetlands were analyzed using remote sensing data from the Landsat TM (1987, 2001, and 2010) and Landsat OLI-TIRS (2019) satellites. A vegetation change model was developed using Matlab software to assess vegetation changes in the area. There were significant changes in the wetland vegetation of the lower Hailar River study site between 1987 and 2019. There was an increase in open sand habitat with a sparse vegetation area of 1.08 km2, a decrease in grassland area of 13.17 km2, and an increase in the forest area of 15.91 km2. The spatial distribution of the normalized difference vegetation index (NDVI) varied across the study site and was high overall. The vegetation types varied with distance from the river. There are two possible explanations for positive and negative vegetation change trends. In areas where the water supply is sufficient and relatively stable, the cover of forest vegetation was gradually increasing and the herbaceous plant community is gradually evolving into a scrub woodland plant community. In areas where the water supply is lacking, there are changes in the sense of a decrease of forest vegetation and an increase of open sand habitat with sparse vegetation. Therefore, this study suggests that the existing wetlands should be protected, used wisely, and developed rationally to provide sustainable resources for the next generation.

Landscape Change in the Steppe of Algeria South-West Using Remote Sensing

2018 ◽  
Vol 18 (1) ◽  
pp. 41-52
Author(s):  
Tayeb Sitayeb ◽  
Ishak Belabbes
Keyword(s):  
Remote Sensing ◽  
Social Systems ◽  
Bare Soil ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Landsat 8 ◽  
Natural Ecosystems ◽  
Stipa Tenacissima ◽  
Steppe Species ◽  
Sparse Vegetation

Abstract Landscape dynamics is the result of interactions between social systems and the environment, these systems evolving significantly over time. climatic conditions and biophysical phenomena are the main factors of landscape dynamics. Also, currently man is responsible for most changes affecting natural ecosystems. The objective of this work is to study the dynamics of a typical landscape of western Algeria in time and space, and to map the distribution of vegetation groups constitute the vegetation cover of this ecosystem. as well as using a method of monitoring the state of a fragile ecosystem by remote sensing to understand the processes of changes in this area. The steppe constitutes a large arid area, with little relief, covered with low and sparse vegetation. it lies between the annual isohyets of 100 to 400 mm, subjected to a very old human exploitation with an activity of extensive breeding of sheep, goats, and camels. Landsat satellite data were used to mapping vegetation groups in the Mecheria Steppe at a scale of 1: 300,000. Then, a comparison was made between the two maps obtained by a classification of Landsat-8 sensor Operational Land Imager (OLI) acquired on March 18, 2014, and Landsat-5 sensor Thematic Mapper (TM) acquired on April 25, 1987. The results obtained show the main changes affecting the natural distribution of steppe species, a strong change in land occupied by the Stipa tenacissima steppe with 65% of change, this steppe is replaced by Thymelaea microphylla, Salsola vermiculata, lygeum spartum and Peganum harmala steppe. an absence from the steppe Artemisia herba-alba that has also been replaced by the same previous steppes species. The groups with Quercus ilex and Juniperus phoenicea are characterized by a strong regression that was lost 60% of its global surface and transformed by steppe to stipa tenacissima and bare soil.

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