scholarly journals A millennium of increasing ecosystem diversity until the mid-20th century

2021 ◽  
Author(s):  
Inês S. Martins ◽  
Maria Dornelas ◽  
Mark Vellend ◽  
Chris D. Thomas
Keyword(s):  
Land Use ◽  
20Th Century ◽  
Human Impacts ◽  
Land Use Changes ◽  
Global Scale ◽  
Last Millennium ◽  
Human Land Use ◽  
Land Use Types ◽  
Global Land ◽  
Ecosystem Diversity

AbstractLand-use change is widely regarded as a simplifying and homogenising force in nature. In contrast, analysing global land-use reconstructions from the 10th to 20th centuries, we found progressive increases in the number, evenness, and diversity of ecosystems (including human-modified land-use types) across the globe. Ecosystem diversity increased more rapidly after ∼1700CE, then slowed or partially reversed (depending on the metric) following the mid-20th century acceleration of human impacts. Differentiation also generally increased across space, with homogenization only evident in the presence-absence analysis of ecosystem types at the global scale. Our results suggest that human land-use changes have primarily driven increases in ecosystem diversity over the last millennium.

Impact of agrarian practices and some pastoral uses on vegetation in Algerian steppe rangelands

2019 ◽  
Vol 41 (2) ◽  
pp. 97
Author(s):  
R. F. Hammouda ◽  
J. Huguenin ◽  
L. Julien ◽  
D. Nedjraoui
Keyword(s):  
Land Use ◽  
20Th Century ◽  
Plant Communities ◽  
General Trend ◽  
Human Impacts ◽  
Land Use Changes ◽  
Herd Size ◽  
Study Zone ◽  
Considerable Impact ◽  
Biophysical Environment

The decline in steppe vegetation in Algeria was first reported in the mid-20th century, and for many years was attributed to recurrent droughts. Hypotheses suggesting that this decline was a consequence of human activities emerged in the 1970s – a time of major socioeconomic trends in the region. Changes such as strong population growth, sedentarisation, herd size increases and use of pasture land for crops, all had considerable impact on rangeland vegetation. The aim of the present work was to identify heterogeneity in the pasture vegetation of a given ‘territory’ (in the sense of a ‘terroir’), or biophysical environment (including meteorological), taking into account rangeland distribution, land use changes and herd management in the Aflou region of Algeria. Characterisation and mapping of the vegetation and its environment in the study area led to the hypothesis that, apart from some very slight soil differences, heterogeneity in rangeland vegetation appeared mainly related to human impacts. Bertin’s Semiology of Graphics was used to analyse the results, and indicated a major decline in vegetation productivity and biodiversity in the steppe rangelands of the study zone. Beyond this general trend in the municipal territory studied, areas were found with contrasting flora communities, with some showing relatively stable plant communities, while other areas had some plant communities that had undergone regressive succession. Grazing conditions and the proximity of ploughed land were responsible for these different vegetation situations.

Mistletoes in a changing world: a premonition of a non-analog future?

Botany ◽  
2020 ◽  
Vol 98 (9) ◽  
pp. 479-488
Author(s):  
Francisco E. Fontúrbel
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Biodiversity Loss ◽  
Global Scale ◽  
Ecological Interactions ◽  
Human Disturbances ◽  
Climate Change Effects ◽  
Long Run ◽  
Plant Animal Interactions ◽  
Changing World

Mistletoes are a group of flowering plants that have developed a parasitic lifeform through complex eco-evolutionary processes. Despite being considered a pest, mistletoes represent a keystone forest resource and are involved in complex plant–plant and plant–animal interactions. Their parasitic lifeform and specialized ecological interactions make mistletoes an ideal model with which to understand the effects of anthropogenic disturbances in a changing world. The accelerated growth of the human population has altered all ecosystems on Earth, leading to biodiversity loss. Land-use changes (involving habitat loss, fragmentation, degradation, and transformation processes) can alter the ecological scenario for mistletoe by altering hosts, mutualists, and nutrient cycling. Those changes may have large consequences at the community level, changing the spatial structure of mistletoes, as well as interaction effectiveness, facilitation process, interaction disruption, and novel interactions with invasive species, leading to non-analog communities in the long run. Furthermore, climate change effects operate on a global scale, enhancing the effects of land-use changes. As temperatures increase, many species would alter their distribution and phenology, potentially causing spatial and temporal mismatches. But more critical is the fact that water stress is likely to disrupt key ecological interactions. Thus, mistletoes can provide valuable insights for what we can expect in the future, as a result of human disturbances.

scholarly journals Landscape typology in Czechia and abroad: State of the art, methods and theoretical basis

Geografie ◽  
2007 ◽  
Vol 112 (1) ◽  
pp. 61-83
Author(s):  
Zdeněk Lipský ◽  
Dušan Romportl
Keyword(s):  
Land Use ◽  
Theoretical Basis ◽  
State Of The Art ◽  
Human Impacts ◽  
Land Use Changes ◽  
European Countries ◽  
Intensive Agriculture ◽  
European Landscape Convention ◽  
Character Assessment ◽  
Landscape Character

The main goal of this paper is to introduce the importance of landscape typology in present times when many landscapes are exposed to dynamic human impacts such as land use changes, urbanization, intensive agriculture, forestry or industrialization. Different approaches to landscape typology in Czechia and other European countries as well as relations of landscape typology to landscape character assessment and the European Landscape Convention are discussed. A requirement of a new exact and applicable landscape typology is a great challenge for Czech geographers.

scholarly journals Effects of Climate and Land Use changes on Vegetation Dynamics in the Yangtze River Delta, China Based on Abrupt Change Analysis

2020 ◽  
Vol 12 (5) ◽  
pp. 1955
Author(s):  
Lei Wan ◽  
Huiyu Liu ◽  
Haibo Gong ◽  
Yujia Ren
Keyword(s):  
Land Use ◽  
Vegetation Dynamics ◽  
Abrupt Change ◽  
Land Use Changes ◽  
Yangtze River Delta ◽  
Change Analysis ◽  
Land Use Types ◽  
Natural Land ◽  
Abrupt Change Analysis ◽  
Relationship Of

Vegetation dynamics is thought to be affected by climate and land use changes. However, how the effects vary after abrupt vegetation changes remains unclear. Based on the Mann-Kendall trend and abrupt change analysis, we monitored vegetation dynamics and its abrupt change in the Yangtze River delta during 1982–2016. With the correlation analysis, we revealed the relationship of vegetation dynamics with climate changes (temperature and precipitation) pixel-by-pixel and then with land use changes analysis we studied the effects of land use changes (unchanged or changed land use) on their relationship. Results showed that: (1) the Normalized Vegetation Index (NDVI) during growing season that is represented as GSN (growing season NDVI) showed an overall increasing trend and had an abrupt change in 2000. After then, the area percentages with decreasing GSN trend increased in cropland and built-up land, mainly located in the eastern, while those with increasing GSN trend increased in woodland and grassland, mainly located in the southern. Changed land use, except the land conversions from/to built-up land, is more favor for vegetation greening than unchanged land use (2) after abrupt change, the significant positive correlation between precipitation and GSN increased in all unchanged land use types, especially for woodland and grassland (natural land use) and changed land use except built-up land conversion. Meanwhile, the insignificant positive correlation between temperature and GSN increased in woodland, while decreased in the cropland and built-up land in the northwest (3) after abrupt change, precipitation became more important and favor, especially for natural land use. However, temperature became less important and favor for all land use types, especially for built-up land. This research indicates that abrupt change analysis will help to effectively monitor vegetation trend and to accurately assess the relationship of vegetation dynamics with climate and land use changes.

scholarly journals Using Landsat Thematic Mapper (TM) sensor to detect change in land surface temperature in relation to land use change in Yazd, Iran

Solid Earth ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 1551-1564 ◽  
Author(s):  
Sajad Zareie ◽  
Hassan Khosravi ◽  
Abouzar Nasiri ◽  
Mostafa Dastorani
Keyword(s):  
Land Use ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Land Use Changes ◽  
Thermal Conditions ◽  
Kappa Coefficient ◽  
Thematic Mapper ◽  
Landsat Thematic Mapper ◽  
Land Use Types

Abstract. Land surface temperature (LST) is one of the key parameters in the physics of land surface processes from local to global scales, and it is one of the indicators of environmental quality. Evaluation of the surface temperature distribution and its relation to existing land use types are very important to the investigation of the urban microclimate. In arid and semi-arid regions, understanding the role of land use changes in the formation of urban heat islands is necessary for urban planning to control or reduce surface temperature. The internal factors and environmental conditions of Yazd city have important roles in the formation of special thermal conditions in Iran. In this paper, we used the temperature–emissivity separation (TES) algorithm for LST retrieving from the TIRS (Thermal Infrared Sensor) data of the Landsat Thematic Mapper (TM). The root mean square error (RMSE) and coefficient of determination (R2) were used for validation of retrieved LST values. The RMSE of 0.9 and 0.87 °C and R2 of 0.98 and 0.99 were obtained for the 1998 and 2009 images, respectively. Land use types for the city of Yazd were identified and relationships between land use types, land surface temperature and normalized difference vegetation index (NDVI) were analyzed. The Kappa coefficient and overall accuracy were calculated for accuracy assessment of land use classification. The Kappa coefficient values are 0.96 and 0.95 and the overall accuracy values are 0.97 and 0.95 for the 1998 and 2009 classified images, respectively. The results showed an increase of 1.45 °C in the average surface temperature. The results of this study showed that optical and thermal remote sensing methodologies can be used to research urban environmental parameters. Finally, it was found that special thermal conditions in Yazd were formed by land use changes. Increasing the area of asphalt roads, residential, commercial and industrial land use types and decreasing the area of the parks, green spaces and fallow lands in Yazd caused a rise in surface temperature during the 11-year period.

scholarly journals Larval Ecology of Anopheles Mosquitoes in Kudat, Sabah

2021 ◽  
Author(s):  
Wilfredo Escalante Aure ◽  
Nelia Palaria Salazar ◽  
Tock Hing Chua
Keyword(s):  
Land Use ◽  
Plasmodium Knowlesi ◽  
Land Use Changes ◽  
Rubber Tree ◽  
Tree Plantation ◽  
Breeding Sites ◽  
Larval Habitats ◽  
Anopheles Mosquitoes ◽  
Land Use Types ◽  
Average Maximum

The emergence of human Plasmodium knowlesi malaria appeared to have been precipitated by the displacement of the natural environment of macaques and Anopheles mosquitoes resulting from deforestation and land-use changes in Malaysia. A longitudinal survey of larval habitats was conducted from May 2015 to April 2016 in the District of Kudat, Sabah to better understand how these changes have affected mosquitoes across six land use categories. Larvae were collected by dipping and reared in the laboratory for the identification of adults. Five anopheline and three culicine species were present: Anopheles balabacensis, An. barbirostris, An. lesteri, An. borneensis, An. umbrosus, Aedes albopictus, Culex gelidus, and Toxorhynchites sp. An. balabacensis was found in all six land-use types. Biodiversity by genera was high in all land-use types. The relative importance of land use types and larval habitats as sources of potential vectors was analyzed by the Kruskal-Wallis H test by ranks. In decreasing order Anopheles larvae were found in rubber tree plantation > coconut plantation > clearing site > palm oil plantation > forest > settlement area. Important larval habitats were intermittent stream > ditch > pond > artificial container > puddle > river > slow-flowing stream. Eighteen breeding sites of An. balabacensis were within (500 m) the average maximum flight range of the species and houses at risk for malaria. Knowledge gained from the study can be used to assess the need for vector control in preventing the spread of P. knowlesi in vulnerable areas.  

scholarly journals Global Transition Rules for Translating Land-use Change (LUH2) To Land-cover Change for CMIP6 using GLM2

2019 ◽  
Author(s):  
Lei Ma ◽  
George C. Hurtt ◽  
Louise P. Chini ◽  
Ritvik Sahajpal ◽  
Julia Pongratz ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Land Cover Change ◽  
Human Impacts ◽  
Land Use Changes ◽  
Remote Sensing Data ◽  
Transition Rule ◽  
The Relationship ◽  
Earth System Models

Abstract. Information on historical land-cover change is important for understanding human impacts on the environment. Over the last decade, global models have characterized historical land-use changes, but few have been able to relate these changes with corresponding changes in land-cover. Utilizing the latest global land-use change data, we make several assumptions about the relationship between land-use and land-cover change, and evaluate each scenario with remote sensing data to identify optimal fit. The resulting transition rule can guide the incorporation of land-cover information within earth system models.

scholarly journals Si cycling in transition zones: a study of Si isotopes and biogenic silica accumulation in the Chesapeake Bay through the Holocene

2019 ◽  
Vol 146 (2) ◽  
pp. 145-170
Author(s):  
Carla K. M. Nantke ◽  
Patrick J. Frings ◽  
Johanna Stadmark ◽  
Markus Czymzik ◽  
Daniel J. Conley
Keyword(s):  
Land Use ◽  
Chesapeake Bay ◽  
Biogenic Silica ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Sediment Cores ◽  
Global Scale ◽  
Silicon Isotope ◽  
Coastal Zones ◽  
Local Climate

AbstractSi fluxes from the continents to the ocean are a key element of the global Si cycle. Due to the ability of coastal ecosystems to process and retain Si, the ‘coastal filter’ has the potential to alter Si fluxes at a global scale. Coastal zones are diverse systems, sensitive to local environmental changes, where Si cycling is currently poorly understood. Here, we present the first palaeoenvironmental study of estuarine biogenic silica (BSi) fluxes and silicon isotope ratios in diatoms (δ30Sidiatom) using hand-picked diatom frustules in two sediment cores (CBdist and CBprox) from the Chesapeake Bay covering the last 12000 and 8000 years, respectively. Constrained by the well-understood Holocene evolution of the Chesapeake Bay, we interpret variations in Si cycling in the context of local climate, vegetation and land use changes. δ30Sidiatom varies between + 0.8 and + 1.7‰ in both sediment cores. A Si mass balance for the Chesapeake Bay suggests much higher rates of Si retention (~ 90%) within the system than seen in other coastal systems. BSi fluxes for both sediment cores co-vary with periods of sea level rise (between 9500 and 7500 a BP) and enhanced erosion due to deforestation (between 250 and 50 a BP). However, differences in δ30Sidiatom and BSi flux between the sites emphasize the importance of the seawater/freshwater mixing ratios and locally variable Si inputs from the catchment. Further, we interpret variations in δ30Sidiatom and the increase in BSi fluxes observed since European settlement (~ 250 a BP) to reflect a growing human influence on the Si cycle in the Chesapeake Bay. Thereby, land use change, especially deforestation, in the catchment is likely the major mechanism.

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