Manipulation of Ecosystem Dynamics on Reconstructed Semiarid Lands

2019 ◽  
pp. 162-204
Author(s):  
Edward J. DePuit ◽  
Edward F. Redente
Keyword(s):  
Ecosystem Dynamics

CLIMATE AND HYDROLOGIC DRIVERS OF LAKE ECOSYSTEM DYNAMICS IN AN ALPINE CATCHMENT, COLORADO, USA

2016 ◽  
Author(s):  
Diane M. McKnight ◽  
◽  
Eric Sokol ◽  
Mark Williams ◽  
Katherina Hell ◽  
...  
Keyword(s):  
Ecosystem Dynamics ◽  
Lake Ecosystem

USING FOOD WEBS TO EXAMINE ECOSYSTEM DYNAMICS DURING BIOTIC INVASIONS IN LATE ORDOVICIAN SHALLOW MARINE COMMUNITIES

2016 ◽  
Author(s):  
Hannah L. Kempf ◽  
◽  
Ashley A. Dineen ◽  
Peter D. Roopnarine ◽  
Carrie L. Tyler
Keyword(s):  
Food Webs ◽  
Late Ordovician ◽  
Ecosystem Dynamics ◽  
Shallow Marine ◽  
Marine Communities

scholarly journals Using GEDI Waveforms for Improved TanDEM-X Forest Height Mapping: A Combined SINC + Legendre Approach

2021 ◽  
Vol 13 (15) ◽  
pp. 2882
Author(s):  
Hao Chen ◽  
Shane R. Cloude ◽  
Joanne C. White
Keyword(s):  
High Resolution ◽  
Forest Canopy ◽  
Test Site ◽  
Convergent Series ◽  
Canopy Height ◽  
Ecosystem Dynamics ◽  
Sinc Function ◽  
Vertical Profiles ◽  
Legendre Series ◽  
Vertical Profiling

In this paper, we consider a new method for forest canopy height estimation using TanDEM-X single-pass radar interferometry. We exploit available information from sample-based, space-borne LiDAR systems, such as the Global Ecosystem Dynamics Investigation (GEDI) sensor, which offers high-resolution vertical profiling of forest canopies. To respond to this, we have developed a new extended Fourier-Legendre series approach for fusing high-resolution (but sparsely spatially sampled) GEDI LiDAR waveforms with TanDEM-X radar interferometric data to improve wide-area and wall-to-wall estimation of forest canopy height. Our key methodological development is a fusion of the standard uniform assumption for the vertical structure function (the SINC function) with LiDAR vertical profiles using a Fourier-Legendre approach, which produces a convergent series of approximations of the LiDAR profiles matched to the interferometric baseline. Our results showed that in our test site, the Petawawa Research Forest, the SINC function is more accurate in areas with shorter canopy heights (<~27 m). In taller forests, the SINC approach underestimates forest canopy height, whereas the Legendre approach avails upon simulated GEDI forest structural vertical profiles to overcome SINC underestimation issues. Overall, the SINC + Legendre approach improved canopy height estimates (RMSE = 1.29 m) compared to the SINC approach (RMSE = 4.1 m).

scholarly journals Ecosystem dynamics: exploring the interplay within fintech entrepreneurial ecosystems

2021 ◽  
Author(s):  
Ahmad Alaassar ◽  
Anne-Laure Mention ◽  
Tor Helge Aas
Keyword(s):  
New Ventures ◽  
Ecosystem Dynamics ◽  
Resource Exploitation ◽  
Cultural Perspective ◽  
Structured Interviews ◽  
Opportunity Identification ◽  
Entrepreneurial Ecosystems ◽  
Regulatory Dynamics ◽  
Financial Technology

AbstractScholars and practitioners continue to recognize the crucial role of entrepreneurial ecosystems (EEs) in creating a conducive environment for productive entrepreneurship. Although EEs are fundamentally interaction systems of hierarchically independent yet mutually dependent actors, few studies have investigated how interactions among ecosystem actors drive the entrepreneurial process. Seeking to address this gap, this paper explores how ecosystem actor interactions influence new ventures in the financial technology (fintech) EE of Singapore. Guided by an EE framework and the use of an exploratory-abductive approach, empirical data from semi-structured interviews is collected and analyzed. The findings reveal four categories representing both the relational perspective, which features interaction and intermediation dynamics, and the cultural perspective, which encompasses ecosystem development and regulatory dynamics. These categories help explain how and why opportunity identification and resource exploitation are accelerated or inhibited for entrepreneurs in fintech EEs. The present study provides valuable contributions to scholars and practitioners interested in EEs and contributes to the academic understanding of the emerging fintech phenomenon.

scholarly journals Effects of Infectious Diseases on Population Dynamics of Marine Organisms in Chesapeake Bay

2021 ◽  
Author(s):  
Jerelle A. Jesse ◽  
M. Victoria Agnew ◽  
Kohma Arai ◽  
C. Taylor Armstrong ◽  
Shannon M. Hood ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Infectious Diseases ◽  
Chesapeake Bay ◽  
Eastern Oyster ◽  
Marine Organisms ◽  
Ecosystem Dynamics ◽  
Climate Change Effects ◽  
Pathogen Dynamics ◽  
Growth And Reproduction

AbstractDiseases are important drivers of population and ecosystem dynamics. This review synthesizes the effects of infectious diseases on the population dynamics of nine species of marine organisms in the Chesapeake Bay. Diseases generally caused increases in mortality and decreases in growth and reproduction. Effects of diseases on eastern oyster (Crassostrea virginica) appear to be low in the 2000s compared to effects in the 1980s–1990s. However, the effects of disease were not well monitored for most of the diseases in marine organisms of the Chesapeake Bay, and few studies considered effects on growth and reproduction. Climate change and other anthropogenic effects are expected to alter host-pathogen dynamics, with diseases of some species expected to worsen under predicted future conditions (e.g., increased temperature). Additional study of disease prevalence, drivers of disease, and effects on population dynamics could improve fisheries management and forecasting of climate change effects on marine organisms in the Chesapeake Bay.

scholarly journals Seasonal biological carryover dominates northern vegetation growth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xu Lian ◽  
Shilong Piao ◽  
Anping Chen ◽  
Kai Wang ◽  
Xiangyi Li ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Growing Season ◽  
Ecosystem Dynamics ◽  
Environmental Drivers ◽  
Subsequent Growth ◽  
Ecosystem Models ◽  
Carryover Effect ◽  
Vegetation Growth ◽  
Sequestration Potential ◽  
Future Warming

AbstractThe state of ecosystems is influenced strongly by their past, and describing this carryover effect is important to accurately forecast their future behaviors. However, the strength and persistence of this carryover effect on ecosystem dynamics in comparison to that of simultaneous environmental drivers are still poorly understood. Here, we show that vegetation growth carryover (VGC), defined as the effect of present states of vegetation on subsequent growth, exerts strong positive impacts on seasonal vegetation growth over the Northern Hemisphere. In particular, this VGC of early growing-season vegetation growth is even stronger than past and co-occurring climate on determining peak-to-late season vegetation growth, and is the primary contributor to the recently observed annual greening trend. The effect of seasonal VGC persists into the subsequent year but not further. Current process-based ecosystem models greatly underestimate the VGC effect, and may therefore underestimate the CO2 sequestration potential of northern vegetation under future warming.

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