scholarly journals Dominant species determine ecosystem stability across scales in Inner Mongolian grassland

2021 ◽  
Author(s):  
Yonghui Wang ◽  
Shao-Peng Wang ◽  
Liqing Zhao ◽  
Cunzhu Liang ◽  
Bailing Miao ◽  
...  

There is an urgent need to extend knowledge on ecosystem temporal stability to larger spatial scales because presently available local-scale studies generally do not provide effective guide for management and conservation decisions at the level of an entire region with diverse plant communities. We investigated temporal stability of plant biomass production across spatial scales and hierarchical levels of community organization and analyzed impacts of dominant species, species diversity and climatic factors using a multi-site survey of Inner Mongolian grassland. We found that temporal stability at a large spatial scale, i.e. a large area aggregating multiple local communities, was related to temporal stability of and asynchrony among spatially separated local communities and large-scale population dynamics of dominant species, yet not to species richness. Additionally, a lower mean and higher variation of yearly precipitation destabilized communities at local and large scales by destabilizing dominant species population dynamics. We argue that, for semi-arid temperate grassland, dynamics and precipitation responses of dominant species and asynchrony among local communities stabilize ecosystems at large spatial scales. Our results indicate that reduced amounts and increased variation of precipitation may present key threats to the sustainable provision of biological products and services to human well-being in this region.

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 141
Author(s):  
Firoza Akhter ◽  
Maurizio Mazzoleni ◽  
Luigia Brandimarte

In this study, we explore the long-term trends of floodplain population dynamics at different spatial scales in the contiguous United States (U.S.). We exploit different types of datasets from 1790–2010—i.e., decadal spatial distribution for the population density in the US, global floodplains dataset, large-scale data of flood occurrence and damage, and structural and nonstructural flood protection measures for the US. At the national level, we found that the population initially settled down within the floodplains and then spread across its territory over time. At the state level, we observed that flood damages and national protection measures might have contributed to a learning effect, which in turn, shaped the floodplain population dynamics over time. Finally, at the county level, other socio-economic factors such as local flood insurances, economic activities, and socio-political context may predominantly influence the dynamics. Our study shows that different influencing factors affect floodplain population dynamics at different spatial scales. These facts are crucial for a reliable development and implementation of flood risk management planning.


2020 ◽  
Vol 24 (5) ◽  
pp. 2711-2729 ◽  
Author(s):  
Joseph L. Gutenson ◽  
Ahmad A. Tavakoly ◽  
Mark D. Wahl ◽  
Michael L. Follum

Abstract. Large-scale hydrologic forecasts should account for attenuation through lakes and reservoirs when flow regulation is present. Globally generalized methods for approximating outflow are required but must contend with operational complexity and a dearth of information on dam characteristics at global spatial scales. There is currently no consensus on the best approach for approximating reservoir release rates in large spatial scale hydrologic forecasting, particularly at diurnal time steps. This research compares two parsimonious reservoir routing methods at daily steps: Döll et al. (2003) and Hanasaki et al. (2006). These reservoir routing methods have been previously implemented in large-scale hydrologic modeling applications and have been typically evaluated seasonally. These routing methods are compared across 60 reservoirs operated by the U.S. Army Corps of Engineers. The authors vary empirical coefficients for both reservoir routing methods as part of a sensitivity analysis. The method proposed by Döll et al. (2003) outperformed that presented by Hanasaki et al. (2006) at a daily time step and improved model skill over most run-of-the-river conditions. The temporal resolution of the model influences model performances. The optimal model coefficients varied across the reservoirs in this study and model performance fluctuates between wet years and dry years, and for different configurations such as dams in series. Overall, the method proposed by Döll et al. (2003) could enhance large-scale hydrologic forecasting, but can be subject to instability under certain conditions.


2015 ◽  
Vol 93 (7) ◽  
pp. 515-519 ◽  
Author(s):  
Nancy E. Roney ◽  
Anna Kuparinen ◽  
Jeffrey A. Hutchings

The abundance–occupancy relationship is one of the most well-examined relationships in ecology. At the species level, a positive association has been widely documented. However, until recently, research on the nature of this relationship at broad taxonomic and spatial scales has been limited. Here, we perform a comparative analysis of 12 taxonomic groups across a large spatial scale (Canada), using data on Canadian species at risk: amphibians, arthropods, birds, freshwater fishes, lichens, marine fishes, marine mammals, molluscs, mosses, reptiles, terrestrial mammals, and vascular plants. We find a significantly positive relationship in all taxonomic groups with the exception of freshwater fishes (negative association) and lichens (no association). In general, our work underscores the strength and breadth of this apparently fundamental relationship and provides insight into novel applications for large-scale population dynamics. Further development of species-independent abundance–occupancy relationships, or those of a similar nature, might well prove instrumental in serving as starting points for developing species-independent reference points and recovery strategies.


Author(s):  
Giles Jackson ◽  
Megan Epler Wood

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Environmental Science. Please check back later for the full article. Ecotourism is an evolving field that originated in the 1980s, when leading conservationists explored and wrote seminal papers on how tourism could contribute to the conservation of natural areas. Hector Ceballos Lascurain coined the first definition, and the International Union for Conservation of Nature, the World Wildlife Fund, Conservation International, and The Nature Conservancy all undertook research and documentation of the benefits and potential risks of ecotourism in the 1990s. The International Ecotourism Society, founded in 1990, brought together conservation organizations and businesses to create the first definition that was globally accepted in short form: Responsible travel to natural areas that conserves the environment and sustains the well-being of local people. Small group tour operators flourished during the 1990s, bringing travelers to a growing number of natural areas worldwide, together with top guiding, high-caliber interpretation, and strong ethical contributions to local wellbeing. Many important micro, small, and medium sized enterprises were founded in high biodiversity regions of Latin America, Asia, Africa, Antarctica, Australia, and throughout the Pacific Islands and the Caribbean, offering life-changing experiences while helping build conservation economies and inspiring positive action. In 2015, nature-based tourism was estimated to have an economic value worldwide of hundreds of billions of dollars annually in protected areas alone, driven by the growing need of a rapidly urbanizing world to experience and reconnect with wild nature. However, this growth has not resulted in growing budgets to safeguard and manage natural areas, which are increasingly under threat. Scientific concerns that poor business practices under the guise of ecotourism might irreversibly damage fragile natural areas have led the conservation community to de-emphasize ecotourism as a conservation tool in favor of business certification. But these efforts have reached only a small percentage of the corporate sector of the eight trillion dollar global tourism industry. Although the net economic, social, and environmental contributions of ecotourism have not been fully accounted for, the research to date has confirmed the conservation value of ecotourism—among the first examples of social enterprise. One well-documented case is Wilderness Safaris, an $89 million company operating in 58 destinations in Southern Africa in 2015, which reinvests at least 5% of its gross profit (before taxation and depreciation) to help protect the natural assets and support local communities on which the business depends. This example suggests that ecotourism can yield benefits for the conservation of biodiversity and can benefit local communities on a large scale. To increase ecotourism’s role in sustainable development, more businesses will need to scale up, and government management of tourism will require improved impact measurements, updated regulatory strategies, and effective policy mechanisms to garner a greater portion of tourism revenue.


2017 ◽  
Vol 46 (4) ◽  
pp. 648-667 ◽  
Author(s):  
Yunxiao Dang ◽  
Guanpeng Dong ◽  
Yu Chen ◽  
Kelvyn Jones ◽  
Wenzhong Zhang

Existing literature has examined the determinants of subjective well-being in China from the social, economic and psychological perspectives. Very few studies explore the impacts of residential environment on subjective well-being. Drawing on a large scale questionnaire survey in Beijing, this paper investigates the role of residential environment by decomposing the variations of subjective well-being at fine-grained spatial scales, i.e. district and neighbourhood levels. A bivariate response binomial multilevel model is employed to assess the relative importance of geographical contexts and individual characteristics, in particular, the household registration (hukou) status, in influencing subjective well-being. The results show significant heterogeneities in subjective well-being among districts and neighbourhoods. Neighbourhood types are significantly correlated with subjective well-being, with residents in commercial housing neighbourhoods reporting higher levels of subjective well-being than those in work-unit and affordable housing neighbourhoods. However, the impacts of neighbourhood types are not uniformly experienced by people with different hukou status. Migrants tend to express lower levels of subjective well-being than local residents. Such disparities are more pronounced in urban villages compared with other neighbourhoods.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yann Hautier ◽  
Pengfei Zhang ◽  
Michel Loreau ◽  
Kevin R. Wilcox ◽  
Eric W. Seabloom ◽  
...  

Abstract Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant diversity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species composition within sites (higher beta diversity) have greater spatial asynchrony of productivity among communities, resulting in greater stability at the larger scale (gamma stability). Importantly, fertilization consistently weakens the contribution of plant diversity to both of these stabilizing mechanisms, thus diminishing the positive effect of biodiversity on stability at differing spatial scales. Our findings suggest that preserving grassland functional stability requires conservation of plant diversity within and among ecological communities.


2019 ◽  
Author(s):  
Michael J. Plank ◽  
Matthew J. Simpson ◽  
Rachelle N. Binny

AbstractLocal interactions among individual members of a population can generate intricate small-scale spatial structure, which can strongly influence population dynamics. The two-way interplay between local interactions and population dynamics is well understood in the relatively simple case where the population occupies a fixed domain with a uniform average density. However, the situation where the average population density is spatially varying is less well understood. This situation includes ecologically important scenarios such as species invasions, range shifts, and moving population fronts. Here, we investigate the dynamics of the spatial stochastic logistic model in a scenario where an initially confined population subsequently invades new, previously unoccupied territory. This simple model combines density-independent proliferation with dispersal, and density-dependent mortality via competition with other members of the population. We show that, depending on the spatial scales of dispersal and competition, either a clustered or a regular spatial structure develops over time within the invading population. In the short-range dispersal case, the invasion speed is significantly lower than standard predictions of the mean-field model. We conclude that mean-field models, even when they account for non-local processes such as dispersal and competition, can give misleading predictions for the speed of a moving invasion front.


2021 ◽  
Author(s):  
Kaique Santos Alves ◽  
Lisa Ann Rothmann ◽  
Emerson Medeiros Del Ponte

Huanglongbing (HLB) is one of the most important diseases for the citriculture in the world. Knowledge of climatic factors linked to HLB risk at the large spatial scale is limited. We gathered HLB presence/absence data from official surveys conducted in the state of Minas Gerais, Brazil, for 13 years. The total count of orange and mandarin orchards, and mean orchard area, normalized to a spatial grid of 60 cells (55 x 55 km), were derived from the same database. The monthly climate normal (1984 to 2013) on rainfall, mean temperature, and wind speed were split into rainy (September to April) and dry (May to August) seasons (annual summary was retained) were also obtained for each grid cell. Two hierarchical Bayesian modeling approaches were evaluated both based on the integrated nested Laplace approximation methodology. The first, the climate covariates model (CC model), used orchard, climate, and the spatial effect as covariates. The second, principal components (PC model), used the first three components from a PCA of all variables and the spatial effect as covariates. Both models showed an inverse relationship between posterior prevalence and mean temperature during dry season across the grid cells. Annual wind speed, as well as annual and rainy season rainfall, contributed significantly towards HLB risk, in the CC and PC models, respectively. A partial influence of neighboring regions on HLB risk was observed. These results should assist policymakers in defining regions at HLB risk and monitoring strategies to avoid further spread in the target region.


Author(s):  
Özlem Edizel ◽  
Graeme Evans

This chapter focuses on the application of cultural ecosystems mapping as a participatory, co-produced visualisation and engagement method. Using a case study of the Lee Valley in London, it investigates how local communities relate to and engage with urban water environments using arts and humanities methodologies. Engaging people with issues around cultural ecosystem services through the interaction with large-scale maps of the local area helps to ground the more abstract issues of identity, connectivity, sense of place, emotional attachment, and spirituality, as well as overcome the traditional barriers to participation and inclusion at various spatial scales. Cultural mapping in particular helps to articulate the spatial and historical relationships and triggers debate over connectivity, governance, environmental justice, and both environmental and social change.


Author(s):  
Q. Q. Chen ◽  
Shaopeng Wang ◽  
Eric Seabloom ◽  
Andrew MacDougall ◽  
Elizabeth Borer ◽  
...  

Nutrients and herbivores have independent effects on the temporal stability of aboveground biomass in grasslands; however, their joint effects may not be additive and may also depend on spatial scales. In an experiment adding nutrients and excluding herbivores in 34 globally distributed grasslands, we found that nutrients and herbivores mainly had additive effects. Nutrient addition consistently reduced stability at the local and larger spatial scales (aggregated local communities), while herbivore exclusion weakly reduced stability at these scales. Moreover, nutrient addition reduced stability primarily by causing changes in local community composition over time and by reducing local species richness and evenness. In contrast, herbivore exclusion weakly reduced stability at the larger scale mainly by decreasing asynchronous dynamics among local communities, but also by weakly decreasing local species richness. Our findings indicate disentangling the influences of processes operating at different spatial scales may improve conservation and management in stabilizing grassland biomass.


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