scholarly journals Traversing the Wasteland: A Framework for Assessing Ecological Threats to Drylands

BioScience ◽  
2019 ◽  
Vol 70 (1) ◽  
pp. 35-47 ◽  
Author(s):  
David L Hoover ◽  
Brandon Bestelmeyer ◽  
Nancy B Grimm ◽  
Travis E Huxman ◽  
Sasha C Reed ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Global Change ◽  
Soil Fertility ◽  
Present Article ◽  
Ecosystem Function ◽  
Critical Role ◽  
Tipping Points ◽  
Negative Perceptions ◽  
Dryland Ecosystems ◽  
Variable Precipitation

Abstract Drylands cover 41% of the Earth's terrestrial surface, play a critical role in global ecosystem function, and are home to over two billion people. Like other biomes, drylands face increasing pressure from global change, but many of these ecosystems are close to tipping points, which, if crossed, can lead to abrupt transitions and persistent degraded states. Their limited but variable precipitation, low soil fertility, and low productivity have given rise to a perception that drylands are wastelands, needing societal intervention to bring value to them. Negative perceptions of drylands synergistically combine with conflicting sociocultural values regarding what constitutes a threat to these ecosystems. In the present article, we propose a framework for assessing threats to dryland ecosystems and suggest we must also combat the negative perceptions of drylands in order to preserve the ecosystem services that they offer.

scholarly journals Global ecosystem thresholds driven by aridity

Science ◽  
2020 ◽  
Vol 367 (6479) ◽  
pp. 787-790 ◽  
Author(s):  
Miguel Berdugo ◽  
Manuel Delgado-Baquerizo ◽  
Santiago Soliveres ◽  
Rocío Hernández-Clemente ◽  
Yanchuang Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Soil Fertility ◽  
Plant Cover ◽  
Plant Productivity ◽  
Abrupt Changes ◽  
Dryland Ecosystems ◽  
Negative Impacts ◽  
Ecosystem Changes ◽  
Three Phases

Aridity, which is increasing worldwide because of climate change, affects the structure and functioning of dryland ecosystems. Whether aridification leads to gradual (versus abrupt) and systemic (versus specific) ecosystem changes is largely unknown. We investigated how 20 structural and functional ecosystem attributes respond to aridity in global drylands. Aridification led to systemic and abrupt changes in multiple ecosystem attributes. These changes occurred sequentially in three phases characterized by abrupt decays in plant productivity, soil fertility, and plant cover and richness at aridity values of 0.54, 0.7, and 0.8, respectively. More than 20% of the terrestrial surface will cross one or several of these thresholds by 2100, which calls for immediate actions to minimize the negative impacts of aridification on essential ecosystem services for the more than 2 billion people living in drylands.

scholarly journals Does agricultural intensification cause tipping points in ecosystem services?

2021 ◽  
Author(s):  
Stephen C. L. Watson ◽  
Adrian C. Newton ◽  
Lucy E. Ridding ◽  
Paul M. Evans ◽  
Steven Brand ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Agricultural Intensification ◽  
Spatial Dynamics ◽  
Policy Option ◽  
List Type ◽  
Tipping Points ◽  
Software Models ◽  
Non Linear ◽  
Study Interval ◽  
The Impact

Abstract Context Agricultural intensification is being widely pursued as a policy option to improve food security and human development. Yet, there is a need to understand the impact of agricultural intensification on the provision of multiple ecosystem services, and to evaluate the possible occurrence of tipping points. Objectives To quantify and assess the long-term spatial dynamics of ecosystem service (ES) provision in a landscape undergoing agricultural intensification at four time points 1930, 1950, 1980 and 2015. Determine if thresholds or tipping points in ES provision may have occurred and if there are any detectable impacts on economic development and employment. Methods We used the InVEST suite of software models together with a time series of historical land cover maps and an Input–Output model to evaluate these dynamics over an 85-year period in the county of Dorset, southern England. Results Results indicated that trends in ES were often non-linear, highlighting the potential for abrupt changes in ES provision to occur in response to slight changes in underlying drivers. Despite the fluctuations in provision of different ES, overall economic activity increased almost linearly during the study interval, in line with the increase in agricultural productivity. Conclusions Such non-linear thresholds in ES will need to be avoided in the future by approaches aiming to deliver sustainable agricultural intensification. A number of positive feedback mechanisms are identified that suggest these thresholds could be considered as tipping points. However, further research into these feedbacks is required to fully determine the occurrence of tipping points in agricultural systems.

scholarly journals Potential of Alnus acuminata based agroforestry for carbon sequestration and other ecosystem services in Rwanda

2021 ◽  
Author(s):  
Athanase R. Cyamweshi ◽  
Shem Kuyah ◽  
Athanase Mukuralinda ◽  
Catherine W. Muthuri
Keyword(s):  
Ecosystem Services ◽  
Carbon Sequestration ◽  
Soil Fertility ◽  
Tree Age ◽  
Average Height ◽  
Total Biomass ◽  
Biomass Carbon ◽  
Alnus Acuminata ◽  
Sequestration Potential ◽  
Old Trees

AbstractAlnus acuminata Kunth. (alnus) is widely used in agroforestry systems across the globe and is believed to provide multiple ecosystem services; however, evidence is lacking in agroforestry literature to support the perceived benefits, particularly in Rwanda. To understand carbon sequestration potential and other benefits of alnus, a household survey, tree inventory and destructive sampling were conducted in north-western Rwanda. Over 75% of the respondents had alnus trees in their farms. The trees provide stakes for climbing beans, firewood and timber. They also improve soil fertility and control soil erosion. Farmers had between 130 and 161 alnus trees per hectare with an average height of 7.7 ± 0.59 m and diameter at breast height of 16.3 ± 1.39 cm. The largest biomass proportion was found in stems (70.5%) while branches and leaves stock about 16.5 and 13% of the total biomass, respectively. At farm level, aboveground biomass of alnus trees was estimated to be 27.2 ± 0.7 Mg ha−1 representing 13.6 Mg of carbon (C) per hectare. Biomass carbon increased with tree size, from 7.1 ± 0.2 Mg C ha−1 in 3 years old trees to 34.4 ± 2.2 Mg C ha−1 in 10 years old trees. The converse was observed with elevation; biomass carbon decreased with increasing elevation from 21.4 ± 1.29 Mg C ha−1 at low (2011–2110 m) to 9.6 ± 0.75 Mg C ha−1 in the high elevation (> 2510 m). In conclusion, alnus agroforestry significantly contributes to carbon sequestration, although the magnitude of these benefits varies with tree age and elevation. Planting alnus trees on farms can meet local needs for stakes for climbing beans, wood and soil fertility improvement, as well as the global need for regulation of climate change.

scholarly journals OVERCROWDED PRISONS IN PAKISTAN: UNDERSTANDING THE CRITICAL ROLE OF PROBATION, PAROLE OFFICERS AND COURTS

2021 ◽  
Vol 03 (01) ◽  
pp. 40-47
Author(s):  
Mukhtyar Nabi ◽  
◽  
Saddam Hussain ◽  
Muhammad Kamran ◽  
◽  
...  
Keyword(s):  
Present Article ◽  
Behavioral Problems ◽  
High Frequency ◽  
Critical Role ◽  
Prison System ◽  
Probation Officers ◽  
Parole Officers ◽  
The World

Prison is a place for rehabilitation of offenders in every country of the world. The present study has tried to explore the present-day situation of the prison system of Pakistan and discuss its overcrowding condition in all four provinces. There are total 120 prisons in the country which hold authorized space for not more than 57,712 prisoners, but the number of inmates is 77,275, which is far away from the authorized space. This congested prison system not only creates hurdles in rehabilitation of prisoners but makes them more criminal by mixing of low and high frequency offenders. It also leads to various health and behavioral problems. Rehabilitation is only possible if there is balance in authorized and available prisoners in the prisons. The present article has come up with some viable suggestion for concerned authorities that can better perform their duty in eradication of this problem. The authors discussed the role of parole and probation officers in the elimination of these numbers in prison. The majority of the prisoners in our prisons are under-trail, thus the role of the judiciary has also been explored in balancing the incarceration ratio in prisons. Keywords: Prison System, Overcrowded Prisons, Parole and Probation, Judiciary, Courts, Pakistan

scholarly journals A 21st Century Vision for Neotropical Snake Systematics

2018 ◽  
Vol 1 (1) ◽  
pp. 58
Author(s):  
Robert Alexander Pyron
Keyword(s):  
Species Richness ◽  
Natural History ◽  
Global Change ◽  
South America ◽  
Ecosystem Function ◽  
Museum Specimens ◽  
Fine Grained ◽  
The Past ◽  
The Caribbean ◽  
Recent Synthesis

We live in an unprecedented age for systematics and biodiversity studies. Ongoing global change is leading to a future with reduced species richness and ecosystem function (Pereira, Navarro, & Martins, 2012). Yet, we know more about biodiversity now than at any time in the past. For squamates in particular, we have range maps for all species (Roll et al., 2017), phylogenies containing estimates for all species (Tonini, Beard, Ferreira, Jetz, & Pyron, 2016), and myriad ecological and natural-history datasets for a large percentage of species (Meiri et al., 2013; Mesquita et al., 2016). For neotropical snakes, a recent synthesis of museum specimens and verified localities offers a fine-grained perspective on their ecogeographic distribution in Central and South America, and the Caribbean (Guedes et al., 2018).

Biodiversity–ecosystem function

2021 ◽  
pp. 137-146
Author(s):  
Simon F. Thrush ◽  
Judi E. Hewitt ◽  
Conrad A. Pilditch ◽  
Alf Norkko
Keyword(s):  
Ecosystem Services ◽  
Ecosystem Function ◽  
Functional Performance ◽  
Biodiversity Loss ◽  
Soft Sediment ◽  
Multiple Functions ◽  
Service Relationships ◽  
Biodiversity And Ecosystem Function ◽  
Up Scaling

This chapter looks at the links between biodiversity and ecosystem function in soft sediments to help understand the implications of biodiversity loss on ecosystem services. The chapter contains a focus on the challenges in developing real-world tests of biodiversity–ecosystem function (BEF) relationships. The various forms of BEF relationships, their implications and the different elements of biodiversity that link to function are described. Given the multiple functions that occur in soft-sediment ecosystems, this has important implications for the assessment and implications of BEF relationships and functional performance in the up-scaling of BEF relationships. The role of BEF in underpinning many ecosystem services and the interconnections in biodiversity and ecosystem service relationships close out the chapter.

scholarly journals Agricultural diversification promotes multiple ecosystem services without compromising yield

2020 ◽  
Vol 6 (45) ◽  
pp. eaba1715 ◽  
Author(s):  
Giovanni Tamburini ◽  
Riccardo Bommarco ◽  
Thomas Cherico Wanger ◽  
Claire Kremen ◽  
Marcel G. A. van der Heijden ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Nutrient Cycling ◽  
Soil Fertility ◽  
Pest Control ◽  
Crop Yields ◽  
Cropping Systems ◽  
Context Dependency ◽  
Water Regulation ◽  
Trade Offs ◽  
The Impact

Enhancing biodiversity in cropping systems is suggested to promote ecosystem services, thereby reducing dependency on agronomic inputs while maintaining high crop yields. We assess the impact of several diversification practices in cropping systems on above- and belowground biodiversity and ecosystem services by reviewing 98 meta-analyses and performing a second-order meta-analysis based on 5160 original studies comprising 41,946 comparisons between diversified and simplified practices. Overall, diversification enhances biodiversity, pollination, pest control, nutrient cycling, soil fertility, and water regulation without compromising crop yields. Practices targeting aboveground biodiversity boosted pest control and water regulation, while those targeting belowground biodiversity enhanced nutrient cycling, soil fertility, and water regulation. Most often, diversification practices resulted in win-win support of services and crop yields. Variability in responses and occurrence of trade-offs highlight the context dependency of outcomes. Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.

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