Bottom-up and top-down approaches to assess multiple stressors over large geographic areas

2000 ◽  
Vol 19 (4) ◽  
pp. 1066-1075 ◽  
Author(s):  
Scott D. Dyer ◽  
Charlotte White-Hull ◽  
Gregory J. Carr ◽  
Eric P. Smith ◽  
Xinhao Wang
Keyword(s):  
Multiple Stressors ◽  
Top Down ◽  
Bottom Up

SYSTEMLINK - a new project on the effects of stressors across ecosystem barriers

2020 ◽  
Author(s):  
Johanna Girardi ◽  
Ralf Schulz ◽  
Mirco Bundschuh ◽  
Martin H. Entling ◽  
Eva Kröner ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Multiple Stressors ◽  
Research Training ◽  
Terrestrial Ecosystems ◽  
Water Source ◽  
Training Group ◽  
Landscape Scale ◽  
Top Down ◽  
Bottom Up ◽  
Riparian Plants

<p>The propagation of environmental stressors from water (source) to land (sink) in aquatic-terrestrial meta-ecosystems, has not been intensively investigated. The other way around has been in the focus of linking terrestrial and aquatic domains. To start bridging that gap, SYSTEMLINK, a DFG Research Training Group, addresses the bottom-up and top-down mediated interactions in terrestrial ecosystems, which origin from anthropogenic impairments on aquatic ecosystems. Micropollutants (fungicides and insecticides) as well as invasive species (riparian plants and invertebrates) are considered as crucial forms of multiple stressors in disturbed aquatic ecosystems. SYSTEMLINK will examine the general hypotheses that 1) invasive invertebrates and insecticide exposure and 2) invasive riparian plants and fungicide exposure cause top-down and bottom-up mediated responses in terrestrial ecosystems, respectively. Collaborative experiments in replicated outdoor aquatic-terrestrial mesocosms (site-scale) amended by joint pot experiments (batch-scale), field studies (landscape-scale), and modelling are used to test these general and several more specific hypotheses. The experimental setups will all represent a multi-stress environment and will be derived from the landscape scale. The regular combination of several scales will allow to overcome scale-specific limitations and to ensure both cause-effect quantification and the environmental relevance of the results. Ultimately, SYSTEMLINK thrives to increase our knowledge on effect translation across ecosystem boundaries. By combining biological subsidies and biogeochemical fluxes we will be able to quantify their relative importance. Furthermore, we will closely incorporate the often separated aquatic and terrestrial research areas.</p>

scholarly journals Environmental Pressures on Top-Down and Bottom-Up Forces in Coastal Ecosystems

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 444
Author(s):  
Michael J. Blum
Keyword(s):  
Multiple Stressors ◽  
Negative Impact ◽  
Plant Stress ◽  
Coastal Ecosystems ◽  
Freshwater Ecosystems ◽  
Nitrogen Enrichment ◽  
Top Down ◽  
Bottom Up ◽  
Environmental Pressures ◽  
Elevated Salinity

Global change is manifesting new and potent pressures that may determine the relative influence of top-down and bottom-up forces on the productivity of plants that undergird coastal ecosystems. Here, I present a meta-analysis conducted to assess how herbivory, nitrogen enrichment, and elevated salinity influence plant productivity according to the salinity regimes of coastal ecosystems. An examination of 99 studies representing 288 effect sizes across 76 different plant species revealed that elevated salinity negatively affected productivity across all environments, but particularly in freshwater ecosystems. Nitrogen enrichment, on the other hand, positively affected productivity. In agreement with the plant stress hypothesis, herbivory had the greatest negative impact in saline habitats. This trend, however, appears to reverse with nitrogen enrichment, with maximum losses to herbivory occurring in brackish habitats. These findings demonstrate that multiple stressors can yield complex, and sometimes opposite outcomes to those arising from individual stressors. This study also suggests that trophic interactions will likely shift as coastal ecosystems continue to experience nutrient enrichment and sea level rise.

Psychology and Culture: Top Down Versus Bottom Up?

PsycCRITIQUES ◽  
2005 ◽  
Vol 50 (19) ◽  
Author(s):  
Michael Cole
Keyword(s):  
Top Down ◽  
Bottom Up

Optimalisasi Ekonomi Syariah Untuk Peningkatan Kesejahteraan Masyarakat Dalam Pengentasan Kemiskinan Mewujudkan Goodgovernance

2019 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Sadari Sadari ◽  
Nurhidayat Nurhidayat ◽  
Rafiqah Rafiqah
Keyword(s):  
Top Down ◽  
Bottom Up

Humanisme religius telah mengantarkan pada era kesadaran bahwa peradaban manusia harus memiliki dua arus yang saling menunjang. Selama ini arus balik dalam bidang ekonomi hanya menonjolkan arus balik vertikal atas kebawah (model top down) yang didominasi oleh sistem ekonomi kapitalis dan sosialis, sedangkan di sisi lain mengesampingkan arus balik vertikal dari bawah ke atas (model bottom up) yang didominasi oleh sistem ekonomi syariah, sehingga dampaknya adalah adanya kesenjangan ekonomi yang sangat tajam. Paper ini mewujudkan peran penting, yakni menghubungkan dua arus tersebut secara timbal-balik, yakni mempertemukan arus pertama dengan arus balik kedua, sehingga akan menghasilkan dampak yang positif, progresif, kreatif dan produktif, kemudian pada akhirnya akan dapat meng-optomal-kan ekonomi syariah untuk menciptakan goodgovernance, post goodgovernance secara berkelanjutan, tentunya dengan bantuan peran media kontemporer yang kian update. Ekonomi syariah juga merupakan pilar dan nilai dasar, dari sikap keyakinan dan sikap rasionalitas untuk sanggup menciptakan terwujudnya pemberdayaan dan kesejahteraan sekaligus pengentasan kemiskinan dalam masyarakat di Indonesia.

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