scholarly journals Impact of local- and regional-scale restoration measures on a vulnerable rich fen in the Naardermeer nature reserve (the Netherlands)

Plant Ecology ◽  
2020 ◽  
Vol 221 (10) ◽  
pp. 893-911
Author(s):  
Annegreet Veeken ◽  
Martin J. Wassen
Keyword(s):  
The Netherlands ◽  
Nature Reserve ◽  
Regional Scale ◽  
N Deposition ◽  
Vegetation Composition ◽  
Atmospheric N Deposition ◽  
Rich Fen ◽  
Poor Fen ◽  
Before And After ◽  
Restoration Measures

Abstract Restoration of rich fens is commonly attempted through local-scale measures, such as removal of sod or blockage of ditches. However, regional-scale restoration measures, that aim to re-establish the original hydrology in which rich fens developed, might have a more long-lasting effect. We investigated the effect of local- and regional-scale restoration measures on a vulnerable rich fen in the Naardermeer nature reserve in the Netherlands. We compared water quality and vegetation composition of the fen before and after the restoration measures, almost 30 years apart. Overall rich fen species increased and although this indicates the desired increased supply of fresh mineral-rich groundwater to the fen, continued succession towards poor fen vegetation has not been prevented in the entire fen. Despite sod layer removal, we observed an increase in a Polytrichum-dominated vegetation in patches that are primarily fed by rainwater. Our findings confirm results from a previous study which showed that brackish palaeo-groundwater is still contributing substantially to the water balance of the fen, especially in periods of precipitation deficit. We conclude that the local- and regional-scale restoration measures have been successful in increasing the abundance of rich fen species in parts of the fen. However, considering the pressures of climate change and high atmospheric N-deposition on the fen, it is uncertain whether rich fen species can be sustained in quite nutrient-poor conditions in the future. Therefore, there is a need for continued management that keeps the nutrient-poor and mineral-rich conditions of the fen intact.

Indirect N2O emission due to atmospheric N deposition for the Netherlands

2005 ◽  
Vol 39 (32) ◽  
pp. 5827-5838 ◽  
Author(s):  
Hugo Denier van der Gon ◽  
Albert Bleeker
Keyword(s):  
The Netherlands ◽  
N2o Emission ◽  
N Deposition ◽  
Atmospheric N Deposition

Groundwater chemistry and vegetation of gradients from rich fen to poor fen in the Naardermeer (the Netherlands)

Vegetatio ◽  
1988 ◽  
Vol 79 (3) ◽  
pp. 117-132 ◽  
Author(s):  
M. J. Wassen ◽  
A. Barendregt ◽  
M. C. Bootsma ◽  
P. P. Schot
Keyword(s):  
The Netherlands ◽  
Groundwater Chemistry ◽  
Rich Fen ◽  
Poor Fen

Restoration of the broads-area Alde Feanen, The Netherlands: measures and results

1995 ◽  
Vol 31 (8) ◽  
pp. 229-233 ◽  
Author(s):  
T. H. L. Claassen ◽  
R. Maasdam
Keyword(s):  
Water Quality ◽  
The Netherlands ◽  
Nature Reserve ◽  
Monitoring Program ◽  
Middle Part ◽  
Main Target ◽  
First Results ◽  
Basin Water ◽  
Restoration Measures

The Alde Feanen (2500 ha) is a relatively large nature reserve in the lower middle part of the province of Friesland, The Netherlands. The area consists of grass- and woodland, peat-diggings, and broads and open basin water. The nature-function -with specific ecological goals- is the main target for the water management. However, the water quality in the various waters did not agree with the formulated standards for this area. In the period 1990–1993 many restoration measures have been realised, namely isolation from the basin water, dredging, biomanipulation, and hydrological re-arrangement. A monitoring program, started at the end of 1987, follows the effects of the various measures. First results are an improvement of the water quality of hydrological isolation, and of dredging. Biomanipulation gives varying results, depending on the effectivity of the removal of bream. Local factors, such as a colony of cormorants, can nullify restoration measures. In general, water quality is improving, which gives a perspective on the re-introduction of the otter.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

ATMOSPHERIC N DEPOSITION TO THE COASTAL AREA OF THE BLACK SEA: SOURCES, INTRA-ANNUAL VARIATIONS AND IMPORTANCE FOR BIOGEOCHEMISTRY AND PRODUCTIVITY OF THE SURFACE LAYER

2017 ◽  
Author(s):  
Alla Varenik ◽  
Alla Varenik ◽  
Sergey Konovalov ◽  
Sergey Konovalov
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Marine Ecosystem ◽  
C:N Ratio ◽  
N Deposition ◽  
Local Source ◽  
The Black Sea ◽  
Coastal Zones ◽  
Atmospheric N Deposition ◽  
Urban Location

Atmospheric precipitations can be an important source of nutrients to open and coastal zones of marine ecosystem. Jickells [1] has published that atmospheric depositions can sup-port 5-25% of nitrogen required to primary production. Bulk atmospheric precipitations have been collected in a rural location at the Black Sea Crimean coast – Katsiveli settlement, and an urban location – Sevastopol city. Samples have been analyzed for inorganic fixed nitrogen (IFN) – nitrate, nitrite, and ammonium. Deposi-tions have been calculated at various space and time scales. The monthly volume weighted mean concentration of IFN increases from summer to winter in both locations. A significant local source of IFN has been revealed for the urban location and this source and its spatial influence have been quantified. IFN deposition with atmospheric precipitations is up to 5% of its background content in the upper 10 m layer of water at the north-western shelf of the Black Sea. Considering Redfield C:N ratio (106:16) and the rate of primary production (PP) in coastal areas of the Black Sea of about 100-130 g C m-2 year-1 we have assessed that average atmospheric IFN depositions may intensify primary production by 4.5% for rural locations, but this value is increased many-fold in urban locations due to local IFN sources.

Management of the Dutch Waddensea

1984 ◽  
Vol 16 (3-4) ◽  
pp. 485-495 ◽  
Author(s):  
D Vreugdenhil
Keyword(s):  
The Netherlands ◽  
Middle Ages ◽  
Human Activities ◽  
Nature Reserve ◽  
The Other ◽  
Hydrological Processes ◽  
Dutch Government ◽  
Shallow Sea ◽  
Management Objectives ◽  
Late Middle Ages

It was not until the late Middle Ages that the sea penetrated far into the interior of The Netherlands, thus flooding three quarters of a million hectares of land. Since then half a million hectares have been reclaimed from the sea. The Dutch Government chose to preserve the remaining quarter of a million hectares of shallow sea with mudflats of the Waddensea as a nature reserve. The management objectives are at one hand to preserve all characteristic habitats and species with a minimal interference by human activities in geomorphological and hydrological processes, and at the other hand to guarantee the safety against the sea of the inhabitants of the adjacent mainland and islands and to facilitate certain economic and recreational uses of the Waddensea without jeopardizing the natural qualities. These objectives are being elaborated in managementplans.

scholarly journals Changes in Online Psychoactive Substance Trade via Telegram during the COVID-19 Pandemic

2021 ◽  
pp. 1-6
Author(s):  
Matthijs Blankers ◽  
Daan van der Gouwe ◽  
Lavinia Stegemann ◽  
Laura Smit-Rigter
Keyword(s):  
Social Media ◽  
The Netherlands ◽  
Relative Increase ◽  
Lysergic Acid ◽  
Lysergic Acid Diethylamide ◽  
Psychoactive Substance ◽  
Before And After ◽  
Other Substances

<b><i>Background:</i></b> In this article, we present an evaluation of online psychoactive substance trade via Telegram, a free encrypted social media messenger service. The evaluation took place during the COVID-19 pandemic, which allowed us to monitor the effects of the spring 2020 lockdown in the Netherlands on substance trade via Telegram. <b><i>Objective:</i></b> The objective of this study was to evaluate whether changes in psychoactive substance trade on Telegram markets in the Netherlands can be observed during the COVID-19 pandemic. <b><i>Results:</i></b> Between December 2, 2019, and June 29, 2020, a total of 70,226 posts appeared in two analyzed Telegram groups. A total of 5,643 posts were psychoactive substance related. Based on the analyzed posts, Telegram is mostly a ‘“sellers” market as only a minority of the posts (6.3%) could be identified as a request for a substance. The proportion of posts related to specific substances varied between the periods before, during, and after the lockdown. The proportion of posts on the stimulants ecstasy, cocaine, and amphetamine was lower during the lockdown than before and after. For psychedelics – ketamine, lysergic acid diethylamide (LSD), and 2,5-dimethoxy-4-bromophenethylamine (2C-B) – and other substances, there was a relative increase in the number of posts during the lockdown, which was maintained after the lockdown. <b><i>Conclusions:</i></b> Telegram analysis shows that in the Netherlands, online psychoactive substance trade may have been affected during the COVID-19 pandemic. The direction of this effect was different for different classes of substances.

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