How strong is the evidence – Based on macroinvertebrate community responses – That river restoration works?

We reviewed river rehabilitation studies published from 1984 to 2019 to identify factors that might limit effective rehabilitation. This encompasses 89 papers that reported outcomes of 379 independent projects. We found that methods used to evaluate the outcomes of rehabilitation projects may have failed to properly assess the outcomes, which has led to a poor diagnosis of both the “problem” and the effectiveness of any “solution”. We identified four methodological limitations that have often precluded the rigorous assessment of the effectiveness of stream rehabilitation:(1)The most comprehensive Before–After–Control–Impact (BACI) study design was not common practice.(2)Most studies sampled rivers for only one season following rehabilitation, and therefore could not account for seasonal or annual variations that could affect macroinvertebrate community composition.(3)Multi-habitat sampling – to comprehensively represent macroinvertebrate communities in study reaches – was rarely applied.(4)The most commonly employed indicators of rehabilitation success were macroinvertebrate taxa richness and diversity, even though these measures may fail to identify other consequential changes in ecosystem structure and function. Ecosystem functional indicators such as macroinvertebrate Functional Feeding Group (FFG) and Ephemeroptera–Plecoptera–Trichoptera (EPT) diversity, density, biomass and secondary production often had better responses, but were rarely assessed.Future rehabilitation projects and monitoring of their outcomes should aim to rehabilitate ecosystem functions, not solely structures. BACI monitoring design and multi-habitat sampling at in-stream biotope level are required to detect physical and biological changes that may otherwise go unnoticed. The presence of upstream population sources can facilitate biotic recolonisation and decrease the post-project time frame of recovery.</div

Impact of phosphorus control measures on in-river phosphorus retention associated with point source pollution

In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2-4 years). In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990-2001), were used to model daily phosphorus fluxes and monthly in-river phosphorus retention in the lowland calcareous River Wensum, Norfolk, UK. The calibrated model explained 79% and 89% of the observed variance before and after phosphorus control, respectively. A split test revealed that predicted TP loads were in good agreement with observed TP loads (r[superscript 2]=0.85), although TP loads were underestimated under high flow conditions. During relatively dry years, there was no net export of phosphorus from the catchment. High retention of phosphorus occurred, particularly during the summer months, which was not compensated for, by subsequent higher flow events. This was despite a relatively modest critical discharge (Q) above which net remobilisation occur. Phosphorus removal from the effluent at two major STWs (Sewage Treatment Works) reduced phosphorus retention but not the remobilisation. This may indicate that the presence of impoundments and weirs, or overbank flows may have more control on the phosphorus dynamics under high flow conditions. Further phosphorus remedial strategies will be necessary to prevent downstream risks of eutrophication occurring independently of the unpredictable variability in weather conditions. More research is also needed to quantify the impact of the weir and overbank flows on phosphorus dynamics

Species diversity, community structure, and distribution patterns in western Himalayan alpine pastures of Kashmir, Pakistan

Western Himalayan alpine pastures are among the most diverse ecological locations on the globe. Four alpine pastures were investigated to study species distribution patterns, richness, similarity, and community structure in Bagh District, Azad Kashmir, Pakistan. Four communities, Poa–Primula–Sibbaldia, Primula–Caltha–Primula, Poa alpina–Poa pratensis–Scirpus, and Sibbaldia–Poa–Scirpus, were identified on the basis of an importance value index. The average value of species richness was 1.42; Simpson's and Shannon–Wiener's diversity values were 3.13 and 0.91, respectively; the degree of maturity index was 44.1; and species evenness was 0.901. Local alpine flora was dominated by a hemicriptophytic life form with microphyllous leaf spectra. The species–environment correlation was analyzed using canonical correspondence analysis. A negative correlation of both diversity and richness was revealed with altitudinal gradient. Anthropogenic disturbances showed a significant negative impact on distribution of medicinal and palatable species. Unpalatable species dominated the local flora, indicating the heavy grazing pressure in the area. Development and implementation of regional conservation strategies are recommended to protect the threatened Himalayan alpine biodiversity

Medicinal flora and ethnoecological knowledge in the Naran Valley, Western Himalaya, Pakistan

Background: Mountain ecosystems all over the world support a high biological diversity and provide home and services to some 12% of the global human population, who use their traditional ecological knowledge to utilise local natural resources. The Himalayas are the world's youngest, highest and largest mountain range and support a high plant biodiversity. In this remote mountainous region of the Himalaya, people depend upon local plant resources to supply a range of goods and services, including grazing for livestock and medicinal supplies for themselves. Due to their remote location, harsh climate, rough terrain and topography, many areas within this region still remain poorly known for its floristic diversity, plant species distribution and vegetation ecosystem service. Methods: The Naran valley in the north-western Pakistan is among such valleys and occupies a distinctive geographical location on the edge of the Western Himalaya range, close to the Hindu Kush range to the west and the Karakorum Mountains to the north. It is also located on climatic and geological divides, which further add to its botanical interest. In the present project 120 informants were interviewed at 12 main localities along the 60 km long valley. This paper focuses on assessment of medicinal plant species valued by local communities using their traditional knowledge. Results: Results revealed that 101 species belonging to 52 families (51.5% of the total plants) were used for 97 prominent therapeutic purposes. The largest number of ailments cured with medicinal plants were associated with the digestive system (32.76% responses) followed by those associated with the respiratory and urinary systems (13.72% and 9.13% respectively). The ailments associated with the blood circulatory and reproductive systems and the skin were 7.37%, 7.04% and 7.03%, respectively. The results also indicate that whole plants were used in 54% of recipes followed by rhizomes (21%), fruits (9.5%) and roots (5.5%). Conclusion: Our findings demonstrate the range of ecosystem services that are provided by the vegetation and assess how utilisation of plants will impact on future resource sustainability. The study not only contributes to an improved understanding of traditional ethno-ecological knowledge amongst the peoples of the Western Himalaya but also identifies priorities at species and habitat level for local and regional plant conservation strategies