Ecology and conservation of the rare annual Petrorhagia nanteuilii (Childing Pink) on the vegetated shingle spits of Pagham Harbour, West Sussex

Petrorhagia nanteuilii (Childing Pink), a nationally rare annual, exists at only one location in the UK on the vegetated shingle spits at Pagham Harbour, West Sussex. Primarily found in dry grassland habitats throughout Spain and Portugal, at present its only known threat in the UK is the invasive perennial, Centranthus ruber (Red Valerian); however for conservation of Petrorhagia nanteuilii to be sustainable, its presence at Pagham Harbour must be better understood. The aim of this study was therefore to investigate the local distribution and ecological associations of Petrorhagia nanteuilii in order to understand the relationships between Petrorhagia nanteuilii and the vegetated shingle communities and thereby inform their conservation. Field surveys of the shingle flora were undertaken in 2007 and 2011. Vegetation was sampled and the edaphic and physical environment was also investigated using TWINSPAN, multivariate analyses and GIS. The results of the study show that Petrorhagia nanteuilii has little association with the true vegetated shingle communities on the shingle spits. They also reveal that in recent years the species has spread rapidly across parts of the site due to a number of adaptations aiding its survival and recent shifts in conservation management that have influenced spit morphology. The ecological disconnection that exists between Petrorhagia nanteuilii and the true shingle communities means it is unlikely that management strategies will be conflicting. The study concludes that conservation of both is feasible, however for management to be sustainable, both short-term and long-term strategies must be considered.     

Examining the relationship between local extinction risk and position in range

Over half of globally threatened animal species have experienced rapid geographic range loss. Identifying the parts of species’ distributions most vulnerable to local extinction would benefit conservation planning. However, previous studies give little consensus on whether ranges decline to the core or edge. We built on previous work by using empirical data to examine the position of recent local extinctions within species’ geographic ranges, address range position as a continuum, and explore the influence of environmental factors. We aggregated point‐locality data for 125 Galliform species from across the Palearctic and Indo‐Malaya into equal‐area half‐degree grid cells and used a multispecies dynamic Bayesian occupancy model to estimate rates of local extinctions. Our model provides a novel approach to identify loss of populations from within species ranges. We investigated the relationship between extinction rates and distance from range edge by examining whether patterns were consistent across biogeographic realm and different categories of land use. In the Palearctic, local extinctions occurred closer to the range edge than range core in both unconverted and human‐dominated landscapes. In Indo‐Malaya, no pattern was found for unconverted landscapes, but in human‐dominated landscapes extinctions tended to occur closer to the core than the edge. Our results suggest that local and regional factors override general spatial patterns of recent local extinction within species’ ranges and highlight the difficulty of predicting the parts of a species’ distribution most vulnerable to threat.     

Equity trade‐offs in conservation decision making

Conservation decisions increasingly involve multiple environmental and social objectives, which result in complex decision contexts with high potential for trade‐offs. Improving social equity is one such objective that is often considered an enabler of successful outcomes and a virtuous ideal in itself. Despite its idealized importance in conservation policy, social equity is often highly simplified or ill‐defined and is applied uncritically. What constitutes equitable outcomes and processes is highly normative and subject to ethical deliberation. Different ethical frameworks may lead to different conceptions of equity through alternative perspectives of what is good or right. This can lead to different and potentially conflicting equity objectives in practice. We promote a more transparent, nuanced, and pluralistic conceptualization of equity in conservation decision making that particularly recognizes where multidimensional equity objectives may conflict. To help identify and mitigate ethical conflicts and avoid cases of good intentions producing bad outcomes, we encourage a more analytical incorporation of equity into conservation decision making particularly during mechanistic integration of equity objectives. We recommend that in conservation planning motivations and objectives for equity be made explicit within the problem context, methods used to incorporate equity objectives be applied with respect to stated objectives, and, should objectives dictate, evaluation of equity outcomes and adaptation of strategies be employed during policy implementation.     

Diversity, host affinity, and distribution of seed-infecting fungi: a case study with Cecropia

Recruitment limitation has been proposed as an important mechanism contributing to the maintenance of tropical tree diversity. For pioneer species, infection by fungi significantly reduces seed survival in soil, potentially influencing both recruitment success and adult distributions. We examined fresh seeds of four sympatric Cecropia species for evidence of fungal infection, buried seeds for five months in common gardens below four C. insignis crowns in central Panama, and measured seed survival and fungal infection of inviable seeds. Seed survival varied significantly among species and burial sites, and with regard to local (Panama) vs. foreign (Costa Rica) maternal seed sources. Fresh seeds contained few cultivable fungi, but > 80% of soil-incubated seeds were infected by diverse Ascomycota, including putative pathogens, saprophytes, and endophytes. From 220 isolates sequenced for the nuclear internal transcribed spacer region (ITS), 26 of 73 unique genotypes were encountered more than once. Based on the most common genotypes, fungal communities demonstrate host affinity and are structured at the scale of individual crowns. Similarity among fungal communities beneath a given crown was significantly greater than similarity among isolates found under different crowns. However, the frequency of rare species suggests high fungal diversity and fine-scale spatial heterogeneity. These results reveal complex plant-fungal interactions in soil and provide a first indication of how seed survival in tropical forests may be affected by fungal community composition.     

Timber Certification: Where Is the Voice of the Biologist?

Editor's note: This Conservation Forum begins with a reprinted editorial by Elizabeth Bennett from the August 2000 issue of Conservation Biology . Several papers were submitted in repsonse to that piece, and it is reprinted here to start this forum.     

Evaluation of phenol detoxification by Brassica napus hairy roots, using Allium cepa test

Introduction  

Meristematic mitotic cells of Allium cepa constitute an adequate material for cytotoxicity and genotoxicity evaluation of environmental pollutants, such as phenol, which is a contaminant frequently found in several industrial effluents.     

Economic assessment of rewilding versus agri-environmental nature management

Policies aiming at improving biodiversity often consist of costly agri-environmental schemes, i.e. subsidized grazing or mowing of semi-natural areas. However, these practices have widely been found to be insufficient to mitigate biodiversity loss. Rewilding, i.e. restoring natural processes in self-sustaining biodiverse ecosystems, has been proposed as an alternative and is hypothesized to be a more cost-efficient approach to promote biodiversity conservation. Rewilding requires the availability of large natural areas which are not allocated for farming, forestry, and infrastructure to avoid potential conflicts over the use of the area. We perform an ex-ante private cost–benefit analysis of the establishment of four large nature reserves for rewilding in Denmark. We analyse the economic effects of changing from summer grazing in nature areas in combination with cultivated fields and forestry to the establishment of nature reserves in four case areas. We consider two scenarios involving conversion of agriculture and forestry areas into natural areas in combination with either extensive year-round cattle grazing or rewilding with wild large herbivores. In two case areas, it appears possible to establish large nature areas without incurring extra costs. Additionally, rewilding further reduces costs compared to year-round cattle grazing. Two opposing effects were dominant: increased economic rent occurred from the shift from summer grazing to year-round grazing or rewilding, while cessation of agriculture and forestry caused opportunity costs.     

Effects of ultraviolet radiation on toad early life stages

Background  Exposure to harmful levels of ultraviolet-B radiation (UVB), a component of solar radiation, has been suggested as a potential cause of amphibian declines. Methods  We measured solar radiation (UVB, ultraviolet-A, and visible) wavebands in breeding ponds of Bufo boreas (boreal toad, a montane species that has undergone severe population declines) and Bufo woodhousii (Woodhouse’s toad, a plains toad that has not experienced declines) and examined tolerances of these species to simulated solar UVB exposures in the laboratory. Results  We found larvae of both species to be tolerant of simulated solar UVB in excess of solar UVB levels observed in their breeding ponds. B. boreas tadpoles were more tolerant of simulated solar UVB exposure than B. woodhousii tadpoles, possibly because of greater amounts of photoprotective melanin in B. boreas skin. Conclusions  UVB levels observed in B. boreas habitats do not currently appear to constitute a threat to the survival of these animals; however, long-term (>1 month) exposure to UVB levels comparable to levels associated with the water interface appears to reduce survival in B. woodhousii tadpoles. Therefore, future increases in surface and water column UVB radiation in bufonid habitats might pose significant survival risks to B. boreas or B. woodhousii populations.     

Determination of trace triazine and chloroacetamide herbicides in tile-fed drainage ditch water using solid-phase microextraction coupled with GC-MS

Solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) was used to analyze two triazine (atrazine and simazine) and three chloroacetamide herbicides (acetochlor, alachlor, and metolachlor) in water samples from a midwest US agricultural drainage ditch for two growing seasons. The effects of salt concentration, sample volume, extraction time, and injection time on extraction efficiency using a 100-mum polydimethylsiloxane-coated fiber were investigated. By optimizing these parameters, ditch water detection limits of 0.5 microgL(-1) simazine and 0.25 microgL(-1) atrazine, acetochlor, alachlor, and metolachlor were achieved. The optimum salt concentration was found to be 83% NaCl, while sample volume (10 or 20 mL) negligibly affected analyte peak areas. The optimum extraction time was 40 min, and the optimum injection time was 15 min. Results indicated that atrazine levels in the ditch water exceeded the US maximum contaminant level for drinking water 12% of the time, and atrazine was the most frequently detected among studied analytes.     

Nonylphenol algal bioaccumulation and its effect through the trophic chain

Nonylphenol is a metabolic intermediate from the microbial transformation of detergents used worldwide. While nonylphenol shows some acute toxicity, it is also able to mimic important hormones resulting in the disruption of several processes by interfering with the signals that control the overall physiology of the organism. The effect of the pollutant nonylphenol (NP) through the trophic chain was studied. Microalgae Isochrysis galbana was able to bioconcentrate NP 6940 times, where 77% of initial NP (100microgl(-1)) is accumulated intracellularly after 1-h incubation. Crustacean Artemia fransiscana showed 25% higher growth when fed with NP-rich algae. However, Artemia metabolized almost all NP ingested and only traces of NP could be found in the organism, eliminating future NP effects. Zebrafish (Brachydanio rerio) were affected by the presence of 171microgg(-1) of NP in the diet, showing higher levels of the hormone vitellogenin and lower levels of cytochrome P450 activity. These results showed that organisms placed in the first level of trophic chain are able to significantly bioconcentrate the pollutant and endocrine disruptor NP. These grassed organisms affect the growth of crustacean. Moreover, the organisms placed on the top of some trophic chains, such as fish, could be affected by the presence of NP in their food, in both the hormone levels and metabolic enzymes. This work shows that the environmental presence of NP should be considered as a risk for the organisms living in an ecosystem.