| 1. |
- Allard, Anna, et al.
(författare)
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Demands on monitoring
- 2023
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Ingår i: Monitoring Biodiversity : Combining Environmental and Social Data. - London : Routledge. - 9781032015934 ; , s. 34-58
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Bokkapitel (refereegranskat)abstract
- This chapter provides a short overview of the types of processes for reporting as well as legislation that governs why and how monitoring is undertaken and some of the ways in which stakeholders are involved at different levels. Because monitoring for the policy side is, by default, mandated monitoring, this type becomes the focus of this chapter, while noting that many policies and legislation may have been prompted by the results of question-driven monitoring, pointing out areas of concern. In fact, the iterative process of monitoring, analysis, and reporting to a government that, in turn, changes the policies to better fit concerns or issues needing addressing can be seen as a co-development.Whereas the previous chapter illustrated what monitoring is, this chapter illustrates some of the demands on monitoring in legislation and policy, where they outline what monitoring is asked to contribute. The chapter reviews legislation on the global scene, on the community level of the European Union, and at national levels in the areas of water bodies and semi-aquatic, agricultural, urban, and forested semi-natural or natural landscapes.
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| 2. |
- Ekström, Magnus, 1966-, et al.
(författare)
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Estimating density from presence/absence data in clustered populations
- 2020
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Ingår i: Methods in Ecology and Evolution. - : John Wiley & Sons. - 2041-210X. ; 11:3, s. 390-402
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Tidskriftsartikel (refereegranskat)abstract
- Inventories of plant populations are fundamental in ecological research and monitoring, but such surveys are often prone to field assessment errors. Presence/absence (P/A) sampling may have advantages over plant cover assessments for reducing such errors. However, the linking between P/A data and plant density depends on model assumptions for plant spatial distributions. Previous studies have shown, for example, how that plant density can be estimated under Poisson model assumptions on the plant locations. In this study, new methods are developed and evaluated for linking P/A data with plant density assuming that plants occur in clustered spatial patterns. New theory was derived for estimating plant density under Neyman-Scott-type cluster models such as the Matern and Thomas cluster processes. Suggested estimators, corresponding confidence intervals and a proposed goodness-of-fit test were evaluated in a Monte Carlo simulation study assuming a Matern cluster process. Furthermore, the estimators were applied to plant data from environmental monitoring in Sweden to demonstrate their empirical application. The simulation study showed that our methods work well for large enough sample sizes. The judgment of what is' large enough' is often difficult, but simulations indicate that a sample size is large enough when the sampling distributions of the parameter estimators are symmetric or mildly skewed. Bootstrap may be used to check whether this is true. The empirical results suggest that the derived methodology may be useful for estimating density of plants such as Leucanthemum vulgare and Scorzonera humilis. By developing estimators of plant density from P/A data under realistic model assumptions about plants' spatial distributions, P/A sampling will become a more useful tool for inventories of plant populations. Our new theory is an important step in this direction.
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| 3. |
- Ekström, Magnus, 1966-, et al.
(författare)
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Estimating density from presence/absence data in clustered populations
- 2021
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 1. Inventories of plant populations are fundamental in ecological research and monitoring, butsuch surveys are often prone to field assessment errors. Presence/ absence (P/A) samplingmay have advantages over plant cover assessments for reducing such errors. However, thelinking between P/A data and plant density depends on model assumptions for plant spatialdistributions. Previous studies have shown, for example, how that plant density can beestimated under Poisson model assumptions on the plant locations. In this study, newmethods are developed and evaluated for linking P/A data with plant density assuming thatplants occur in clustered spatial patterns.2. New theory was derived for estimating plant density under Neyman–Scott-type cluster models such as the Matérn and Thomas cluster processes. Suggested estimators, correspondingconfidence intervals and a proposed goodness-of-fit test were evaluated in a Monte Carlosimulation study assuming a Matérn cluster process. Furthermore, the estimators were applied to plant data from environmental monitoring in Sweden to demonstrate their empiricalapplication.3. The simulation study showed that our methods work well for large enough sample sizes.The judgment of what is ’large enough’ is often difficult, but simulations indicate that asample size is large enough when the sampling distributions of the parameter estimators aresymmetric or mildly skewed. Bootstrap may be used to check whether this is true. Theempirical results suggest that the derived methodology may be useful for estimating densityof plants such as Leucanthemum vulgare and Scorzonera humilis.4. By developing estimators of plant density from P/A data under realistic model assumptions about plants’ spatial distributions, P/A sampling will become a more useful tool forinventories of plant populations. Our new theory is an important step in this direction.
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| 4. |
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| 5. |
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| 6. |
- Ekström, Magnus, 1966-, et al.
(författare)
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Model-based estimation and mapping of plant density based on remotesensing and presence/absence data
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Inventories of populations are of great importance in ecological research. For monitoring plants,presence/absence (P/A) sampling is simple to conduct, since only presence or absence of aspecies on a plot needs to be registered. Estimates of plant density may be obtained from P/Adata but need to be based on model assumptions about the spatial distribution of plants. Wehave showed, in a model-based setting, how to use P/A and remote sensing data for estimatingand mapping plant density for regions and subregions, where the model assumes plant locationsto follow an inhomogeneous Poisson point process. To guard against model misspecifications,we derived a test for assessing the plausibility of the model assumptions of the inhomogeneousPoisson point process. Using empirical data from the Swedish National Forest Inventory as wellas artificial plant population data, we evaluated the performance of the suggested estimators ofplant density and the proposed test of model assumptions, respectively.
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| 7. |
- Esseen, Per-Anders, et al.
(författare)
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Multiple drivers of large-scale lichen decline in boreal forest canopies
- 2022
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 28:10, s. 3293-3309
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Tidskriftsartikel (refereegranskat)abstract
- Thin, hair-like lichens (Alectoria, Bryoria, Usnea) form conspicuous epiphyte communities across the boreal biome. These poikilohydric organisms provide important ecosystem functions and are useful indicators of global change. We analyse how environmental drivers influence changes in occurrence and length of these lichens on Norway spruce (Picea abies) over 10 years in managed forests in Sweden using data from >6000 trees. Alectoria and Usnea showed strong declines in southern-central regions, whereas Bryoria declined in northern regions. Overall, relative loss rates across the country ranged from 1.7% per year in Alectoria to 0.5% in Bryoria. These losses contrasted with increased length of Bryoria and Usnea in some regions. Occurrence trajectories (extinction, colonization, presence, absence) on remeasured trees correlated best with temperature, rain, nitrogen deposition, and stand age in multinomial logistic regression models. Our analysis strongly suggests that industrial forestry, in combination with nitrogen, is the main driver of lichen declines. Logging of forests with long continuity of tree cover, short rotation cycles, substrate limitation and low light in dense forests are harmful for lichens. Nitrogen deposition has decreased but is apparently still sufficiently high to prevent recovery. Warming correlated with occurrence trajectories of Alectoria and Bryoria, likely by altering hydration regimes and increasing respiration during autumn/winter. The large-scale lichen decline on an important host has cascading effects on biodiversity and function of boreal forest canopies. Forest management must apply a broad spectrum of methods, including uneven-aged continuous cover forestry and retention of large patches, to secure the ecosystem functions of these important canopy components under future climates. Our findings highlight interactions among drivers of lichen decline (forestry, nitrogen, climate), functional traits (dispersal, lichen colour, sensitivity to nitrogen, water storage), and population processes (extinction/colonization).
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| 8. |
- Gerdtsson, Axel, et al.
(författare)
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Surgical Complications in Postchemotherapy Retroperitoneal Lymph Node Dissection for Nonseminoma Germ Cell Tumour : A Population-based Study from the Swedish Norwegian Testicular Cancer Group
- 2020
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Ingår i: European Urology Oncology. - : Elsevier BV. - 2588-9311. ; 3:3, s. 382-389
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Reports on perioperative complications after postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) for nonseminoma germ cell tumour (NSGCT) are from experienced single centres, with a lack of population-based studies. OBJECTIVE: To assess the complications of bilateral and unilateral PC-RPLND. DESIGN, SETTING, AND PARTICIPANTS: A prospective, population-based, observational multicentre study included all patients with NSGCT who underwent PC-RPLND in Norway and Sweden during 2007-2014. Of a total of 318 patients, 87 underwent bilateral PC-RPLND and 231 underwent unilateral PC-RPLND. The median follow-up was 6 yr. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Bilateral and unilateral PC-RPLND were compared for the outcomes of intra- and postoperative complications (graded by Clavien-Dindo) and retrograde ejaculation (with or without nerve-sparing surgery). Complications were reported as absolute counts and percentages. The χ2 test was used for comparisons. RESULTS AND LIMITATIONS: The incidence of intraoperative complications was higher for bilateral PC-RPLND than for unilateral PC-RPLND (14% vs 4.3%, p = 0.003), with ureteral injury as the most frequent reported complication (2% of the patients). Postoperative complications were more common after bilateral than after unilateral PC-RPLND (45% vs 25%, p = 0.001) with Clavien ≥3b reported in 8.3% and 2.2%, respectively (p = 0.009). Lymphatic leakage was the most common complication occurring in 11% of the patients. Retrograde ejaculation occurred more frequently after bilateral than after unilateral surgery (59% vs 32%, p < 0.001). Limitations of the study include reporting of retrograde ejaculation, which was based on a chart review. CONCLUSIONS: Intra- and postoperative complications including retrograde ejaculation are more frequent after bilateral PC-RPLND than after unilateral PC-RPLND. PATIENT SUMMARY: Lymph node dissection in patients with testicular cancer puts them at risk of complications. In this study, we present the complications after lymph node dissection.
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| 9. |
- Gerdtsson, Axel, et al.
(författare)
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Unilateral or Bilateral Retroperitoneal Lymph Node Dissection in Nonseminoma Patients with Postchemotherapy Residual Tumour? Results from RETROP, a Population-based Mapping Study by the Swedish Norwegian Testicular Cancer Group
- 2022
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Ingår i: European Urology Oncology. - : Elsevier BV. - 2588-9311. ; 5:2, s. 235-243
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The distribution of retroperitoneal lymph node metastases for patients with nonseminoma and a residual tumour of 10-49 mm in a population-based setting is unknown. This information is needed to justify selection of patients for a unilateral template resection. OBJECTIVE: To describe the location of retroperitoneal metastases and recurrences in patients with nonseminoma germ cell tumour (NSGCT) with a residual tumour of 10-49 mm. DESIGN, SETTING, AND PARTICIPANTS: RETROP is a population-based prospective observational mapping study of 213 patients in Sweden and Norway with a retroperitoneal residual tumour of 10-49 mm who underwent postchemotherapy retroperitoneal lymph node dissection for metastatic NSGCT during 2007-2014 with median follow-up of 100 mo. Patients were classified according to the testis primary tumour and the distribution of unilateral or bilateral lymph node metastases (with reference to the aorta) present on pre- and/or postchemotherapy computed tomography (CT) scans. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The distribution and rate of teratoma or cancer in unilateral or bilateral retroperitoneal fields and the location and rate of retroperitoneal recurrence were measured. RESULTS AND LIMITATIONS: In total, 65% of the patients had unilateral retroperitoneal lymph node metastases (RLNMs) on CT scans. Patients with unilateral RLNMs had a low risk of contralateral teratoma or cancer (1.6% for right- and 2.6% for left-sided NSGCT) or retroperitoneal recurrence (0% for right- and 4% for left-sided NSGCT). A weakness of the study is that the pathology specimen could not be fully designated to one specific area for some of the patients. CONCLUSIONS: Men with postchemotherapy residual disease of 10-49 mm and unilateral metastases on pre- and postchemotherapy CT scans have a low risk of contralateral disease and should be considered for a unilateral template resection. PATIENT SUMMARY: The surgeon can use computed tomography (CT) scans in deciding on the extent of lymph node dissection in patients with testicular cancer.
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| 10. |
- Gozé, Léna, et al.
(författare)
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Estimation of plant density based on presence/absence data using hybrid inference
- 2024
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Ingår i: Ecological Informatics. - : Elsevier. - 1574-9541 .- 1878-0512. ; 80
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Tidskriftsartikel (refereegranskat)abstract
- Monitoring of plant populations has become more and more important, especially in the current context of environmental change. In this paper, we propose methods to estimate plant density from presence/absence surveys, wherein the presence or absence of each species is recorded on sample plots. Presence/absence sampling is a useful and relatively simple method for monitoring state and change of plant communities. Moreover, it has advantages compared to traditional plant cover assessment, the latter being more prone to observer bias. We present a hybrid estimation framework, that combines model- and design-based inference features, in which a generalised linear model (for binary presence/absence data) and an inhomogeneous Poisson model (for plant locations) are used to estimate plant density in a region of interest. We look at two different cases, the first one with a known area and the second one where the area is unknown and must be estimated. Our methods are applied to real data on Vaccinium vitis-idaea from the Swedish National Forest Inventory as well as simulated data to assess the performance of our estimators of plant density and corresponding variance estimators. The results obtained are promising and indicate that this method has a potential to add considerable analytic strength to monitoring programmes that collect presence/absence data.
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