Protected area targets post-2020 Visconti, Piero; Butchart, Stuart H M; Brooks, Thomas M ...
Science (American Association for the Advancement of Science),
2019-Apr-19, 2019-04-19, 20190419, Letnik:
364, Številka:
6437
Journal Article
Recenzirano
Odprti dostop
Outcome-based targets are needed to achieve biodiversity goals
In 2010, Parties to the Convention on Biological Diversity (CBD) adopted the Strategic Plan for Biodiversity 2011–2020, and its 20 Aichi ...Biodiversity Targets, to catalyze national and international conservation efforts and reverse negative biodiversity trends. With the plan nearing an end, and attention turning toward a post-2020 biodiversity framework, it is timely to assess the strengths, weaknesses, and effectiveness of the Aichi Targets. Aichi Target 11, concerned with establishing effective and representative networks of protected areas (PAs) by 2020, has attracted considerable interest owing to widespread recognition of the pivotal role that appropriately situated and well-managed PAs have in conserving biodiversity (
1
). Substantial advances have been made toward the areal components of Aichi Target 11, with the PA estate increasing by 2.3% on land and 5.4% in the oceans since 2010 and now covering 15% of land and inland freshwater globally and 7% of the oceans (
2
). However, species' population abundance within and outside PAs continues to decline (
1
), the placement and resourcing of the majority of PAs has been poor (
1
,
3
,
4
), and more than half of PAs established before 1992 have suffered increasing human pressure (
5
). We discuss four problems with Aichi Target 11 that have contributed to its limited achievement and propose a formulation for a target for site-based conservation beyond 2020 aimed at overcoming them.
Abstract
We describe the Dark Energy Survey (DES) photometric data set assembled from the first three years of science operations to support DES Year 3 cosmologic analyses, and provide usage notes ...aimed at the broad astrophysics community.
Y3
GOLD
improves on previous releases from DES,
Y1
GOLD
, and Data Release 1 (DES DR1), presenting an expanded and curated data set that incorporates algorithmic developments in image detrending and processing, photometric calibration, and object classification.
Y3
GOLD
comprises nearly 5000 deg
2
of
grizY
imaging in the south Galactic cap, including nearly 390 million objects, with depth reaching a signal-to-noise ratio ∼10 for extended objects up to
i
AB
∼ 23.0, and top-of-the-atmosphere photometric uniformity <3 mmag. Compared to DR1, photometric residuals with respect to Gaia are reduced by 50%, and per-object chromatic corrections are introduced.
Y3
GOLD
augments DES DR1 with simultaneous fits to multi-epoch photometry for more robust galactic color measurements and corresponding photometric redshift estimates.
Y3
GOLD
features improved morphological star–galaxy classification with efficiency >98% and purity >99% for galaxies with 19 <
i
AB
< 22.5. Additionally, it includes per-object quality information, and accompanying maps of the footprint coverage, masked regions, imaging depth, survey conditions, and astrophysical foregrounds that are used to select the cosmologic analysis samples.
In this work, we present the first cosmology results from large-scale structure using the full 5000 deg2 of imaging data from the Dark Energy Survey (DES) Data Release 1. We perform an analysis of ...large-scale structure combining three two-point correlation functions ( 3×2pt ): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) the cross-correlation of source galaxy shear with lens galaxy positions, galaxy–galaxy lensing. To achieve the cosmological precision enabled by these measurements has required updates to nearly every part of the analysis from DES Year 1, including the use of two independent galaxy clustering samples, modeling advances, and several novel improvements in the calibration of gravitational shear and photometric redshift inference. The analysis was performed under strict conditions to mitigate confirmation or observer bias; we describe specific changes made to the lens galaxy sample following unblinding of the results and tests of the robustness of our results to this decision. We model the data within the flat Λ CDM and wCDM cosmological models, marginalizing over 25 nuisance parameters. We find consistent cosmological results between the three two-point correlation functions; their combination yields clustering amplitude S8=0.776-0.017+0.017 and matter density Ω m =0.339-0.031+0.032 in Λ CDM , mean with 68% confidence limits; S8=0.775-0.024+0.026 , Ω m =0.352-0.041+0.035 , and dark energy equation-of-state parameter w=-0.98-0.20+0.32 in wCDM . These constraints correspond to an improvement in signal-to-noise of the DES Year 3 3×2pt data relative to DES Year 1 by a factor of 2.1, about 20% more than expected from the increase in observing area alone. This combination of DES data is consistent with the prediction of the model favored by the Planck 2018 cosmic microwave background (CMB) primary anisotropy data, which is quantified with a probability-to-exceed p=0.13 –0.48. We find better agreement between DES 3×2pt and Planck than in DES Y1, despite the significantly improved precision of both. When combining DES 3×2pt data with available baryon acoustic oscillation, redshift-space distortion, and type Ia supernovae data, we find p=0.34 . Combining all of these datasets with Planck CMB lensing yields joint parameter constraints of S8=0.812-0.008+0.008 , Ω m =0.306-0.005+0.004 , h=0.680-0.003+0.004 , and Σmν<0.13 eV (95% C.L.) in Λ CDM ; S8=0.812-0.008+0.008 , Ω m =0.302-0.006+0.006 , h=0.687-0.007+0.006 , and w=-1.031-0.027+0.030 in wCDM .
ABSTRACT
Determining the distribution of redshifts of galaxies observed by wide-field photometric experiments like the Dark Energy Survey (DES) is an essential component to mapping the matter density ...field with gravitational lensing. In this work we describe the methods used to assign individual weak lensing source galaxies from the DES Year 3 Weak Lensing Source Catalogue to four tomographic bins and to estimate the redshift distributions in these bins. As the first application of these methods to data, we validate that the assumptions made apply to the DES Y3 weak lensing source galaxies and develop a full treatment of systematic uncertainties. Our method consists of combining information from three independent likelihood functions: self-organizing map p(z) (sompz), a method for constraining redshifts from galaxy photometry; clustering redshifts (WZ), constraints on redshifts from cross-correlations of galaxy density functions; and shear ratios (SRs), which provide constraints on redshifts from the ratios of the galaxy-shear correlation functions at small scales. Finally, we describe how these independent probes are combined to yield an ensemble of redshift distributions encapsulating our full uncertainty. We calibrate redshifts with combined effective uncertainties of σ〈z〉 ∼ 0.01 on the mean redshift in each tomographic bin.
We report the results from a search for z > 6.5 quasars using the Dark Energy Survey (DES) Year 3 data set combined with the VISTA Hemisphere Survey (VHS) and WISE All-Sky Survey. Our photometric ...selection method is shown to be highly efficient in identifying clean samples of high-redshift quasars, leading to spectroscopic confirmation of three new quasars – VDES J0244-5008 (z = 6.724), VDES J0020-3653 (z = 6.834), and VDES J0246-5219 (z = 6.90) – which were selected as the highest priority candidates in the survey data without any need for additional follow-up observations. Here, we have obtained spectroscopic observations in the near-infrared for VDES J0244-5008 and VDES J0020-3653 as well as our previously identified quasar, VDES J0224-4711 at z = 6.50 from Reed et al. We use the near-infrared spectra to derive virial black hole masses from the full width at half-maximum of the Mg ii line. These black hole masses are ≃1–2 × 109 M⊙. Combined with the bolometric luminosities of these quasars of Lbol ≃ 1–3 × 1047, these imply that the Eddington ratios are high, ≃0.6–1.1. We consider the C iv emission line properties of the sample and demonstrate that our high-redshift quasars do not have unusual C iv line properties when compared to carefully matched low-redshift samples. Our new DES + VHS z > 6.5 quasars now add to the growing census of luminous, rapidly accreting supermassive black holes seen well into the epoch of reionization.
The reduction of systematic errors is a continuing challenge for model development. Feedbacks and compensating errors in climate models often make finding the source of a systematic error difficult. ...In this paper, it is shown how model development can benefit from the use of the same model across a range of temporal and spatial scales. Two particular systematic errors are examined: tropical circulation and precipitation distribution, and summer land surface temperature and moisture biases over Northern Hemisphere continental regions. Each of these errors affects the model performance on time scales ranging from a few days to several decades. In both cases, the characteristics of the long-time-scale errors are found to develop during the first few days of simulation, before any large-scale feedbacks have taken place. The ability to compare the model diagnostics from the first few days of a forecast, initialized from a realistic atmospheric state, directly with observations has allowed physical deficiencies in the physical parameterizations to be identified that, when corrected, lead to improvements across the full range of time scales. This study highlights the benefits of a seamless prediction system across a wide range of time scales.
Recognizing that protected areas (PAs) are essential for effective biodiversity conservation action, the Convention on Biological Diversity established ambitious PA targets as part of the 2020 ...Strategic Plan for Biodiversity. Under the strategic goal to "improve the status of biodiversity by safeguarding ecosystems, species, and genetic diversity," Target 11 aims to put 17% of terrestrial and 10% of marine regions under PA status by 2020. Additionally and crucially, these areas are required to be of particular importance for biodiversity and ecosystem services, effectively and equitably managed, ecologically representative, and well-connected and to include "other effective area-based conservation measures" (OECMs). Whereas the area-based targets are explicit and measurable, the lack of guidance for what constitutes important and representative; effective; and OECMs is affecting how nations are implementing the target. There is a real risk that Target 11 may be achieved in terms of area while failing the overall strategic goal for which it is established because the areas are poorly located, inadequately managed, or based on unjustifiable inclusion of OECMs. We argue that the conservation science community can help establish ecologically sensible PA targets to help prioritize important biodiversity areas and achieve ecological representation; identify clear, comparable performance metrics of ecological effectiveness so progress toward these targets can be assessed; and identify metrics and report on the contribution OECMs make toward the target. By providing ecologically sensible targets and new performance metrics for measuring the effectiveness of both PAs and OECMs, the science community can actively ensure that the achievement of the required area in Target 11 is not simply an end in itself but generates genuine benefits for biodiversity. En reconocimiento de que las areas protegidas (APs) son esenciales para la acción efectiva de la conservación de la biodiversidad, la Convención Biológica sobre la Diversidad estableció objetivos ambiciosos de áreas protegidas como parte del Plan Estratégico para la Biodiversidad 2020. Bajo la meta estratégica de "mejorar el estado de la biodiversidad por medio de salvaguardar a los ecosistemas, las especies y la diversidad genética", el Objetivo 11 busca poner 17% de las regiones terrestres y 10% de las marinas en estado de AP para 2020. Además y de manera crucial, estas áreas necesitan ser de particular importancia para la biodiversidad y los servicios ambientales, estar manejadas efectiva y equitativamente, ser representativas ecológicamente, estar bien conectadas e incluir "otras medidas de conservación efectiva basadas en el área" (OMCE). Mientras que los objetivos basados en el área son explícitos y medibles, la falta de dirección para qué significan importante, representativo, efectivo y OMCE está afectando cómo las naciones están implementando el objetivo. Existe un riesgo real de que el Objetivo 11 se alcance en términos de área y falle en el objetivo estratégico general por el cual fue establecido ya que las áreas se encuentran mal ubicadas, manejadas inadecuadamente o basadas en una inclusión injustificada de las OMCE. Argumentamos que la comunidad de científicos de la conservación puede ayudar a establecer objetivos de APs ecológicamente sensibles para ayudar a priorizar áreas de biodiversidad importantes y alcanzar la representación ecológica; identificar medidas claras y comparables de la efectividad ecológica para poder evaluar el progreso hacia estos objetivos; e identificar medidas y reportar sobre la contribución que las OMCE aportan al objetivo. Si proporcionamos objetivos ecológicamente sensibles y nuevas medidas de desempeño para calcular la efectividad de las APs y las OMCE, la comunidad científica puede asegurar activamente que la obtención del área exigida en el Objetivo 11 no sea sólo un fin por sí misma, sino también que genere beneficios genuinos para la biodiversidad.
This work and its companion paper, Amon et al. Phys. Rev. D 105, 023514 (2022), present cosmic shear measurements and cosmological constraints from over 100 million source galaxies in the Dark Energy ...Survey (DES) Year 3 data. We constrain the lensing amplitude parameter S8≡σ8 Ω m / 0.3 at the 3% level in Λ CDM : S8=0.759-0.023+0.025 (68% CL). Our constraint is at the 2% level when using angular scale cuts that are optimized for the Λ CDM analysis: S8=0.772-0.017+0.018 (68% CL). With cosmic shear alone, we find no statistically significant constraint on the dark energy equation-of-state parameter at our present statistical power. We carry out our analysis blind, and compare our measurement with constraints from two other contemporary weak lensing experiments: the Kilo-Degree Survey (KiDS) and Hyper-Suprime Camera Subaru Strategic Program (HSC). We additionally quantify the agreement between our data and external constraints from the Cosmic Microwave Background (CMB). Our DES Y3 result under the assumption of Λ CDM is found to be in statistical agreement with Planck 2018, although favors a lower S8 than the CMB-inferred value by 2.3σ (a p -value of 0.02). This paper explores the robustness of these cosmic shear results to modeling of intrinsic alignments, the matter power spectrum and baryonic physics. We additionally explore the statistical preference of our data for intrinsic alignment models of different complexity. The fiducial cosmic shear model is tested using synthetic data, and we report no biases greater than 0.3σ in the plane of S8× Ω m caused by uncertainties in the theoretical models.
We constrain cosmological parameters and galaxy-bias parameters using the combination of galaxy clustering and galaxy-galaxy lensing measurements from the Dark Energy Survey (DES) year-3 data. We ...describe our modeling framework and choice of scales analyzed, validating their robustness to theoretical uncertainties in small-scale clustering by analyzing simulated data. Using a linear galaxy-bias model and redMaGiC galaxy sample, we obtain 10% constraints on the matter density of the Universe. We also implement a nonlinear galaxy-bias model to probe smaller scales that includes parametrization based on hybrid perturbation theory and find that it leads to a 17% gain in cosmological constraining power. We perform robustness tests of our methodology pipeline and demonstrate stability of the constraints to changes in the theory model. Using the redMaGiC galaxy sample as foreground lens galaxies and adopting the best-fitting cosmological parameters from DES year-1 data, we find the galaxy clustering and galaxy-galaxy lensing measurements to exhibit significant signals akin to decorrelation between galaxies and mass on large scales, which is not expected in any current models. This likely systematic measurement error biases our constraints on galaxy bias and the S8 parameter. We find that a scale-, redshift- and sky-area-independent phenomenological decorrelation parameter can effectively capture this inconsistency between the galaxy clustering and galaxy-galaxy lensing. We trace the source of this correlation to a color-dependent photometric issue and minimize its impact on our result by changing the selection criteria of redMaGiC galaxies. Using this new sample, our constraints on the S8 parameter are consistent with previous studies and we find a small shift in the Ωm constraints compared to the fiducial redMaGiC sample. We infer the constraints on the mean host-halo mass of the redMaGiC galaxies in this new sample from the large-scale bias constraints, finding the galaxies occupy halos of mass approximately 1.6×1013 M⊙/h.
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