Around the world, there is growing desire and momentum for ecological restoration to happen faster, with better quality, and in more extensive areas. The question we ask is how can laws and ...governmental regulations best contribute to effective, successful, and broad‐scale restoration? In the state of São Paulo, Brazil, there is a legal instrument (SMA 08‐2008) whose aim is to increase the effectiveness of tropical forest restoration projects in particular. It establishes, among other things, requirements regarding the minimum number of native tree species to be reached within a given period of time in restoration projects and the precise proportion of functional groups or threatened species to be included when reforestation with native species is used as a restoration technique. There are, however, two differing perspectives among Brazilian restoration ecologists on the appropriateness of such detailed legal rules. For some, the rules help increase the chances that mandatory projects of ecological restoration will succeed. For the other group, there is no single way to achieve effective ecosystem restoration, and the existing science and know‐how are far from sufficient to establish standardized technical and methodological norms or to justify that such norms be imposed. Both points of view are discussed here, aiming to help those developing new legislation and improving existing laws about ecological restoration. The precedents established in São Paulo, and at the federal level in Brazil, and the ongoing debate about those laws are worth considering and possibly applying elsewhere.
We present measurements of the fractional momentum loss (Sloss = delta pT / pT) of high-transverse-momentum-identified hadrons in heavy-ion collisions. Using pi0 in Au + Au and Cu + Cu collisions at ...√sNN = 62.4 and 200 GeV measured by the PHENIX experiment at the Relativistic Heavy Ion Collider and and charged hadrons in Pb + Pb collisions measured by the ALICE experiment at the Large Hadron Collider, we studied the scaling properties of Sloss as a function of a number of variables: the number of participants, Npart, the number of quark participants, Nqp, the charged-particle density, dNch/dη, and the Bjorken energy density times the equilibration time, epsilonBjτ0. We also find that the pT, where Sloss has its maximum, varies both with centrality and collision energy. Above the maximum, Sloss tends to follow a power-law function with all four scaling variables. Finally, the data at √sNN = 200 GeV and 2.76 TeV, for sufficiently high particle densities, have a common scaling of Sloss with dNch/dη and εBjτ0, lending insight into the physics of parton energy loss.
The versatility of RHIC allowed the PHENIX collaboration to measure low momentum direct photons from small systems, such as p+p, p+A, d+Au at sNN=200GeV as well as from large A+A systems, such as ...Au+Au and Cu+Cu at 200GeV and Au+Au at 62.4GeV and 39GeV. In these measurements PHENIX has discovered a large excess over the scaled p+p yield of direct photons in A+A collisions, and a non-zero excess over the scaled p+p yield in central p+A collisions. Another PHENIX discovery is that at low-pT the integrated yield of direct photons, dNγ/dy, from large systems follows a universal scaling as a function of the charged-particle multiplicity, (dNch/dη)α, with α = 1.25. The observed scaling properties of direct photons from these systems show that the photon production yield increases faster than the charged-particle multiplicity.
High‐diversity reforestation can help jumpstart tropical forest restoration, but obtaining viable seedlings is a major constraint: if nurseries do not offer them, it is hard to plant all the species ...one would like. From 2007 to 2009, we investigated five different seed acquisition strategies employed by a well‐established tree nursery in southeastern Brazil, namely (1) in‐house seed harvesters; (2) hiring a professional harvester; (3) amateur seed harvesters; or (4) a seed production cooperative, as well as (5) participating in a seed exchange program. In addition, we evaluated two strategies not dependent on seeds: harvesting seedlings from native tree species found regenerating under Eucalyptus plantations, and in a native forest remnant. A total of 344 native tree and shrub species were collected as seeds or seedlings, including 2,465 seed lots. Among these, a subset of 120 species was obtained through seed harvesting in each year. Overall, combining several strategies for obtaining planting stocks was an effective way to increase species richness, representation of some functional groups (dispersal syndromes, planting group, and shade tolerance), and genetic diversity of seedlings produced in forest tree nurseries. Such outcomes are greatly desirable to support high‐diversity reforestation as part of tropical forest restoration. In addition, community‐based seed harvesting strategies fostered greater socioeconomic integration of traditional communities in restoration projects and programs, which is an important bottleneck for the advance of ecological restoration, especially in developing countries. Finally, we discuss some of the limitations of the various strategies for obtaining planting stocks and the way forward for their improvement.
The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a systematic study of K-S(0) and K*(0) meson production at midrapidity in p + p, d + Au, and Cu + Cu collisions at root ...s(NN) = 200 GeV. The K-S(0) and K*(0) mesons are reconstructed via their K-S(0) -> pi(0)(-> gamma gamma) pi(0)(-> gamma gamma) and K*(0) -> K-+/-pi(-/+) decay modes, respectively. The measured transverse-momentum spectra are used to determine the nuclear modification factor of K-S(0) and K*(0) mesons in d + Au and Cu + Cu collisions at different centralities. In the d + Au collisions, the nuclear modification factor of K-S(0) and K*(0) mesons is almost constant as a function of transverse momentum and is consistent with unity, showing that cold-nuclear-matter effects do not play a significant role in the measured kinematic range. In Cu + Cu collisions, within the uncertainties no nuclear modification is registered in peripheral collisions. In central collisions, both mesons show suppression relative to the expectations from the p + p yield scaled by the number of binary nucleon-nucleon collisions in the Cu + Cu system. In the p(T) range 2-5 GeV/c, the strange mesons (K-S(0), K*(0)) similarly to the phi meson with hidden strangeness, showan intermediate suppression between the more suppressed light quark mesons (pi(0)) and the nonsuppressed baryons (p, (p) over bar). At higher transverse momentum, p(T) > 5 GeV/c, production of all particles is similarly suppressed by a factor of approximate to 2.
Quarkonium suppression in nucleus-nucleus collisions is a powerful tool to probe the density and temperature of the medium created in heavy ion collisions. Forward rapidity measurements in p(d)+Au ...collisions are essential to understand how quarkonium states are affected by initial state effects, formation time, and local particle multiplicity. Earlier measurements in Au+Au collisions showed a stronger suppression of forward J/ψ compared to mid-rapidity results, indicating the possibility of a smaller contribution of regenerated quarkonium states at forward rapidity. These proceedings report on the latest quarkonium studies performed by the PHENIX collaboration in the rapidity range 1.2<|y|<2.2.
At the Quark Matter 2018 conference, the PHENIX Collaboration gave 10 parallel talks and 19 posters on a wide variety of topics in small and large systems. In these proceedings we discuss a few key ...results shown at the conference.
Using the extraordinary versatility of RHIC in selecting different colliding species, the PHENIX experiment has collected data in p+Al, p+Au, d+Au, and 3He+Au collisions at 200 GeV center-of-mass ...energy and conducted a comprehensive set of anisotropic flow measurements. These geometry-controlled experiments provide a unique testing ground for theoretical models that produce azimuthal particle correlations based on initial- and/or final-state effects.
A complete set of triangular anisotropies of inclusive charged particles and final results on identified pion and proton v2(pT) are shown. The mass-ordered splitting in v2(pT) provides information about the role of early-stage collective flow and late-stage hadronic rescattering. Detailed model comparisons with all observables are discussed.
Here, we measured direct photons for pT < 5GeV/c in minimum bias and 0%–40% most-central events at midrapidity for Cu+Cu collisions at √sNN = 200GeV. The e+e– contribution from quasireal direct ...virtual photons has been determined as an excess over the known hadronic contributions in the e+e– mass distribution. A clear enhancement of photons over the binary scaled p + p fit is observed for pT < 4GeV/c in Cu+Cu data. The pT spectra are consistent with the Au + Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the p + p baseline are 285 ± 53(stat) ± 57(syst) MeV/c and 333 ± 72(stat) ± 45(syst) MeV/c for minimum bias and 0%–40% most-central events, respectively. The rapidity density, dN/dy, of photons demonstrates the same power law as a function of dNch/dη observed in Au + Au at the same collision energy.
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