Assessing the effectiveness of protected areas for panda conservation under future climate and land use change scenarios.

While the relatively stable land use and land cover (LULC) patterns is an important feature of protected areas (PAs), the influence of this feature on future species distribution and the effectiveness of the PAs has rarely been explored. Here, we assessed the role of land use patterns within PAs on the projected range of the giant panda (Ailuropoda melanoleuca) by comparing projections inside and outside of PAs for four model configurations: (1) only climate covariates, (2) climate and dynamic land use covariates, (3) climate and static land use covariates and (4) climate and hybrid dynamic-static land use covariates. Our objectives were twofold: to understand the role of protected status on projected panda habitat suitability and evaluate the relative efficacy of different climate modeling approaches. The climate and land use change scenarios used in the models include two shared socio-economic pathways (SSPs) scenarios: SSP126 [an optimistic scenario] and SSP585 [a pessimistic scenario]. We found that models including land-use covariates performed significantly better than climate-only models and that these projected more suitable habitat than climate-only models. Static land-use models projected more suitable habitat than both the dynamic and hybrid models under SSP126, while these models did not differ under SSP585. China's panda reserve system was projected to effectively maintain suitable habitat inside PAs. Panda dispersal ability also significantly impacted outcomes, with most models assuming unlimited dispersal forecasting range expansion and models assuming zero dispersal consistently forecasting range contraction. Our findings highlight that policies targeting improved land-use practices should be an effective means for offsetting some of the negative effects of climate change on pandas. As the effectiveness of PAs is projected to be maintained, we recommend the judicious management and expansion of the PA system to ensure the resilience of panda populations into the future.

Efficient Experimental Verification of Quantum Gates with Local Operations.

Verifying the correct functioning of quantum gates is a crucial step toward reliable quantum information processing, but it becomes an overwhelming challenge as the system size grows due to the dimensionality curse. Recent theoretical breakthroughs show that it is possible to verify various important quantum gates with the optimal sample complexity of O(1/ε) using local operations only, where ε is the estimation precision. In this Letter, we propose a variant of quantum gate verification (QGV) that is robust to practical gate imperfections and experimentally realize efficient QGV on a 2-qubit controlled-not gate and a 3-qubit Toffoli gate using only local state preparations and measurements. The experimental results show that, by using only 1600 and 2600 measurements on average, we can verify with 95% confidence level that the implemented controlled-not gate and Toffoli gate have fidelities of at least 99% and 97%, respectively. Demonstrating the superior low sample complexity and experimental feasibility of QGV, our work promises a solution to the dimensionality curse in verifying large quantum devices in the quantum era.

"Super-Heisenberg" and Heisenberg Scalings Achieved Simultaneously in the Estimation of a Rotating Field.

The Heisenberg scaling, which scales as N^{-1} in terms of the number of particles or T^{-1} in terms of the evolution time, serves as a fundamental limit in quantum metrology. Better scalings, dubbed as "super-Heisenberg scaling," however, can also arise when the generator of the parameter involves many-body interactions or when it is time dependent. All these different scalings can actually be seen as manifestations of the Heisenberg uncertainty relations. While there is only one best scaling in the single-parameter quantum metrology, different scalings can coexist for the estimation of multiple parameters, which can be characterized by multiple Heisenberg uncertainty relations. We demonstrate the coexistence of two different scalings via the simultaneous estimation of the magnitude and frequency of a field where the best precisions, characterized by two Heisenberg uncertainty relations, scale as T^{-1} and T^{-2}, respectively (in terms of the standard deviation). We show that the simultaneous saturation of two Heisenberg uncertainty relations can be achieved by the optimal protocol, which prepares the optimal probe state, implements the optimal control, and performs the optimal measurement. The optimal protocol is experimentally implemented on an optical platform that demonstrates the saturation of the two Heisenberg uncertainty relations simultaneously, with up to five controls. As the first demonstration of simultaneously achieving two different Heisenberg scalings, our study deepens the understanding on the connection between the precision limit and the uncertainty relations, which has wide implications in practical applications of multiparameter quantum estimation.

Climate change and landscape-use patterns influence recent past distribution of giant pandas.

Climate change is one of the most pervasive threats to biodiversity globally, yet the influence of climate relative to other drivers of species depletion and range contraction remain difficult to disentangle. Here, we examine climatic and non-climatic correlates of giant panda (Ailuropoda melanoleuca) distribution using a large-scale 30 year dataset to evaluate whether a changing climate has already influenced panda distribution. We document several climatic patterns, including increasing temperatures, and alterations to seasonal temperature and precipitation. We found that while climatic factors were the most influential predictors of panda distribution, their importance diminished over time, while landscape variables have become relatively more influential. We conclude that the panda's distribution has been influenced by changing climate, but conservation intervention to manage habitat is working to increasingly offset these negative consequences.

Experimental Optimal Orienteering via Parallel and Antiparallel Spins.

Antiparallel spins are superior in orienteering to parallel spins. This intriguing phenomenon is tied to entanglement associated with quantum measurements rather than quantum states. Using photonic systems, we experimentally realize the optimal orienteering protocols based on parallel spins and antiparallel spins, respectively. The optimal entangling measurements for decoding the direction information from parallel spins and antiparallel spins are realized using photonic quantum walks, which is a useful idea that is of wide interest in quantum information processing and foundational studies. Our experiments clearly demonstrate the advantage of antiparallel spins over parallel spins in orienteering. In addition, entangling measurements can extract more information than local measurements even if no entanglement is present in the quantum states.

Minimizing Backaction through Entangled Measurements.

When an observable is measured on an evolving coherent quantum system twice, the first measurement generally alters the statistics of the second one, which is known as measurement backaction. We introduce, and push to its theoretical and experimental limits, a novel method of backaction evasion, whereby entangled collective measurements are performed on several copies of the system. This method is inspired by a similar idea designed for the problem of measuring quantum work [Perarnau-Llobet et al., Phys. Rev. Lett. 118, 070601 (2017)PRLTAO0031-900710.1103/PhysRevLett.118.070601]. By using entanglement as a resource, we show that the backaction can be extremely suppressed compared to all previous schemes. Importantly, the backaction can be eliminated in highly coherent processes.

Investigation on Surface Tilting in the Failure Process of Shallow Landslides.

In recent decades, early warning systems to predict the occurrence of landslides using tilt sensors have been developed and employed in slope monitoring due to their low cost and simple installation. Although many studies have been carried out to validate the efficiency of these early warning systems, few studies have been carried out to investigate the tilting direction of tilt sensors at the slope surface, which have revealed controversial results in field monitoring. In this paper, the tilting direction and the pre-failure tilting behavior of slopes were studied by performing a series of model tests as well as two field tests. These tests were conducted under various testing conditions. Tilt sensors with different rod lengths were employed to investigate the mechanism of surface tilting. The test results show that the surface tilting measured by the tilt sensors with no rods and those with short rods located above the slip surface are consistent, while the tilting monitored by the tilt sensors with long rods implies an opposite rotational direction. These results are important references to understand the controversial surface tilting behavior in in situ landslide monitoring cases and imply the correlation between the depth of the slip surface of the slope and the surface tilting in in situ landslide monitoring cases, which can be used as the standard for tilt sensor installation in field monitoring.

Control-Enhanced Sequential Scheme for General Quantum Parameter Estimation at the Heisenberg Limit.

The advantage of quantum metrology has been experimentally demonstrated for phase estimations where the dynamics are commuting. General noncommuting dynamics, however, can have distinct features. For example, the direct sequential scheme, which can achieve the Heisenberg scaling for the phase estimation under commuting dynamics, can have even worse performances than the classical scheme when the dynamics are noncommuting. Here we realize a scalable optimally controlled sequential scheme, which can achieve the Heisenberg precision under general noncommuting dynamics. We also present an intuitive geometrical framework for the controlled scheme and identify sweet spots in time at which the optimal controls used in the scheme can be prefixed without adaptation, which simplifies the experimental protocols significantly. We successfully implement the scheme up to eight controls in an optical platform and demonstrate a precision near the Heisenberg limit. Our work opens the avenue for harvesting the power of quantum control in quantum metrology, and provides a control-enhanced recipe to achieve the Heisenberg precision under general noncommuting dynamics.

Evaluation of Soil Moisture and Shear Deformation Based on Compression Wave Velocities in a Shallow Slope Surface Layer.

Rainfall-induced landslides occur commonly in mountainous areas around the world and cause severe human and infrastructural damage. An early warning system can help people safely escape from a dangerous area and is an economical and effective method to prevent and mitigate rainfall-induced landslides. This paper proposes a method to evaluate soil moisture and shear deformation by compression wave velocities in a shallow slope surface layer. A new type of exciter and new receivers have been developed using a combination of micro electro-mechanical systems (MEMS) accelerometers and the Akaike's information criterion (AIC) algorithm, which can automatically calculate the elastic wave travel time with accuracy and reliability. Laboratory experiments using a multi-layer shear model were conducted to reproduce the slope failure. The relationships between wave velocities and soil moisture were found to be dependent on the saturation path (rain or drain); in other words, hysteresis was observed. The wave velocity ratio reduced by 0.1-0.2 when the volumetric water content (VWC) increased from 0.1 to 0.27 m3/m3. When loading the shear stress corresponding to slope angles of 24, 27, 29, or 31 degrees, a drop of 0.2-0.3 in wave velocity ratio was observed at the middle layer, and near 0.5 at the bottom layer. After setting the shear stress to correspond to a slope angle of 33 degrees, the displacement started increasing and finally, slope failure occurred. With increasing displacement, the wave velocities also decreased rapidly. The wave velocity ratio dropped by 0.2 after a displacement of 3 mm. Monitoring long-term elastic wave velocities in a slope surface layer allows one to observe the behavior of the slope, understand its stability, and then apply an early warning system to predict slope failure.

Evaluating the vulnerability of Tetracentron sinense habitats to climate-induced latitudinal shifts.

Exploring the changing process of the geographical distribution pattern of Tetracentron sinense Oliv. and its main influencing factors since the last interglacial period can provide a scientific basis for the effective protection and management of the species. The MaxEnt model was used to construct the potential distribution areas of T. sinense in different periods such as the last interglacial (LIG), the last glacial maximum (LGM), the mid-Holocene (MID), and the current and future (2050s and 2070s). On the premise of discussing the influence of dominant environmental factors on its distribution model, the suitable area changes of T. sinense under different ecological climate situations were quantitatively analyzed. (1) The AUC and TSS values predicted by the optimized model were 0.959 and 0.835, respectively, indicating a good predictive effect by the MaxEnt model; the potential suitable areas for T. sinense in the current period are mainly located in Southwest China, which are wider compared to the actual habitats. (2) Jackknife testing showed that the lowest temperature in the coldest month (Bio6), elevation (Elev), seasonal variation coefficient of temperature (Bio4), and surface calcium carbonate content (T-CACO3) are the dominant environmental factors affecting the distribution of T. sinense. (3) From the last interglacial period to the current period, the total suitable area of T. sinense showed a decreasing trend; the distribution points of T. sinense populations in mid-Holocene period may be the origin of the postglacial population, and Southwest China may be its glacial biological refuge. (4) Compared with the current period, the total suitable area ranges of T. sinense in China in the 2050s and 2070s decreased, and the centroid location of its total fitness area all migrated to the northwest, with the largest migration distance in 2070s under the SSPs 7.0 climate scenario. Temperature was the principal factor influencing the geographical distribution of T. sinense. With global warming, the range of T. sinense suitable areas will show a shrinking trend, with a shift toward higher-latitude regions. Ex situ conservation measures could be taken to preserve its germplasm resources.

SOC estimation of lead-carbon battery based on GA-MIUKF algorithm.

The paper proposes a SOC (State of Charge) estimation method for lead-carbon batteries based on the GA-MIUKF algorithm. The GA-MIUKF algorithm combines GA (Genetic Algorithm) for global search and optimization with the MI-UKF (Multi-innovation Unscented Kalman Filter) algorithm for estimating the SOC of lead-carbon batteries. By establishing an equivalent circuit model for the battery, the GA is employed to globally search and optimize the battery model parameters and the noise variance parameters in the MI-UKF algorithm. Comparative analyses with the UKF (Unscented Kalman Filter) algorithms and MI-UKF algorithms reveal that the SOC estimation method based on the GA-MIUKF algorithm yields more accurate results for lead-carbon battery SOC estimation, with an average estimation error of 2.0%. This highlights the efficacy of the proposed approach in enhancing SOC estimation precision.

Centrifuge tests on the deformation law of pipelines crossing slopes with different water contents.

The deformation law of pipelines crossing landslide areas is an important prerequisite for the scientific design of pipelines. Most current studies find it difficult to simulate the real stress and strain state of pipelines on site. This study conducted two centrifuge model tests to observe pipeline failure indicators (deformation, stress, strain) and slope failure indicators (crack width, soil pressure, landslide displacement) in response to changes in acceleration. The experimental findings align with the results obtained from numerical simulations. The findings indicate that slope failure with high moisture content is more serious. At a moisture content of 15%, the slope has a maximum displacement of 70 mm in close reach to the buried pipeline. The pipeline has a "bimodal distribution" of strain along its axial length. The largest amount of deformation occurs at a distance of L/4 from the center of the pipeline, and the deformation value is 9000 µÎµ. Moreover, the maximum deformation in the mid-span is 21 mm, which corresponds to the result accumulated from the numerical simulation. Thus, the pipeline needs to improve the disaster prevention capabilities at the mid-span and L/4 of the pipeline.

Hybrid niche-neutral models outperform an otherwise equivalent neutral model for fitting coral reef data.

Niche theory and neutral theory are two major developments aiming at explaining patterns of biodiversity observed in nature. Both theories have been found relevant either separately or simultaneously in some real communities, and it has been theoretically demonstrated that they can produce similar species abundance distributions. However, it remains controversial whether the two theories can produce similar patterns via different mechanisms, or can interact to jointly produce the observed diversity patterns, or whether the patterns generated by the neutral model are robust to niche structure. Here we show that, although the neutral model proposed for spatially discrete communities remains robust to strong niche structure for high-diversity communities, the inclusion of more realistic niche differentiation modes greatly improves the goodness of fit to Indo-Pacific coral reefs. Actually, the multiple discrete communities' neutral model, due to its underestimation of the number or abundance of common species, fails to capture the combination of many rare species and a few highly abundant species that characterize the Indo-Pacific coral reef communities. By incorporating niche structure into the multiple discrete communities' model, the hybrid niche-neutral models can successfully reproduce both the species-based and individual-based abundance distribution patterns observed in the coral reefs. We proposed that both niche theory and neutral theory may be involved in explaining the structure of such communities. Our results also suggest a negative relationship between per capita birth to death ratio and immigration among different guilds of coral species, which clearly deserves further investigation.

Comparative analysis of trophic niche using stable isotopes provides insight into resource use of giant pandas.

Trophic niche is the result of the long-term evolution of species and can reflect the pressures they experience in habitats. The whole-genome sequencing of giant pandas (Ailuropoda melanoleuca) has indicated that populations distributed in Qinling (QIN) and non-QIN probably diverged 300 ky ago. Although many studies regarding foraging strategy, habitat preference, and niche partition have been conducted on these populations, there is still a lack of precise quantification of trophic niches. Here, we calculated and compared isotopic trophic niche widths of giant pandas from Sichuan (SC) and QIN populations by measuring carbon and nitrogen isotopes of their hairs; combined with data from sympatric mammals, we explored the relative trophic positions of giant pandas in the ecosystem, respectively. The Stable Isotope Bayesian Ellipses in R (SIBER) model results showed the trophic niche width of QIN pandas was 3.44‰2 , which was significantly bigger than those of the SC population (2.03‰2 ), with an overlapping about 1.45‰2 ; and they both occupied a unique position in the context, almost one trophic level lower than herbivores. Then, we determined the isotopic ratios of the main foods from the habitats of these pandas; the results suggested that the isotopic difference between bamboo shoots and other parts plus the various feeding selections of pandas on them accounted for pandas' trophic niche widths. We considered the higher nutrition availability and digestible food resources giving QIN pandas a wider trophic niche than pandas from SC. This conclusion provides a new insight into the resource use and trophic ecology of giant pandas and is important to develop refined management plans for the two populations.

Surface engineering of Al2O3 nanotubes by ureasolysis method for activating persulfate degradation of antibiotics.

Though ecofriendly, pure Al2O3 has never been used for activation of peroxodisulfate (PDS) to degrade pollutants. We report the fabrication of Al2O3 nanotubes by ureasolysis method for efficient activating PDS degradation of antibiotics. The fast ureasolysis in aqueous AlCl3 solution produces NH4Al(OH)2CO3 nanotubes, which are calcined to porous Al2O3 nanotubes, and the release of ammonia and carbon dioxide engineers the surface features of large surface area, numerous acidic-basic sites and suitable Zeta potentials. The synergy of these features facilitates the adsorption of the typical antibiotics ciprofloxacin and PDS activation, which is proved by experiment results and density functional theory simulation. The proposed Al2O3 nanotubes can catalyze 92-96% degradation of 10 ppm ciprofloxacin within 40 min, with chemical oxygen demand removal of 65-66% in aqueous, and 40-47% in whole including aqueous and catalysts. Ciprofloxacin at high concentration, other fluoroquinolones and tetracycline can also be effectively degraded. These data demonstrate the Al2O3 nanotubes prepared by the nature-inspired ureasolysis method has unique features and great potentials for antibiotics degradation.

Forecasting the combined effects of future climate and land use change on the suitable habitat of Davidia involucrata Baill.

Accurately predicting the future distribution of species is crucial for understanding how species will response to global environmental change and for evaluating the effectiveness of current protected areas (PAs). Here, we assessed the effect of climate and land use change on the projected suitable habitats of Davidia involucrata Baill under different future scenarios using the following two types of models: (a) only climate covariates (climate SDMs) and (b) climate and land use covariates (full SDMs). We found that full SDMs perform significantly better than climate SDMs in terms of both AUC (p < .001) and TSS (p < .001) and also projected more suitable habitat than climate SDMs both in the whole study area and in its current suitable range, although D. involucrate is predicted to loss at least 26.96% of its suitable area under all future scenarios. Similarly, we found that these range contractions projected by climate SDMs would negate the effectiveness of current PAs to a greater extent relative to full SDMs. These results suggest that although D. involucrate is extremely vulnerability to future climate change, conservation intervention to manage habitat may be an effective option to offset some of the negative effects of a changing climate on D. involucrate and can improve the effectiveness of current PAs. Overall, this study highlights the necessity of integrating climate and land use change to project the future distribution of species.

Large variability in response to future climate and land-use changes among Chinese Theaceae species.

Theaceae is an important family in the phylogeny of angiosperm in China, which are potentially threatened by future changes in climatic and land use conditions. Therefore, understanding and predicting the isolated and combined effects of these two global change factors on Theaceae species is crucial for biodiversity conservation. Here, we assessed the isolated and combined effects of climate and land use change on the distribution shifts of 95 Theaceae species under different future scenarios by comparing projections of three model configurations: (1) dynamics climate and constant land use variables; (2) constant climate and dynamics land use variables; and (3) dynamics climate and dynamics land use variables. We find that all the three types of models predicted range contractions for most of the 95 Theaceae species under all future scenarios. Moreover, we find that climate change has rather strong effect for most species while land use change has nonsignificant or weak effect on future species distributions, although both of these two isolated effects are highly variable across individual species. Finally, the combined effect of these two factors reveals that the land use change may amplify or buffer distribution shifts expected from climate change impact depending on species. These findings emphasize the importance of taking into account the large variability in response to land use change among Theaceae species when developing land-based conservation strategies in a changing climate.

Predicting range shifts of the giant pandas under future climate and land use scenarios.

Understanding and predicting how species will respond to global environmental change (i.e., climate and land use change) is essential to efficiently inform conservation and management strategies for authorities and managers. Here, we assessed the combined effect of future climate and land use change on the potential range shifts of the giant pandas (Ailuropoda melanoleuca) in Sichuan Province, China. We used species distribution models (SDMs) to forecast range shifts of the giant pandas by the 2050s and 2070s under four combined climate and land use change scenarios. We also compared the differences in distributional changes of giant pandas among the five mountains in the study area. Our SDMs exhibited good model performance and were not overfitted, with a mean Boyce index of 0.960 ± 0.015 and a mean omission rate of 0.002 ± 0.003, and suggested that precipitation seasonality, annual mean temperature, the proportion of forest cover, and total annual precipitation are the most important factors in shaping the current distribution pattern of the giant pandas. Our projections of future species distribution also suggested a range expansion under an optimistic greenhouse gas emission, while suggesting a range contraction under a pessimistic greenhouse gas emission. Moreover, we found that there is considerable variation in the projected range change patterns among the five mountains in the study area. Especially, the suitable habitat of the giant panda is predicted to increase under all scenarios in the Minshan mountains, while is predicted to decrease under all scenarios in Daxiangling and Liangshan mountains, indicating the vulnerability of the giant pandas at low latitudes. Our findings highlight the importance of an integrated approach that combines climate and land use change to predict the future species distribution and the need for a spatial explicit consideration of the projected range change patterns of target species for guiding conservation and management strategies.

Giant pandas' staple food bamboo phyllosphere fungal community and its influencing factors.

Giant pandas have developed a series of foraging strategies to adapt to their special bamboo diets. Although bamboo is an important food resource for giant pandas in Liziping National Nature Reserve (Liziping NR), China, there are relatively few studies on their phyllosphere fungal community and its influencing factors. Herein, we used ITS1 amplification and metagenomic sequencing to analyze the phyllosphere fungi diversity and functions (KEGG, CAZyme, and antibiotic resistance gene) and explore the influencing factors for the three giant pandas foraging bamboo species (Arundinaria spanostachya, AS; Yushania lineolate, YL; and Fargesia ferax, FF) over different seasons (spring vs. autumn) in Liziping NR, China. We found that Ascomycota and Basidiomycota were the most dominant phyla in the bamboo phyllosphere. The alpha diversity (e.g., the Sobs index and Shannon index) was relatively higher in autumn samples than in spring samples, and the community structure differed significantly between the three bamboo species in spring and autumn. Some biotic and abiotic variables (e.g., the elevation and mean base diameter of bamboo) significantly influenced the abundance, diversity, and community structure of the bamboo phyllosphere fungal community. Moreover, the functional analysis showed the differences in the glycoside hydrolase community and antibiotic resistance gene (ARG) profile between spring and autumn samples. Co-occurrence network modeling suggested that AS phyllosphere fungal communities in autumn employed a much more complex network than that in spring, and the abundance of multidrug, tetracycline, and glycopeptide resistance genes was high and closely correlated with other ARGs. These results indicate that fungal community's abundance, diversity, and community structure are mainly affected by the season, host species, and elevation. The season and host species are major factors affecting the biological functions (KEGG and CAZyme), ARGs, and interactions between sympatric bacterial and fungal communities in bamboo phyllosphere. This integrated study can provide a reference basis for the seasonal management of bamboo resources foraged by wild giant pandas, and predict the risk of antibiotic resistance in bamboo phyllosphere fungal flora in Liziping NR (Xiaoxiangling mountains), China.

The importance of niche differentiation for coexistence on large scales.

It is widely accepted that niche differentiation plays a key role in coexistence on relatively small scales. With regard to a large community scale, the recently propounded neutral theory suggests that species abundances are more influenced by history and chance than they are by interspecies competition. This inference is mainly based on the probability that competitive exclusion is largely slowed by recruitment limitation, which may be common in species rich communities. In this respect, a theoretical study conducted by Hurtt and Pacala (1995) for a niche differentiated community has been frequently cited to support neutral coexistence. In this paper, we focused on the effect of symmetric recruitment limitation on delaying species competitive exclusion caused by both symmetric and asymmetric competition in a large homogeneous habitat. By removing niche differentiation in space, we found that recruitment limitation could delay competitive exclusion to some extent, but the effect was rather limited compared to that predicted by Hurtt and Pacala's model for a niche differentiated community. Our results imply that niche differentiation may be important for species coexistence even on large scales and this has already been confirmed in some species rich communities.