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1. Abrupt transitions in a southwest USA desert grassland related to the P acific D ecadal O scillation

   https://doi.org/10.1002/ecy.4065  

   Christensen, Erica M.; James, Darren K.; Randall, Robb M.; Bestelmeyer, Brandon T. (May 2023, Ecology)

   Abstract Prediction of abrupt ecosystem transitions resulting from climatic change will be an essential element of adaptation strategies in the coming decades. In the arid southwest USA, the collapse and recovery of long‐lived perennial grasses have important effects on ecosystem services, but the causes of these variations have been poorly understood. Here we use a quality‐controlled vegetation monitoring dataset initiated in 1915 to show that grass cover dynamics during the 20th century were closely correlated to the Pacific decadal oscillation (PDO) index. The relationship out‐performed models correlating grasses to yearly precipitation and drought indices, suggesting that ecosystem transitions attributed only to local disturbances were instead influenced by climate teleconnections. Shifts in PDO phase over time were associated with the persistent loss of core grass species and recovery of transient species, so recovery of grasses in aggregate concealed significant changes in species composition. However, the relationship between PDO and grass cover broke down after 1995; grass cover is consistently lower than PDO would predict. The decoupling of grass cover from the PDO suggests that a threshold had been crossed in which warming or land degradation overwhelmed the ability of any grass species to recover during favorable periods. 

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2. Rainfall partitioning varies across a forest age chronosequence in the southern A ppalachian M ountains

   https://doi.org/10.1002/eco.2081  

   Brantley, Steven_T; Miniat, Chelcy_F; Bolstad, Paul_V (February 2019, Ecohydrology)

   Abstract Evaporation of precipitation from plant surfaces, or interception, is a major component of the global water budget. Interception has been measured and/or modelled across a wide variety of forest types; however, most studies have focused on mature, second‐growth forests, and few studies have examined interception processes across forest age classes. We present data on two components of interception, total canopy interception (E_i) and litter interception—that is, O_i + O_ehorizon layers—(E_ff), across a forest age chronosequence, from 2 years since harvest to old growth. We used precipitation, throughfall, and stemflow collectors to measure total rainfall (P) and estimateE_i; and collected litter biomass and modelled litter wetting and drying to estimate evaporative loss from litter. CanopyE_i,Pminus throughfall, increased rapidly with forest age and then levelled off to a maximum of 21% ofPin an old‐growth site. Stemflow also varied across stands, with the highest stemflow (~8% ofP) observed in a 12‐year‐old stand with high stem density. ModelledE_ffwas 4–6% ofPand did not vary across sites. Total stand‐level interception losses (E_i + E_ff) were best predicted by stand age (R² = 0.77) rather than structural parameters such as basal area (R² = 0.49) or leaf area (R² < 0.01). Forest age appears to be an important driver of interception losses from forested mountain watersheds even when stand‐level structural variables are similar. These results will contribute to our understanding of water budgets across the broader matrix of forest ages that characterize the modern forest landscape. 

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3. Vps501, a novel vacuolar SNX‐BAR protein cooperates with the SEA complex to regulate TORC1 signaling

   https://doi.org/10.1111/tra.12833  

   Goyal, Shreya; Segarra, Verónica A.; Nitika; Stecher, Aaron M.; Truman, Andrew W.; Reitzel, Adam M.; Chi, Richard J. (April 2022, Traffic)
4. SNAPSHOT USA 2021: A third coordinated national camera trap survey of the U nited S tates

   https://doi.org/10.1002/ecy.4318  

   Shamon, Hila; Maor, Roi; Cove, Michael_V; Kays, Roland; Adley, Jessie; Alexander, Peter_D; Allen, David_N; Allen, Maximilian_L; Appel, Cara_L; Barr, Evan; et al (May 2024, Ecology)

   Abstract SNAPSHOT USA is a multicontributor, long‐term camera trap survey designed to survey mammals across the United States. Participants are recruited through community networks and directly through a website application (https://www.snapshot-usa.org/). The growing Snapshot dataset is useful, for example, for tracking wildlife population responses to land use, land cover, and climate changes across spatial and temporal scales. Here we present the SNAPSHOT USA 2021 dataset, the third national camera trap survey across the US. Data were collected across 109 camera trap arrays and included 1711 camera sites. The total effort equaled 71,519 camera trap nights and resulted in 172,507 sequences of animal observations. Sampling effort varied among camera trap arrays, with a minimum of 126 camera trap nights, a maximum of 3355 nights, a median 546 nights, and a mean 656 ± 431 nights. This third dataset comprises 51 camera trap arrays that were surveyed during 2019, 2020, and 2021, along with 71 camera trap arrays that were surveyed in 2020 and 2021. All raw data and accompanying metadata are stored on Wildlife Insights (https://www.wildlifeinsights.org/), and are publicly available upon acceptance of the data papers. SNAPSHOT USA aims to sample multiple ecoregions in the United States with adequate representation of each ecoregion according to its relative size. Currently, the relative density of camera trap arrays varies by an order of magnitude for the various ecoregions (0.22–5.9 arrays per 100,000 km²), emphasizing the need to increase sampling effort by further recruiting and retaining contributors. There are no copyright restrictions on these data. We request that authors cite this paper when using these data, or a subset of these data, for publication. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the US Government. 

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5. The femora of Drepanosauromorpha ( Reptilia : Diapsida ): Implications for the functional evolution of the thigh of Sauropsida

   https://doi.org/10.1002/ar.25160  

   Pritchard, Adam C.; Irmis, Randall B.; Olori, Jennifer C.; Nesbitt, Sterling J.; Smith, Nathan D.; Stocker, Michelle R.; Turner, Alan H. (February 2023, The Anatomical Record)

   Abstract The femora of diapsids have undergone morphological changes related to shifts in postural and locomotor modes, such as the transition from plesiomorphic amniote and diapsid taxa to the apomorphic conditions related to a more erect posture within Archosauriformes. One remarkable clade of Triassic diapsids is the chameleon‐like Drepanosauromorpha. This group is known from numerous articulated but heavily compressed skeletons that have the potential to further inform early reptile femoral evolution. For the first time, we describe the three‐dimensional osteology of the femora of Drepanosauromorpha, based on undistorted fossils from the Upper Triassic Chinle Formation and Dockum Group of North America. We identify apomorphies and a combination of character states that link these femora to those in crushed specimens of drepanosauromorphs and compare our sample with a range of amniote taxa. Several characteristics of drepanosauromorph femora, including a hemispherical proximal articular surface, prominent asymmetry in the proximodistal length of the tibial condyles, and a deep intercondylar sulcus, are plesiomorphies shared with early diapsids. The femora contrast with those of most diapsids in lacking a crest‐like, distally tapering internal trochanter. They bear a ventrolaterally positioned tuberosity on the femoral shaft, resembling the fourth trochanter in Archosauriformes. The reduction of an internal trochanter parallels independent reductions in therapsids and archosauriforms. The presence of a ventrolaterally positioned trochanter is also similar to that of chameleonid squamates. Collectively, these features demonstrate a unique femoral morphology for drepanosauromorphs, and suggest an increased capacity for femoral adduction and protraction relative to most other Permo‐Triassic diapsids. 

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