Search for: All records

Groundwater extraction compromises the function of groundwater-dependent ecosystems, such as freshwater wetlands. Identifying whether groundwater conservation restores wetland hydrology is a first step toward rehabilitating impaired wetlands. In the Tampa Bay region of Florida (U.S.), groundwater extraction rates have been declining since 1998, partly in response to desiccation of wetlands and waterbodies. This study uses monthly water-level data from 152 depressional wetlands over 28 years (1991–2018) to identify trends in wetland inundation, determine whether those trends vary among wetlands historically exposed to different rates of groundwater extraction, and describe relationships between the timing and extent of cutbacks in groundwater extraction and the timing and extent of changes in wetland inundation. Many wetlands (57 %) exhibited increased inundation in response to cutbacks in groundwater extraction, indicating that water conservation measures are inducing recovery. Further, increased inundation began in most wetlands immediately upon, or within two years of, the time extraction cutbacks occurred, although some recovering wetlands exhibited longer lags. An additional 26 % of wetlands had steady-state water levels with inundation similar to that of reference wetlands, potentially revealing a population of wetlands hydrologically unimpaired by nearby groundwater extraction. Another subset of wetlands (14 %) with steady-state water depths exhibited increasing deviations from basin-full water levels, suggesting subsidence of the wetland basin. Active intervention beyond cutbacks in groundwater extraction may be necessary to restore this subset, whereas passive restoration (reducing extraction) appears adequate for the majority of impacted wetlands. Rising water levels may amplify surface-water connections among wetlands, with ecological and biogeochemical consequences both for individual wetlands and for the whole wetlandscape. As a host of human activities continue to rely on groundwater extraction, this study demonstrates the potential for, as well as variability in, hydrological recovery across a wetland-rich, low-relief landscape following the enactment of water conservation policies. 

The primate dorsolateral prefrontal cortex (DLPFC) displays unique in vivo activity patterns, but how in vivo activity regulates DLPFC pyramidal neuron (PN) properties remains unclear. We assessed the effects of in vivo Kir2.1 overexpression, a genetic silencing tool, on synapses in monkey DLPFC PNs. We show for the first time that recombinant ion channel expression successfully modifies the excitability of primate cortex neurons, producing effects on synaptic properties apparently different from those in the rodent cortex. 

Fire is a key disturbance process that shapes the structure and function of montane temperate rainforest in the Pacific Northwest (PNW). Recent research is revealing more frequent historical fire activity in the western central Cascades than expected by conventional theory. Indigenous peoples have lived in the PNW for millennia. However, Indigenous people's roles in shaping vegetation mosaics in montane temperate forests of the PNW has been overlooked, despite archaeological evidence of long-term, continuous human use of these landscapes. In this paper, we present a generalizable research framework for overcoming biases often inherent in historical fire research. The framework centers Indigenous perspectives and ethnohistory, leveraging theory in human ecology and archaeology to interpret fire histories. We apply this framework to place-based, empirical evidence of Indigenous land use and dendroecological fire history. Our framework leads us to conclude that the most parsimonious explanation for the occurrence of historical high fire frequency in the western Cascades is Indigenous fire stewardship. Further, our case study makes apparent that scholars can no longer ignore the role of Indigenous people in driving montane forest dynamics in the PNW. 

Wetlands provide essential ecosystem services, including nutrient cycling, flood protection, and biodiversity support, that are sensitive to changes in wetland hydrology. Wetland hydrological inputs come from precipitation, groundwater discharge, and surface run-off. Changes to these inputs via climate variation, groundwater extraction, and land development may alter the timing and magnitude of wetland inundation. Here, we use a long-term (14-year) comparative study of 152 depressional wetlands in west-central Florida to identify sources of variation in wetland inundation during two key time periods, 2005–2009 and 2010–2018. These time periods are separated by the enactment of water conservation policies in 2009, which included regional reductions in groundwater extraction. We investigated the response of wetland inundation to the interactive effects of precipitation, groundwater extraction, surrounding land development, basin geomorphology, and wetland vegetation class. Results show that water levels were lower and hydroperiods were shorter in wetlands of all vegetation classes during the first (2005–2009) time period, which corresponded with low rainfall conditions and high rates of groundwater extraction. Under water conservation policies enacted in the second (2010–2018) time period, median wetland water depths increased 1.35 m and median hydroperiods increased from 46 % to 83 %. Water-level variation was additionally less sensitive to groundwater extraction. The increase in inundation differed among vegetation classes with some wetlands not displaying signs of hydrological recovery. After accounting for effects of several explanatory factors, inundation still varied considerably among wetlands, suggesting a diversity of hydrological regimes, and thus ecological function, among individual wetlands across the landscape. Policies seeking to balance human water demand with the preservation of depressional wetlands would benefit by recognizing the heightened sensitivity of wetland inundation to groundwater extraction during periods of low precipitation. 

ImportanceThe risk of mental disorders is consistently associated with variants inCACNA1C(L-type calcium channel Cav1.2) but it is not known why these channels are critical to cognition, and whether they affect the layer III pyramidal cells in the dorsolateral prefrontal cortex that are especially vulnerable in cognitive disorders. ObjectiveTo examine the molecular mechanisms expressed in layer III pyramidal cells in primate dorsolateral prefrontal cortices. Design, Setting, and ParticipantsThe design included transcriptomic analyses from human and macaque dorsolateral prefrontal cortex, and connectivity, protein expression, physiology, and cognitive behavior in macaques. The research was performed in academic laboratories at Yale, Harvard, Princeton, and the University of Pittsburgh. As dorsolateral prefrontal cortex only exists in primates, the work evaluated humans and macaques. Main Outcomes and MeasuresOutcome measures included transcriptomic signatures of human and macaque pyramidal cells, protein expression and interactions in layer III macaque pyramidal cells using light and electron microscopy, changes in neuronal firing during spatial working memory, and working memory performance following pharmacological treatments. ResultsLayer III pyramidal cells in dorsolateral prefrontal cortex coexpress a constellation of calcium-related proteins, delineated byCALB1(calbindin), and high levels ofCACNA1C(Cav1.2),GRIN2B(NMDA receptor GluN2B), andKCNN3(SK3 potassium channel), concentrated in dendritic spines near the calcium-storing smooth endoplasmic reticulum. L-type calcium channels influenced neuronal firing needed for working memory, where either blockade or increased drive by β1-adrenoceptors, reduced neuronal firing by a mean (SD) 37.3% (5.5%) or 40% (6.3%), respectively, the latter via SK potassium channel opening. An L-type calcium channel blocker or β1-adrenoceptor antagonist protected working memory from stress. Conclusions and RelevanceThe layer III pyramidal cells in the dorsolateral prefrontal cortex especially vulnerable in cognitive disorders differentially express calbindin and a constellation of calcium-related proteins including L-type calcium channels Cav1.2 (CACNA1C), GluN2B-NMDA receptors (GRIN2B), and SK3 potassium channels (KCNN3), which influence memory-related neuronal firing. The finding that either inadequate or excessive L-type calcium channel activation reduced neuronal firing explains why either loss- or gain-of-function variants inCACNA1Cwere associated with increased risk of cognitive disorders. The selective expression of calbindin in these pyramidal cells highlights the importance of regulatory mechanisms in neurons with high calcium signaling, consistent with Alzheimer tau pathology emerging when calbindin is lost with age and/or inflammation. 

Cortinarius watsoneae, a new species in subgenus Myxacium, sect. Myxacium, is described from pine and mixed pine and hardwood forests from the Gulf States region of North America. It is characterized by the young lamellae that are grayish violet to pale violet, and relatively large basidiospores in comparison to C. mucosus. The ITS sequence is distinct from other members of sect. Myxacium, with 97% similarity to the closest known species, C. collinitus and C. mucosus. The new species is named in honor of the late Geraldine Watson. 

Abstract Upside-down jellyfish, genusCassiopea(Péron and Lesueur, 1809), are found in shallow coastal habitats in tropical and subtropical regions circumglobally. These animals have previously been demonstrated to produce flow both in the water column as a feeding current, and in the interstitial porewater, where they liberate porewater at rates averaging 2.46 mL h⁻¹. Since porewater inCassiopeahabitat can be nutrient-rich, this is a potential source of nutrient enrichment in these ecosystems. This study experimentally determines that porewater release byCassiopeasp. jellyfish is due to suction pumping, and not the Bernoulli effect. This suggests porewater release is directly coupled to bell pulsation rate, and unlike vertical jet flux, should be unaffected by population density. In addition, we show that bell pulsation rate is positively correlated with temperature, and negatively correlated with animal size. As such, we would predict an increase in the release of nutrient-rich porewater during the warm summer months. Furthermore, we show that, at our field site in Lido Key, Florida, at the northernmost limit ofCassiopearange, population densities decline during the winter, increasing seasonal differences in porewater release.