Kathleen Ann Lohse

Idaho State University | ISU · Department of Biological Sciences

Plant respiration and photosynthesis are the two main processes influencing carbon (C) flux balance at leaf‐to‐ecosystem scales. The ratio of respiration to photosynthesis (R:A) or carbon use efficiency (CUE) is considered an important trait for determining global carbon storage in the near future. One school of thought assumes that R:A is constant...

Geologic, geomorphic, and climatic factors have been hypothesized to influence where streams dry, but hydrologists struggle to explain the temporal drivers of drying. Few hydrologists have isolated the role that vegetation plays in controlling the timing and location of stream drying in headwater streams. We present a distributed, fine-scale water...

The Reynolds Creek Experimental Watershed (RCEW) and Critical Zone Observatory (CZO), located south of the western Snake River Plain in the Intermountain West of the United States, is the site of over 60 years of research aimed at understanding integrated earth processes in a semi‐arid climate to aid sustainable use of environmental resources. Mete...

The critical zone has been the subject of much discussion and debate as a term in the ecosystem, soil and earth system science communities, and there is a need to reconcile how this term is used within these disciplines. I suggest that much like watershed and soil ecosystems, the critical zone is an ecosystem and is defined by deeper spatial and te...

Biochar is a multifunctional soil conditioner capable of enhancing soil health and crop production while reducing greenhouse gas emissions. Understanding how soil microbes respond to biochar amendment is a vital step towards precision biochar application. Here, we synthesized 3899 observations of 24 microbial responses from 61 primary studies, appl...

Soil inorganic carbon (SIC) constitutes ∼40–50% of the terrestrial soil carbon and is an integral part of the global carbon cycle. Rainfall is a primary factor controlling SIC accumulation; however, the distribution and hierarchy of controls on SIC development in arid and semi-arid regions is poorly understood. The Reynolds Creek Experimental Water...

Ecological theory predicts a pulse disturbance results in loss of soil organic carbon and short-term respiration losses that exceed recovery of productivity in many ecosystems. However, fundamental uncertainties remain in our understanding of ecosystem recovery where spatiotemporal variation in structure and function are not adequately represented...

Policy interest in socio‐ecological systems has driven attempts to define and map socio‐ecological zones (SEZs), that is, spatial regions, distinguishable by their conjoined social and bio‐geo‐physical characteristics. The state of Idaho, USA, has a strong need for SEZ designations because of potential conflicts between rapidly increasing and impac...

From hillslope to small catchment scales (< 50 km2), soil carbon management and mitigation policies rely on estimates and projections of soil organic carbon (SOC) stocks. Here we apply a process-based modeling approach that parameterizes the MIcrobial-MIneral Carbon Stabilization (MIMICS) model with SOC measurements and remotely sensed environmenta...

Long‐term (>20 y) suspended sediment (SS) and particulate organic carbon (POC) records are relatively rare and yet are necessary for understanding linkages between climate, erosion and carbon export. We estimated long‐term (>23 y) SS and POC yields from four nested catchments that ranged from <1 to 54 km ² in area across the Reynolds Creek Experime...

Numerous studies have examined bacterial communities in biological soil crusts (BSCs) associated with warm arid to semiarid ecosystems. Few, however, have examined bacterial communities in BSCs associated with cold steppe ecosystems, which often span a wide range of climate conditions and are sensitive to trends predicted by relevant climate models...

Non‐perennial streams comprise over half of the global stream network and impact downstream water quality. Although aridity is a primary driver of stream drying globally, surface flow permanence varies spatially and temporally within many headwater streams, suggesting that these complex drying patterns may be driven by topographic and subsurface fa...

Despite a multitude of small catchment studies, we lack a deep understanding of how variations in critical zone architecture lead to variations in hydrologic states and fluxes. This study characterizes hydrologic dynamics of 15 catchments of the U.S. Critical Zone Observatory (CZO) network where we hypothesized that our understanding of subsurface...

Stream drying and wildfire are projected to increase with climate change in the western United States, and both are likely to impact stream chemistry patterns and processes. To investigate drying and wildfire effects on stream chemistry (carbon, nutrients, anions, cations, and isotopes), we examined seasonal drying in two intermittent streams in so...

Streamflow in arid and semi-arid regions is predominantly temporary, an integral part of mountain block hydrology and of significant importance for groundwater recharge and biogeochemical processes. However, temporary streamflow regimes, especially ephemeral flow, remain poorly quantified. We use electrical resistance sensors and USGS stream gauge...

Ephemeral and intermittent streams are increasing with climate and land use changes, and alteration in stream water presence or flow duration will likely affect litter decomposition and nutrient dynamics in channel and riparian zones more than uplands. To investigate the influence of varying climate and streamflow regimes on rates of decomposition...

Big sagebrush (Artemisia tridentata) is a widespread and locally dominant shrub that is a key driver of water fluxes and storage in western North America. There are several recognized subspecies of big sagebrush that occupy different microsites across the landscape according to moisture availability, yet little is known about how these subspecies v...

Chemical stabilization of microbial-derived products such as extracellular enzymes (EE) onto mineral surfaces has gained attention as a possibly important mechanism leading to the persistence of soil organic carbon (SOC). While the controls on EE activities and their stabilization in the surface soil are reasonably well-understood, how these activi...

The lasting influence humans have on Earth’s critical zone—and how geologic forces have mediated those influences—is revealed in studies of soil and carbon migration.

Differences in water and carbon fluxes along a climate/elevation gradient within a sagebrush ecosystem are quantified, and inferences are made about climate warming using a network of eddy covariance systems. Sites are located within the Reynolds Creek Critical Zone Observatory in southwestern Idaho, USA, with elevations ranging from 1425 to 2111 m...

The projected shifts in winter weather and snowpack conditions are expected to impact carbon storage in western U.S. rangelands. Sagebrush shrublands comprise much of the western United States, yet contribution of winter CO2 efflux to the overall carbon budget of these ecosystems remains uncertain. We explored factors controlling winter CO2 efflux...

Wildfire is a natural component of sagebrush (Artemisia spp.) steppe rangelands that induces temporal shifts in plant community physiognomy, ground surface conditions, and erosion rates. Fire alteration of the vegetation structure and ground cover in these ecosystems commonly amplifies soil losses by wind‐ and water‐driven erosion. Much of the fire...

Sagebrush ecosystems consist of different communities of species and subspecies of sagebrush marked by distinct ecotones along elevation gradients, yet few studies have quantified how ecosystem-scale carbon dioxide (net ecosystem exchange, NEE) and water fluxes (evapotranspiration, ET), as well as their environmental drivers, vary among communities...

Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities wi...

While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also...

Large uncertainties in global carbon (C) budgets stem from soil carbon estimates and associated challenges in distributing soil organic carbon (SOC) at local to landscape scales owing to lack of information on soil thickness and controls on SOC storage. Here we show that 94% of the fine-scale variation in total profile SOC within a 1.8 km2 semi-ari...

Dryland ecosystems are experiencing shifts in rainfall and plant community composition, which are expected to alter cycling and storage of soil carbon (C). Few experiments have been conducted to examine long‐term effects on (1) soil organic C (SOC) pools throughout the soil profile, and (2) soil inorganic C (SIC) pools as they relate to dynamic cha...

The non-uniform distribution of water in snowdrift-driven systems can lead to spatial heterogeneity in vegetative communities and soil development, as snowdrifts may locally increase weathering. The focus of this study is to understand the coupled hydrological and biogeochemical dynamics in a heterogeneous, snowdrift-dominated headwater catchment (...

Core Ideas Long‐term watersheds may provide a coherent description of climate change impacts. Observatories provide a stable experimental platform for process model development. Local environmental gradients support high spatial resolution hydrological modeling. Long‐term hydrologic data support large scale biogeochemical process integration. Large...

The Acknowledgements contained an error: In the original statement “This research was supported by the National Science Foundation award IIA – 1301792 from the National Science Foundation Idaho Environmental Program to Stimulate Competitive Research Program.”. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

The impact of land management actions such as prescribed fire remains a key uncertainty in understanding the spatiotemporal patterns of carbon cycling in the Western USA. We therefore quantified carbon exchange and aboveground carbon stocks following a prescribed fire in a mountain big sagebrush ecosystem located in the northern Great Basin, USA. S...

Pedotransfer functions (PTFs) have been developed to estimate soil fine fraction bulk density (BDFF) using the relationships with soil organic carbon content (SOC) and particle size distribution. Current PTF's overlook the influence of lithology on BDFF estimations. In this study, we examine this influence by developing two PTF's for total bulk den...

Urbanization has a massive impact on ecological function and impedes the provisioning of environmental services. The interaction between urbanization and the environment has been researched extensively. However, the existing research focused on the urbanization characteristics of large metropolitan areas. In this paper, we investigate the urban fra...

The Critical Zone (CZ, defined as the zone between the top of the vegetation canopy to the groundwater) mediates the impact of precipitation amount and timing on water availability and plant productivity. However, the spatial distribution of soil and subsurface structure is almost always poorly constrained leading to considerable uncertainty in the...

Soil thickness is a fundamental variable in many earth science disciplines due to its critical role in many hydrological and ecological processes, but it is difficult to predict. Here we show a strong linear relationship (r2 = 0.87, RMSE = 0.19 m) between soil thickness and hillslope curvature across both convergent and divergent parts of the lands...

Long-term environmental research networks are one approach to advancing local, regional, and global environmental science and education. A remarkable number and wide variety of environmental research networks operate around the world today. These are diverse in funding, infrastructure, motivating questions, scientific strengths, and the sciences th...

Thirty-one years of spatially distributed air temperature, relative humidity, dew point temperature, precipitation amount, and precipitation phase data are presented for the Reynolds Creek Experimental Watershed, which is part of the Critical Zone Observatory network. The air temperature, relative humidity, and precipitation amount data are spatial...

Climate-driven changes in carbon (C) cycling of forested ecosystems have the potential to alter long-term C sequestration and the global C balance. Prior studies have shown that C uptake and partitioning in response to hydrologic variation are system specific, suggesting that a comprehensive assessment is required for distinct ecosystems. Many sub-...

The distribution, transport, and accumulation of wildfire-generated pyrogenic carbon (PyC) has important consequences for contaminant transport and carbon cycling, but a conceptual model for PyC accumulation and loss that includes geomorphic processes is lacking. In this study we quantified PyC concentration in soil samples collected from the Jemez...

Collaborations between biologists and geologists are key to understanding and projecting how landscapes function and change over time. Such collaborations are stimulated by on-going scientific developments, advances in instrumentation and technology, and the growing recognition that environmental problems necessitate interdisciplinary investigation...

The critical zone (CZ), the dynamic living skin of the Earth, extends from the top of the vegetative canopy through the soil and down to fresh bedrock and the bottom of the groundwater. All humans live in and depend on the CZ. This zone has three co-evolving surfaces: the top of the vegetative canopy, the ground surface, and a deep subsurface below...

Biological soil crust (biocrust) is a composite of mosses, lichens, and bacteria that performs many important soil system functions, including increasing soil stability, protecting against wind erosion, reducing nutrient loss, and mediating carbon and nitrogen fixation cycles. These cold desert and steppe ecosystems are expected to experience direc...

In mountains with seasonal snow cover, the effects of climate change on snowpack will be constrained by landscape-vegetation interactions with the atmosphere. Airborne lidar surveys used to estimate snow depth, topography, and vegetation were coupled with reanalysis climate products to quantify these interactions and to highlight potential snowpack...

Thirty one years of spatially distributed air temperature, relative humidity, dew point temperature, precipitation amount, and precipitation phase data are presented for the Reynolds Creek Experimental Watershed, which is part of the Critical Zone Observatory network. The air temperature, relative humidity, and precipitation amount data are spatial...

In drylands worldwide, biological soil crusts (BSC) form a thin photosynthetic cover across landscapes, and provide vital benefits in terms of stabilizing soil and fixing nitrogen (N) and carbon (C). Numerous studies have examined the effects of climate and disturbance on BSC functions; however, few have characterized these responses in rolling BSC...

The critical zone (CZ), the dynamic living skin of the Earth, extends from the top of the vegetation canopy through the soil and down to fresh bedrock and the bottom of groundwater. All humans live in and depend on the critical zone. This zone has three co-evolving surfaces: the top of the vegetation canopy, the ground surface, and a deep subsurfac...

The storage and flux of carbon from soils, the planet's third largest carbon pool, strongly influence the global carbon cycle and are essential, but poorly constrained, parameters for global climate models. An estimated 40% of all soil carbon is stored as inorganic carbonate minerals. Despite a recognition of the importance of soil inorganic carbon...

Ephemeral streams are abundant in drylands, yet we know little about how their vegetation differs from surrounding terrestrial zones and about their projected response to regional warming and drying. We assessed plant communities at seven ephemeral streams (and terrestrial zones) distributed among three climatic settings in Arizona. Compared to ter...

The US National Science Foundation (NSF) has pioneered an integrated approach to the study of Earth's Critical Zone by supporting a network of Critical Zone Observatories (CZOs). The CZOs are intensively studied and monitored sites with a focus on a range of Critical Zone processes that are well represented at the various sites. The initial network...

Ungulates use habitat with differential microclimate characteristics; therefore, fecal inputs to a particular habitat may result in vastly different rates of decomposition and nutrient release. We tested this hypothesis and conducted a 1-year decomposition experiment where we deployed fecal samples from Shiras moose (Alces alces shirasi) and subseq...

Nitrogen (N) loading is a global stressor to fresh and salt water systems with cascading effects on ecosystem processes. However, it is unclear if generalized global response patterns exist between discharge and N sourcing and retention with respect to land cover and precipitation. Using data compiled from 78 catchments from across the world, we id...