Functional attributes of conifers expanding into temperate semi-arid grasslands modulate carbon and nitrogen fluxes in response to prescribed fire

Fire exclusion is a key factor driving conifer expansion into temperate semi-arid grasslands. However, it remains unclear how reintroducing fire affects the aboveground storage of carbon (C) and nitrogen (N) in the encroaching tree species and belowground in soils. To assess the impacts of fire reintroduction C and N pools and fluxes in areas of conifer expansion we targeted a region of the Northern Great Plains that has experienced extensive woody plant expansion (WPE) of two species: ponderosa pine (Pinus ponderosa) and juniper (Juniperus spp). We quantified tree mortality of both species to estimate the amount of dead biomass C and N produced by a recent prescribed fire, in addition to changes in soil C, pyrogenic C (PyC), and N concentrations across a woody-cover gradient using a before/after/control experimental design. Post-fire soil chemical analysis revealed a 2-year increase in mineral soil C, PyC and N, suggesting the return of fire led to the transfer of partially combusted p..., The data from this study was collected over multiple field seasons and includes soil chemistry, bole and foliar biomass chemistry for pinus ponderosa and juniperus scopulorum, individual ponderosa stem measurements and biophsyical data for field plot characterization. , , # Functional attributes of conifers expanding into temperate semi-arid grasslands modulate carbon and nitrogen fluxes in response to prescribed fire

[https://doi.org/10.5061/dryad.v9s4mw756](https://doi.org/10.5061/dryad.v9s4mw756)

## Description of the data and file structure

Data include

1. pre and post soil chemistry concentrations and area scaled pools (0-10 cm soil depth)
2. biophysical plot characteristics
3. individual pinus ponderosa stem measurements
4. needle leaf and bole chemistry for pinus ponderosa and juniperus scopulorum

All NA's indicate missing or unmeasured values

See associated manuscript for detailed information on collection, processing, and analysis.

### Files and variables

#### File: fire\_soil\_chemistry.csv

**Description:** Soil chemistry at a 0-10 cm soil depth pre and post fire treatment

##### Variables

* Plot: Plot identifer
* Label: month and day of sample collection
* Month: month of collection
* Year: year of collection
* Treatment: fire treatm...