Data used for analysis in publication

Download the Excel file and read worksheet 'Field Descriptions'

Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that intensive forest management and large herbivores have compounding effects on early-seral plant communities and plantation establishment (i.e., tree survival and growth), and the degree of such effects is dependent on the intensity of management practices. We established 225 m2 wild ungulate (deer and elk) exclosures nested within a manipulated gradient of management intensity (no-spray Control, Light herbicide, Moderate herbicide and Intensive herbicide treatments), replicated at the scale of whole harvest units (10-19 ha). Herbivory and herbicide applications interacted to drive vegetation structure, composition and crop-tree establishment, with herbivory effects most evident at intermediate herbicide treatments. Control stands were too forage-rich and Intensive stands too forage-poor to be substantially affected by herbivory. However, with Moderate herbicide treatment – which approximates treatments applied to > 2.5 million hectares in Pacific Northwest U.S.A. – foraging by deer and elk exacerbated the effect of the herbicides, resulting in simplified, low-cover plant communities resembling the Intensive herbicide treatment. In the Light herbicide treatment, herbivory suppressed shrub growth following herbicide treatment, improving planted conifer seedling survival, likely via competitive release from shrubs. Minor reductions in management intensity from the Moderate to Light herbicide treatments therefore facilitated the capacity of wild ungulates to benefit seedling survival – which constitutes early evidence of an ecosystem service. However, this ‘service’ may be to the detriment of native early-seral plant communities. These results demonstrate that by changing community composition and vegetation structure, intensive forest management alters foraging selectivity and subsequent plant-herbivore interactions; such shifts in early-seral communities are likely to influence understory plant communities and tree growth in later stages of forest development.

Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that intensive forest management and large herbivores have compounding effects on early-seral plant communities and plantation establishment (i.e., tree survival and growth), and the degree of such effects is dependent on the intensity of management practices. We established 225 m2 wild ungulate (deer and elk) exclosures nested within a manipulated gradient of management intensity (no-spray Control, Light herbicide, Moderate herbicide and Intensive herbicide treatments), replicated at the scale of whole harvest units (10-19 ha). Herbivory and herbicide applications interacted to drive vegetation structure, composition and crop-tree establishment, with herbivory effects most evident at intermediate herbicide treatments. Control stands were too forage-rich and Intensive stands too forage-poor to be substantially affected by herbivory. However, with Moderate herbicide treatment – which approximates treatments applied to > 2.5 million hectares in Pacific Northwest U.S.A. – foraging by deer and elk exacerbated the effect of the herbicides, resulting in simplified, low-cover plant communities resembling the Intensive herbicide treatment. In the Light herbicide treatment, herbivory suppressed shrub growth following herbicide treatment, improving planted conifer seedling survival, likely via competitive release from shrubs. Minor reductions in management intensity from the Moderate to Light herbicide treatments therefore facilitated the capacity of wild ungulates to benefit seedling survival – which constitutes early evidence of an ecosystem service. However, this ‘service’ may be to the detriment of native early-seral plant communities. These results demonstrate that by changing community composition and vegetation structure, intensive forest management alters foraging selectivity and subsequent plant-herbivore interactions; such shifts in early-seral communities are likely to influence understory plant communities and tree growth in later stages of forest development.

,This package contains perennial vegetation cover data measured using the line-intercept method from plots with various levels of herbivore exclusion on Jornada Experimental Range (JER) and Chihuahuan Desert Rangeland Research Center (CDRRC) lands. Study sites were established in 1995; one in black grama grassland and the other in creosotebush shrubland to compare the impact of herbivores on ecosystem processes between these vegetation types. Parallel studies were established at the Sevilleta LTER site (New Mexico, USA) and Mapimi Biosphere Reserve (Durango, Mexico). Each study site is 1 km by 0.5 km in area. Four replicate experimental blocks were randomly located at the grassland study site to measure vegetation responses using exclusion treatments including a) all mammalian herbivores, including cattle, lagomorphs, and rodents, b) lagomorphs and cattle only, c) cattle only, and d) control accessible to all herbivores. Because grazing cattle are excluded from the entire creosote site, only three replicate experimental blocks were randomly located there including a) all mammalian herbivores, including lagomorphs, and rodents, b) lagomorphs only, and c) control accessible to all herbivores. Thirty-six sampling points were positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot. A permanent one-meter by one-meter vegetation measurement quadrat is located at each of the 36 points. The vegetation line-intercept measurements in this data package were made in fall 1995 and fall 2005 to coincide with low-level aerial photography campaigns. Three 29-meter lines were measured along three out of six rows of permanent vegetation quadrats. Intercept locations for live, perennial plant cover and bare ground were measured along each line at 10cm resolution, which is comparable to the resolution of the aerial photos. Plants were identified to species level where possible. The resulting cover data can used to ground-truth cover estimates from aerial photography or for comparison to annual measures of vegetation from 1 x 1 meter permanent vegetation quadrats. This study is complete.,,

,This data package contains vegetation cover from plots with various levels of herbivore exclusion on the Jornada Experimental Range (JER) and Chihuahuan Desert Rangeland Research Center (CDRRC) in Dona Ana County, southern New Mexico, USA. Study sites were established in 1995; one in black grama grassland and the other in creosotebush shrubland to compare the impact of herbivores on ecosystem processes between these vegetation types. Parallel studies were established at the Sevilleta LTER site (New Mexico, USA) and Mapimi Biosphere Reserve (Durango, Mexico). Each study site is 1 km by 0.5 km in area. Four replicate experimental blocks were randomly located at the grassland study site to measure vegetation responses using exclusion treatments including a) all mammalian herbivores, including cattle, lagomorphs, and rodents, b) lagomorphs and cattle only, c) cattle only, and d) control accessible to all herbivores. Because grazing cattle are excluded from the entire creosote site, only three replicate experimental blocks were randomly located there including a) all mammalian herbivores, including lagomorphs, and rodents, b) lagomorphs only, and c) control accessible to all herbivores. Thirty-six sampling points were positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot. A permanent one-meter by one-meter vegetation measurement quadrat is located at each of the 36 points. At each quadrat, percent cover by individual plant species is measured. Other measurements include height (cm) of each species in the quadrat, and plant condition (living or dead). Data were collected in the spring and fall of every year from 1995 to 2005. After 2005, sampling frequency changed to every 5 years in the fall. This study is ongoing.,,

Eighty-one monitoring plots within the Minidoka National Wildlife refuge on the Snake River Plain in south-central Idaho were surveyed in July-August from 2020 to 2023 to evaluate the effects of herbicides on the vegetation-community across areas that varied in both burn history and background cheatgrass abundance. Surveys consisted of line-point intercept measurements along two 6m or 50m transects with 100 points of observation per line. In spring of 2023 "escaped" cheatgrass individuals were counted in each 6x6m herbicide-treated plot.

Eighty-one monitoring plots within the Minidoka National Wildlife refuge on the Snake River Plain in south-central Idaho were surveyed in July-August from 2020 to 2023 to evaluate the effects of herbicides on the vegetation-community across areas that varied in both burn history and background cheatgrass abundance. Surveys consisted of line-point intercept measurements along two 6m or 50m transects with 100 points of observation per line. In spring of 2023 "escaped" cheatgrass individuals were counted in each 6x6m herbicide-treated plot.

,Zestawienie pozyskanego leśnego materiału rozmnożeniowego wg gatunków w poszczególnych latach,