Forage Selection Research Articles

Natural browsing repellent to protect Scots pine Pinus sylvestris from European moose Alces alces

A major problem within forestry is winter browsing on young Scots pine (Pinus sylvestris) by European moose (Alces alces). Moose are selective foragers and make foraging decisions on many scales, for example, they avoid trees with high levels of plant defensive compounds, which reduce digestibility. Bark extract from Norway spruce (Picea abies) is known to have high levels of such defensive compounds. The aim of this study was to evaluate the effects of Norway spruce bark extract as a repellent to European moose. Spruce bark was extracted in a conventional way with ethanol as the solvent, creating a solution that was applied to the apical leader of young pine trees in planted forests. In two field trials in northern Sweden (winter 2017–2018 and winter 2018–2019), the apical leader of young pine trees (height 1–2.5 m) were sprayed with bark extract from Norway spruce. A total of 5247 pine trees were included in the study. The field trials showed that spruce bark extract lowered the number of browsed apical leader of pine trees, and directed moose to browse less valuable lateral shoots, and neighboring trees. During the first field trial, apical leaders were treated every second meter along transects with a concentration of the spruce bark extract of 2.8% by dry weight. The level of browsed apical leaders changed from 15.1% to 6.8% of all apical leaders. During the second field trial, apical leaders were treated in circular plots, in which all main stems inside the circle were treated with a concentration of the spruce bark extract of 5.0% by dry weight. The level of browsed apical leaders changed from 19.5% to 4.7% of all apical leaders. Hence, results show that spruce bark extract (a non-toxic forest byproduct) can function as an efficient repellent. The bark extract can control browsing to a level that is considered acceptable – generally a maximum of 5% of all apical leaders browsed every year. This would result in approximately 7 out of 10 trees, in treated small scale areas, having unbrowsed apical leaders when the trees reach a height at which the apical leaders are safe from moose browsing.

Diet of a rare herbivore based on DNA metabarcoding of feces: Selection, seasonality, and survival.

In herbivores, survival and reproduction are influenced by quality and quantity of forage, and hence, diet and foraging behavior are the foundation of an herbivore's life history strategy. Given the importance of diet to most herbivores, it is imperative that we know the species of plants they prefer, especially for herbivorous species that are at risk for extinction. However, it is often difficult to identify the diet of small herbivores because: (a) They are difficult to observe, (b) collecting stomach contents requires sacrificing animals, and (c) microhistology requires accurately identifying taxa from partially digested plant fragments and likely overemphasizes less‐digestible taxa. The northern Idaho ground squirrel (Urocitellus brunneus) is federally threatened in the United States under the Endangered Species Act. We used DNA metabarcoding techniques to identify the diet of 188 squirrels at 11 study sites from fecal samples. We identified 42 families, 126 genera, and 120 species of plants in the squirrel's diet. Our use of three gene regions was beneficial because reliance on only one gene region (e.g., only trnL) would have caused us to miss >30% of the taxa in their diet. Northern Idaho ground squirrel diet differed between spring and summer, frequency of many plants in the diet differed from their frequency within their foraging areas (evidence of selective foraging), and several plant genera in their diet were associated with survival. Our results suggest that while these squirrels are generalists (they consume a wide variety of plant species), they are also selective and do not eat plants relative to availability. Consumption of particular genera such as Perideridia may be associated with higher overwinter survival.

Patch-scale selection patterns of grazing herbivores in the central basalt plains of Kruger National Park

Large herbivores form an essential component in the ecosystem, because of the impact that they have on their surrounding habitat. In this study, we aimed to evaluate some of the mechanisms behind how herbivores select forage at a patch scale. Thirty-six experimental plots were established and fitted with camera traps in Kruger National Park to test forage selectivity by grazers. Plots were manipulated by clearing with a brush cutter and the application of fertiliser. We used generalised linear models to detect trends in probability of occurrence by seven grazing herbivore species using camera trap data. Our results showed that season was a major determinant of species distribution, especially those that are not obligate grazers or feed exclusively in the 0.5 km to 2 km zone from water. We found that most selective feeding occurred in the late wet season when water would be more evenly distributed across the landscape and forage resources close to water would have had the chance to recover from depletion, as a result of dry season use. This has implications for the distribution of artificial water points across the landscape, because areas of reserve forage must be maintained to alleviate grazing pressure close to water.

Factors Contributing to the Springbok Population Decline in the Kalahari, Botswana

Nationwide aerial animal censuses of Botswana between 1992 and 2012, conducted by the Department of Wildlife and National Parks, have highlighted a 71% decline in the national springbok (Antidorcas marsupialis) population and a contraction of their range. The reasons for this decline remain unknown. We investigated possible drivers of this decline in the southern Kalahari of Botswana. We assessed springbok resource selection levels, movement behaviour and seasonal and spatial effects on the juvenile:adult female ratio. Springbok displayed high levels of forage and habitat selection. Their dependency on pan habitats renders their distribution predictable, which could expose them to high levels of predation and poaching. Springbok moved shorter daily distances during the hot dry and longer distances during wet seasons. High temperatures during the hot dry season could limit movement and prevent exploitation of spatially and temporally heterogeneous resources. We recorded a ratio of 0.37 juvenile:1 adult female in the wet season months followed by a ratio decline to 0.10:1 in the subsequent cold dry season, indicating a low recruitment rate that could be contributing to the springbok population decline. Environmental changes and anthropogenic disturbances, exacerbated by climate change, will likely exert a negative influence on selective foragers like springbok.

What do stable isotopes tell us about the trophic ecology of Thamnodynastes hypoconia (Serpentes: Dipsadidae) in southern Brazil?

Snakes are a useful model for ecological studies because they are gape-limited predators that may undergo ontogenetic changes in diet. We analyzed carbon and nitrogen stable isotope ratios to estimate percent contributions of different prey to snake biomass, trophic positions and isotopic niche width of juveniles and adults of the snake Thamnodynastes hypoconia. We also estimated the isotopic niche overlap between the two age categories. During eight intervals over a two-year period, we collected samples of whole blood and scales at a site in southern Brazil. Isotopic ratios of carbon and nitrogen did not differ between juveniles and adults for either tissue type, nor did mean trophic positions of juveniles and adults differ. The percent contribution of prey categories to snake biomass differed to a limited extent between the two years, with Hylidae being the most important anuran group assimilated during the first year and Leptodactylidae during the second year, for both ages. The isotopic niche occupied by adult snakes was slightly larger than that of juveniles when the analysis was based on data from whole blood samples, as expected because snakes are gape-limited. We found a reverse pattern when the analysis was based on scales, which may indicate that adult snakes have a smaller niche over the long term as they become selective foragers in certain prey. Isotopic overlap between juveniles and adults occurred during the two years, but it was bigger during the second year. We infer that, despite differences in gape size, juvenile and adult snakes in the study area exploit similar prey, with the degree of trophic similarity varying interannually.

Winter foraging of sympatric red deer and sika deer in northeast China: diet composition, forage selection, bite diameter and browse intensity

ABSTRACT Red deer (Cervus elaphus) and sika deer (C. nippon) are sympatric in certain regions in northeast China, and may have different strategies for obtaining food resources. We studied winter forage selection of sympatric red and sika deer based on their bite diameter and browse intensity in northeast China. The principal winter food items of red and sika deer were Euonymus spp. and Acer spp., and both deer showed strong selectivity for E. verrucosus, E. alatus and Populus davidiana (EI>0.85) in spite of their low availability. Red and sika deer exhibited varying bite diameters and browse intensity for different forage plant species between early and late winter. Overall, the interaction effect of season and deer species on bite diameter and browse intensity indicated that two sympatric deer used different foraging strategies to increase food intake. In late winter, sika deer may have tended to increase bite diameter to fulfill a relatively constant food intake and potential nutritional requirement, while red deer may have tended to increase browse intensity to maintain a higher forage intake. Moreover, the interaction effect of plant and deer species on bite diameter and browse intensity indicated that both deer species tend to change their bite diameter and browse intensity particularly on Euonymus spp. and Acer spp., while red and sika deer have a reversal interaction effect on coniferous browse. These patterns of forage selection in bite diameter and browse intensity of sympatric deer may reflect short-term foraging decisions of sympatric herbivores that share similar food resources.

Effect of sodium amendments on the home-field advantage of litter decomposition in a subtropical forest of China

Sodium (Na) can affect ecosystem function by altering soil fauna and microbial community composition and abundance. Sodium’s potential influences on plant-soil interactions, such as home-field advantage (HFA: enhanced decomposition in a home environment compared to an away environment), in relation to litter decomposition remains unclear. To fill this knowledge gap, we conducted a ten-month reciprocal litter transplant field experiment with Na amendments (0.005% and 0.5% water solution of NaCl) in both a subtropical broad-leaved forest dominated by Quercus variabilis (oak) and a coniferous artificial forest planted by Pinus massoniana (pine) in China. Litterbags with different mesh sizes were used to partition the impact of soil biota groups on the HFA. The results showed that 0.005% Na amendment facilitated litter decomposition as well as carbon (C) and nitrogen (N) mineralization by enhancing soil extracellular enzyme activity and soil faunal abundance. But 0.5% Na amendment inhibited litter decomposition in fine-mesh litterbags by decreasing microbial activity, and promoted litter decomposition in coarse-mesh litterbags by attracting more soil fauna. In the control plots, we observed a negative HFA in coarse-mesh litterbags (with most soil fauna and all soil microorganisms), and a positive HFA in fine-mesh litterbags (with complete exclusion of meso-and macrofauna). Whether the HFA was positive or negative (i.e. regardless of the direction of the HFA), Na amendments significantly decreased the magnitude of HFA by increasing the similarity of microbial community composition between the incubation fields (‘home’ vs. ‘away’) and decreasing selective foraging of soil fauna for different leaf litters. In sum, our results indicate that anthropogenic Na enrichment can decrease the effects of HFA through the modification of soil microbial and faunal communities, and thereby affect C sequestration and N cycling in subtropical forests.

Nutritional-Landscape Models Link Habitat Use to Condition of Mule Deer (Odocoileus hemionus)

In heterogeneous landscapes, large herbivores employ plastic behavioral strategies to buffer themselves against negative effects of environmental variation on fitness. Yet, the mechanisms by which individual responses to such variation scale up to influence population performance remain uncertain. Analyses of space-use behaviors exemplify this knowledge gap, because such behaviors are often assumed, but rarely demonstrated, to have direct fitness consequences. We combined fine-scale data on forage biomass and quality with movement data and measures of somatic energy reserves to determine whether variation in use (the quantity of resource units, e.g., pixels on a landscape, that receive some level of investment by an animal during a specific sampling period) or selection (use of a resource unit relative to its availability to the animal during the same sampling period) of the nutritional landscape predicted early winter body condition of mule deer (Odocoileus hemionus). At the population level, mule deer exhibited stronger selection for high forage biomass at the landscape scale than at the home-range scale, and during summer than during spring. Use of the nutritional landscape varied among individual deer and had important consequences for early winter condition (an important determinant of survival and reproduction in capital-breeding ungulates). Females that consistently used vegetation communities that provided high biomass of preferred forage plants throughout spring and summer entered winter in better condition than females that used those vegetation communities less frequently. In contrast, selection (i.e., use relative to availability) of the nutritional landscape by individual deer was not significantly related to early winter condition at either the landscape or home-range scales. Our results highlight the value of using mechanistic, nutritional approaches to understand the potential fitness consequences of individual variation in behavior. In addition, our study suggests that patterns of forage use by ungulates may sometimes correlate more strongly with fitness than patterns of forage selection, which are scale-dependent and more vulnerable to biases stemming from the need to accurately quantify availability.

Corrigendum to “Grazing behaviour, forage selection and diet composition of goats in a Mediterranean woody rangeland” [Small Ruminant Res. 145, 2016, 142–153

Corrigendum to “Grazing behaviour, forage selection and diet composition of goats in a Mediterranean woody rangeland” [Small Ruminant Res. 145, 2016, 142–153

Microhabitat variables explain patch switching by wintering Bewick’s swans through giving-up net energy intake rates

Microhabitat variables are determinants for animals to select forage patches and evaluate the cost/benefit tradeoffs of habitat switching. Optimal foragers would weigh habitat quality by giving-up net energy intake rate (GUN), which includes the energy intake rate and cost rate. The GUNs, energy intake rate, and cost rate can be influenced by variations in different microhabitat factors and interactive effects. In this study, we assessed the GUN patterns of wintering Bewick's swans and the effects of microhabitat factors on their foraging strategy in three different habitats: foxnut ponds, paddy fields, and shallow lake. The foraging behaviors and microhabitat variables of the swans were investigated during the winters of 2016-2018 and 2017/2018 at Huangpi and Shengjin Lakes in Anhui Province, southeastern China. The results showed that the percentage of disturbance time and the giving-up food density in shallow water had significant negative effects on GUNs. In contrast, water depth and the giving-up food density in deep water showed positive effects on GUNs. GUNs were significantly different among the three habitats. GUNs also decreased as winter progressed. Swans would decrease their GUNs under unfavorable foraging conditions such as more disturbances; however, GUNs would increase with water depth and food availability in patches with deep water. The swans demonstrated diverse GUN patterns in different foraging habitats, driven by the tradeoffs between energy intake rates and energy cost rates that were influenced by microhabitat variables. It implies that waterbirds exposed to decreasing GUNs may mitigate energy demand and environmental stress by switching foraging habitat while in subprime foraging habitat if alternative habitats that offered higher net rates of energy gain were available.

Out of scale out of place: Black rhino forage preference across the hierarchical organization of the savanna ecosystem

AbstractThe successful conservation plans of megaherbivores necessitate precisely characterizing their ecological needs in order to optimize reproduction rates and reintroduction plans. The black rhino (Diceros bicornis L.) is among the most endangered species of megaherbivores in Africa and its conservation relies on nature reserves that are bound and habitat‐restricted. Therefore, identifying the optimal amount of space this species needs and the factors driving its habitat use are crucial for establishing reserve priority plans. Knowing that forage selection is an important component linked to herbivore spatial distribution, we combined 5 years of sightings data with observations of rhinos' vegetation type and forage preferences to address their forage selection across multiple spatial scales. We found that black rhinos' spatial distribution was negatively associated with ecosystem productivity, but positively associated with specific vegetation types that contain highly preferred, chemically distinct, plant species. Black rhinos thus occupy their habitat across space and time through selective foraging on preferred plants.

State-dependent foraging by caribou with different nutritional requirements.

Foraging by animals is hypothesized to be state-dependent, that is, varying with physiological condition of individuals. State often is defined by energy reserves, but state also can reflect differences in nutritional requirements (e.g., for reproduction, lactation, growth, etc.). Testing hypotheses about state-dependent foraging in ungulates is difficult because fine-scale data needed to evaluate these hypotheses generally are lacking. To evaluate whether foraging by caribou (Rangifer tarandus) was state-dependent, we compared bite and intake rates, travel rates, dietary quality, forage selection, daily foraging time, and foraging strategies of caribou with three levels of nutritional requirements (lactating adults, nonlactating adults, subadults 1–2 years old). Only daily foraging times and daily nutrient intakes differed among nutritional classes of caribou. Lactating caribou foraged longer per day than nonlactating caribou—a difference that was greatest at the highest rates of intake, but which persisted even when intake was below requirements. Further, at sites where caribou achieved high rates of intake, caribou in each nutritional class continued foraging even after satisfying daily nutritional requirements, which was consistent with a foraging strategy to maximize energy intake. Foraging time by caribou was partially state-dependent, highlighting the importance of accounting for physiological state in studies of animal behavior. Fine-scale foraging behaviors may influence larger-scale behavioral strategies, with potential implications for conservation and management.

Choosy grazers: Influence of plant traits on forage selection by three cattle breeds

Abstract Forage selection by herbivores is a major driver of plant diversity in pasture vegetation. Yet, we know relatively little about how plant traits influence decisions of different herbivore species and breeds to select or avoid a certain plant species on semi‐natural pastures. We quantified the influence of the traits leaf N and P content, leaf dry matter content (LDMC), specific leaf area (SLA) and physical defence mechanisms on plant species selection for three cattle breeds: high‐yielding Angus × Holstein crossbreed, dual‐purpose Original Braunvieh and undemanding Highland Cattle. The cattle grazed a series of adjacent paddocks in different alpine pastures. Plant species selection was quantified by assessing the difference in biomass proportions of all plant species in 66 vegetation subplots per breed before and after grazing. Plant traits and indicator values were extracted from the TRY database. Data on 152 plant species were analysed using a local mixed‐effects model and a global multivariate hierarchical regression model. Plant traits had a clear impact on forage behaviour. Plants with high SLA, leaf N and P contents were significantly selected, whereas plants with high LDMC (e.g. woody plants) and defence mechanisms (e.g. thistles) were generally avoided. Species with high forage quality indicator values as defined by Briemle et al. (2002) were significantly preferred. More importantly, significant differences between forage behaviour of cattle breeds were detected. Selection by less‐productive Highland Cattle was much less influenced by plant traits than the selection by the two higher‐yielding breeds. Results indicate a clear impact of plant traits on forage selection and demonstrate breed‐specific influences. Highland Cattle (and possibly other robust breeds) graze less selectively and impose less selective exclusion on plants. Thereby, they likely influence plant species composition of pastures in a different way than high‐yielding breeds, thereby creating a distinct habitat. A free Plain Language Summary can be found within the Supporting Information of this article.

Dietary flavonoids and the altitudinal preference of wild giant pandas in Foping National Nature Reserve, China

Foraging selection of mammalian herbivores is thought to be not only governed by nutrients, but also influenced by plant secondary metabolites (PSMs) in their diets. Giant pandas (Ailuropoda melanoleuca) are well-known bamboo specialists and little is known about the effects of PSMs in bamboos on their foraging selection. Flavonoids are the most famous bioactive PSMs in bamboo leaves. Here, the spatiotemporal variation of total flavonoids (TF) and four typical carbon glycosides flavonoids (CGFs) (orientin, isoorientin, vitexin and isovitexin) in Bashania fargesii bamboo leaves in a vertical aspect and the association with altitudinal movement pattern of wild giant pandas were investigated. We found: (1) Both the TF and four CGFs in leaves of B. fargesii varied seasonally over elevations. Bamboo leaves in winter at higher elevation range were of the highest content. (2) Evident propensity of giant pandas for habitat selection exhibited in vertical direction. At the whole range of elevations B. fargesii distributed, giant pandas preferred to stay at 1600–1800 m. (3) The altitudinal preference of giant pandas and flavonoids in leaves of B. fargesii had significant positive correlations. The bamboo flavonoids at higher-elevation sites which were preferred by giant pandas were significantly higher than in lower-elevation area. (4) Validation in captive giant pandas showed those bamboo leaves unused in wild were of lower flavonoids especially the (iso)orientin compared to higher-elevation, which showed no differences with those unselected leaves in captivity. Our results indicate that the dietary flavonoids may be one of the driving factors shaping the altitudinal preference and diet selection of giant pandas which may be of significant physiological importance such as being playing key roles in the reproduction of such a dietary specialized species.

Species of forages utilized by farmers producing halal goats in Bangsamoro Autonomous Region in Muslim Mindanao (BARMM), Philippines

Abstract. Navarra GA, Salvaña FRP, Sepelagio EG, Sanchez CB, Besana CM, Manceras LJS, Bra SG. 2019. Species of forages utilized by farmers producing halal goats in Bangsamoro Autonomous Region in Muslim Mindanao (BARMM), Philippines. Asian J Ethnobiol 2: 1-7. Local production of small ruminants necessitates forage assessment considering the fact that animals are typically fed with locally available plant species. This study was carried out to determine the species of plants used as forage by raisers producing halal goats in BARMM (Bangsamoro Autonomous Region in Muslim Mindanao). Personal interview with the respondents producing halal goats was conducted and a questionnaire was used to determine species of forages. A total of eight municipalities were included in the survey, seven of which were from Maguindanao and one was from Lanao del Sur. Purposive sampling was used in the survey. A total of 47 respondents was interviewed based on the criteria: (i) a believer of Islam (ii) with 5 to 24 breeder does; and (iii) willingness of the farm owner to participate in the survey. All respondents fall to these criteria were interviewed. All respondents used forage species including paragrass (Brachiaria mutica), carabao grass (Paspalum conjugatum), ipil-ipil (Leucaena leucocephala) and kakawate (Gliricidia sepium) in all sampling sites. Other species included malunggay (Moringa oleifera), banana (Musa balbisiana), stylo (Stylosanthes humilis), centrosema (Centrosema pubescens), langka (Artocarpus heterophyllus), pinto peanut (Arachis pintoi), napier (Pennisetum purpureum), barnyard grass (Echinochloa sp.), Guinea grass (Panicum maximum), indigofera (Indigofera tinctoria), calliandra (Calliandra calothrysus), katurai (Sesbania grandiflora) and rensonii (Desmodium rensonii). Only eleven percent (11%) of the respondents utilized improved and domesticated species of forages. Improved and domesticated forage species are plants commonly cultivated forage for livestock production. Some species of plants present in open vegetated areas like Erigeron canadensis, Sphagneticola trilobata, Ageratum conyzoides and Urena lobata were also consumed by goats according to the respondents. There were also plant-related toxicosis observed by the respondents caused by C. pubescens and Urena lobata. Most of the respondents in BARMM are not utilizing improved and domesticated species of forages and rely on locally available forages present in rangeland. Most of them have limited knowledge of the nutritional requirements of goats. There is a need to enhance the understanding of farmers on the importance of proper forage selection and combination.

Poaching impedes the selection of optimal post-fire forage in three large grazing herbivores

Optimal foraging theory provides a powerful quantitative framework to reveal how foraging constraints and options define the interplay between forager and resource distributions. Although illegal hunting threatens wildlife worldwide, few studies have assessed the impact of poaching on the ability of animals to optimise their use of resources. We assessed how the risk of poaching hinders the ability of common reedbuck (Redunca arundinum), red hartebeest (Alcelaphus buselaphus), and plains zebra (Equus quagga) to maximise their daily intake of digestible energy in a complex mosaic of post-fire vegetation, in a small fenced nature reserve. Optimality models predict that all species can maximise their intake of digestible energy by feeding in young post-fire patches (29–37 days). We show that for all species, probability of finding and selectively using such high-value vegetation patches was higher at greater distance from points where poachers were likely to enter the reserve. For reedbuck, optimal patches were used only if they were >3.4 km from poacher entry-points. Red hartebeest became more likely to occur in optimal vegetation patches as the distance to likely poacher entry points increased. Only zebra maximized their daily intake of digestible energy regardless of the distance to poachers, but still selected areas where poaching was less likely. This study demonstrates how spatial patterns in poacher activities and post-fire vegetation interact to shape herbivore distribution. Understanding how herbivores track and use this post fire green-up of vegetation is important for protected area managers to understand the trade-offs that herbivores make when foraging.

Assessment of vegetation aptitude to accomodate organic beekeeping

The aptitude offered by land vegetation to accommodate organic beekeeping was assessed in the Santuario Apicola Paz de Aculeo, located in the Metropolitan Region of Chile. A multicriteria analysis methodology combining geomatics and remote sensing was designed. For this purpose, critical vegetation variables for forage selection by the bee populations were valued on the main vegetation units cadastrated for the study area. Thereafter, they were subject to a lineal combination that hypothesized several weighting scenarios. The afore-mentioned enabled to classify the units according to their aptitude to accommodate the beekeeping, which were further characterized according to their vegetation vigor throughout the phenological cycle; derived from NDVI (normalized difference vegetation index) composites, as well as to their topographic variability; derived from a DEM (digital elevation model). The results show that no matter the scenario supposed, the vegetation units of the study area can be divided into five aptitude classes, with those embracing the highest aptitude (1 and 2) as the most prevailing; being distributed at variable altitudes of generally southwest aspect. Although the NVDI composites yielded differences between classes, those were small and non-significant, as a variance analysis pointed out. This study seeks to approximate the management and planning of the beekeeping productive system of local scale to the geotechnologies usage. Further efforts could apply a similar methodology on more complex and heterogeneous vegetation areas with the aim of proving its versatility.

Forage Production and Selection for Vigor in Meadow and Hybrid Bromegrass in the Northern Great Plains

Meadow bromegrass (Bromus riparius Rehmann) is an important forage crop in Canada and the Intermountain West, but it has not been extensively evaluated in the northern Great Plains (NGP). Our objectives were to 1) evaluate meadow, smooth, and hybrid bromegrasses for forage production under intensive management in eastern South Dakota, and 2) evaluate the effect of selection for vigor in multiple environments on forage production of meadow bromegrass. Thirteen populations (7 meadow bromegrass, 5 hybrid bromegrass, and 1 smooth bromegrass) were evaluated for 4 yrs (2005-2007, 2009) at Brookings, SD. Biomass at anthesis was greater for smooth (6.75 Mg ha-1) than for meadow or hybrid brome (5.4 Mg ha-1) in 2005, but production at anthesis during 2006 and 2007 was similar for meadow and smooth bromegrass. Regrowth harvested during July and October 2005 and November 2006 was greater for meadow than smooth or hybrid bromegrass. Forage production at anthesis in 2009, after rest (i.e., no cutting) and fertilization in 2008, was 4.2 Mg ha-1 for meadow bromegrass compared with 3.3 Mg ha-1 and 2.6 Mg ha-1 for hybrid and smooth bromegrass, respectively. Smooth and hybrid bromegrasses had more leaves·tiller-1 than meadow bromegrass. After 6 yrs, meadow bromegrass had higher tiller density and greater potential for tolerating multiple harvests during a growing season than did smooth or hybrid bromegrass. Selection for vigor in multiple environments in North America resulted in experimental populations of meadow bromegrass with superior forage yield compared with ‘Fleet’ on marginal crop land in the northern Great Plains.

Deer‐mediated ecosystem service versus disservice depends on forest management intensity

Abstract As global terrestrial biodiversity declines via land‐use change, society has placed increasing value on non‐commercial species as providers of ecosystem services. Yet, many deer species and non‐crop plants are perceived negatively when they decrease crop productivity, leading to reduced economic gains and human‐wildlife conflict. We hypothesized that deer provide an ecosystem service in forest plantations by controlling competition and promoting crop‐tree growth, although the effects of herbivory may depend on forest management intensity. If management negatively affects foraging habitat at local and landscape scales, then we expected browsing to shift to less nutritious crop trees. To test these hypotheses, we established a 5‐year experiment that manipulated early forest management intensity via herbicide treatments and access of two deer species to vegetation via exclosures. Contrary to our hypothesis, deer provided an ecosystem service at high management intensities and a disservice occurred with low‐intensity management. Crop‐tree growth and survival was greatest when herbivory and herbicides suppressed broadleaf regeneration. In contrast, crop‐tree growth was lowest when broadleaf vegetation was retained and crop trees were subject to both browse damage and competition. We found a positive, yet variable, association between deer detections and stand – and landscape‐scale broadleaf habitat, and despite initial reductions in forage, herbivory pressure was similar among management intensities. When broadleaf vegetation was suppressed by herbicides and herbivory, selection of herbaceous forage by deer intensified, likely aiding in the service. Overall, our findings indicate that the effects of vegetation management for promoting timber production are highly dependent on the presence of large herbivores. Synthesis and applications. Although deer are thought to reduce crop productivity in many systems, we found that herbivory switched from reducing crop‐tree growth where non‐crop vegetation was retained, to promoting crop‐tree growth when both herbivory and herbicides suppressed competing vegetation. However, the provision of this ecosystem service is likely contingent on the amount of forage available in the landscape and subsequent foraging pressure. We conclude that nature's capacity to provide ecosystem services depends on the intensity of management at local and landscape scales.

Through the taste buds of a large herbivore: foodscape modeling contributes to an understanding of forage selection processes

How large herbivores track resource quantity and quality through time has formed the core of an abundance of literature on migratory populations in recent decades. Yet, relating foraging processes and habitat selection patterns in resident populations, where spatial heterogeneity of food resources is fine‐grained and/or where the portion of edible plants (i.e. the foodscape) is low, is challenging. We addressed this issue in a mountain population of chamois Rupicapra rupicapra, an intermediate feeder, whose individuals do not migrate. We relied on a rare combination of data on habitat use of 50 GPS‐collared females and data on the quantity (biomass) and quality (phenology) of edible resources in their landscape, derived from field sampling of vegetation, remote sensing and diet (DNA barcoding). The foodscape of the chamois was composed of a low proportion of the available biomass (<18%), including relatively high‐quality plants, with low spatial covariation between plant phenology and biomass. Chamois avoided areas with a low edible biomass (where the intake rate may be too low) and focused on areas with plants at approximately the flowering stage, whatever the average plant phenological stage available. Due to this constant preference for flowering plants, home range selection ratios therefore shifted during the summer from a selection of more advanced plants in June to their avoidance in August. When the phenology scores of all plants available, rather than edible plants only, were considered, areas with relatively more advanced plants were selected all summer long. This exemplifies that, when traits from edible plants are different from those of all plants available, it is crucial to consider the actual foodscape to decipher forage and habitat selection processes. By integrating species‐specific dimensions of resources in habitat selection studies, we believe understanding of the foraging processes will be improved.