an evaluation of early spring turn-out on · shrubs such as saskatoon were also heavily browsed and...

AN EVALUATION OF EARLY SPRING TURN-OUT ON BRITISH COLUMBIA GRASSLANDS

RANGE EFFECTIVENESS EVALUATIONS 2006

Doug Fraser, P.Ag. Francis Njenga, P.Ag Rick Tucker, P.Ag Range Practices Officer Range Ecology Officer Range Ecology Specialist

Range Branch Ministry of Forests and Range September 30, 2007

ii

Abstract During the spring of 2006, Range Branch and District Range staff evaluated 42 representative spring turn-out pastures ranging from the south Okanagan to the Peace River. We selected these areas because of their long histories of cattle grazing and planned grazing systems. We focused on true grassland and grassland-shrub communities.

Soil compaction was severe enough to restrict plant root growth and water infiltration on almost all sites, regardless of soil texture. Fine textured soils (clays and silts) were the most severely compacted. Range reference areas (RRAs) that had been protected from grazing for twelve to sixteen years were in a recovery mode though they were still slightly compacted at the 10 cm depth.

We found that many turn-out pastures either lacked or had an altered biological soil crust (cryptogam) layer. Biological soil crusts (BSCs) should not be confused with physical soil crusts that form as a result of raindrop impacts on bare soils. BSCs, including lichens, are important in healthy functioning mineral and water cycles. An absent or altered cryptogam layer means that the carbon and nitrogen cycles are not functioning well. An intact BSC layer will provide a uniform distribution of nitrogen, which is released and available for early spring grass growth. Native legumes are scattered and deep rooted and cannot provide the same distribution or timely release of nitrogen as BSCs. This is probably why many interior rangelands are nitrogen poor. The role of BSCs warrants further study.

Forage volumes (combined new growth and old residue) ranged from a low of 188 kg/ha (5.3 ha/AUM) to a high of 1100 kg/ha (0.4 ha/AUM) on a domestic seeding. In all cases, residual cover from the previous year comprised the majority of dry matter; without it, cattle would not have enough volume, even when new growth had reached a height of 15 cm (6”). Residual cover also insulates new tillers from temperature extremes and helps in the capture and storage of moisture.

In the Peace Forest District, wild ungulates and cattle were in direct competition for forage on some spring turn-out pastures. Deer had grazed the new grass growth to below 2 cm prior to the arrival of livestock. Shrubs such as saskatoon were also heavily browsed and under 15 cm in height. Heavy use by wild ungulates in these pastures contributed to early seral conditions, bare soil, erosion and low grass volumes. This heavy use also means that shrubs are low stature and unavailable as browse in winter when there is snow cover.

The healthiest and highest producing native turn-out pastures had planned rest as part of their grazing rotation.

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Table of Contents Abstract ............................................................................................................................................... i Abstract .............................................................................................................................................. ii Table of Contents.............................................................................................................................. iii List of Figures ................................................................................................................................... iv List of Tables ......................................................................................................................................v Background.........................................................................................................................................1 What is range readiness ......................................................................................................................1

Why consider range readiness ........................................................................................................1 Plants and soils........................................................................................................................... 1 The grazing animal .................................................................................................................... 1

Project Overview ............................................................................................................................1 Objectives .......................................................................................................................................2

Methodology.......................................................................................................................................3 i). Functionality assessments............................................................................................. 4 ii). Range level 1 inspection form ...................................................................................... 4 iii). Soils information........................................................................................................... 4 iv). Forage production ......................................................................................................... 5 v). Stubble height measurements ....................................................................................... 5 vi). Browse utilization and form class................................................................................. 6 vii). Current and potential plant community descriptions .................................................... 6 viii). Invasive plant species ................................................................................................... 6 ix). Notes ............................................................................................................................. 6 x). Photographs................................................................................................................... 6

Results.................................................................................................................................................7 Okanagan-Shuswap Forest District (Penticton zone) .....................................................................7 Kamloops Forest District ................................................................................................................9 Cascades Forest District................................................................................................................12 Central Cariboo Forest District.....................................................................................................13 Peace Forest District .....................................................................................................................17

Concerns ...........................................................................................................................................19 Recommendations.............................................................................................................................21 Appendix 1. Excerpt from “The Range Resources Assessments Procedure ....................................22 Appendix 2. Uplands Function Checklist .........................................................................................23 Appendix 3. Description of Plant Communities and Habitats..........................................................24 Appendix 4. Plant Community Description Form ............................................................................25 Appendix 5. Staff participating in the evaluation .............................................................................26 Appendix 6. Scientific name, four letter code, and common names of plant species. .....................27

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List of Figures

Figure 1. The ecosystem processes functioning in rangelands. ......................................................... 2

Figure 2. The potential impacts of grazing management on soils, plant species composition, energy and hydrology. ............................................................................................................................. 3

Figure 3. Creating a saturated paste in preparation for measuring electrical conductivity (EC)....... 5

Figure 4. Measuring soil compaction with a hand-held force gauge................................................. 5

Figure 5. Clipping and sorting forage production in a 0.25 m² circular plot. .................................... 5

Figure 6. Measuring new growth by leaf development and tiller length. .......................................... 6

Figure 7. Early-seral plant communities, with low residual cover and bare soil............................... 7

Figure 8. Representative photographs from the Kamloops Forest District ..................................... 10

Figure 9. Healthy lower elevation bluebunch wheatgrass with a healthy cryptogam layer ............ 15

Figure 10. Early-seral, HR mid-elevation grasslands with reduced cryptogam layer. .................... 15

Figure 11. Mid-upper elevation grassland opening in a Douglas-fir forest. .................................... 16

Figure 12. Soil erosion, poor residual cover and soil compaction were common. .......................... 18

Figure 13. Heavy spring use by wildlife was common on south exposures. ................................... 19

Figure 14. Biological soil crusts (cryptogams) perform an important function in grassland plant communities............................................................................................................................... 20

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List of Tables

Table 1. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Okanagan-Shuswap Forest District.............................................................................................. 7

Table 2. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Okanagan-Shuswap Forest District.............................................................................................. 8

Table 3. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Kamloops Forest District. ............................................................................................................ 9

Table 4. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Kamloops Forest District. .......................................................................................................... 11

Table 5. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Cascades Forest District............................................................................................................. 12

Table 6. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Cascades Forest District............................................................................................................. 12

Table 7. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Central Cariboo Forest District.................................................................................................. 13

Table 8. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Central Cariboo Forest District.................................................................................................. 14

Table 9. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Peace Forest District. ................................................................................................................. 17

Table 10. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Peace Forest District. ................................................................................................................. 18

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Background What is range readiness The Society for Range Management defines range readiness as “a defined stage of plant growth at which grazing may begin under a specific management plan without permanent damage to vegetation or soil.”

For the past 20 years, some managers have questioned the concept of range readiness after experimenting with refined grazing systems. Some range managers maintain that planned grazing systems with rotations and periodic rest have made range readiness obsolete. Others maintain that the time of grazing is irrelevant; instead, it is the severity of grazing (how much leaf is removed) and the time interval before regrazing that is important.

Both arguments have some merit. However, there are two elements of range readiness that are often overlooked. Firstly, the soil must be dry enough so that plants are not easily uprooted and trampling and compaction are minimised. Secondly, there must be an adequate volume and quality of forage available to the grazing animal. From a strictly animal nutrition and production perspective, early grazing may be questionable.

Range readiness is optional in range use plans and range stewardship plans under the Forest and Range Practices Act (FRPA), and is required only where stipulated by the Minister of Forests and Range.

Why consider range readiness Plants and soils Grazing at the wrong time damages individual plants, the plant community, and soils. Severe or frequent grazing may eventually kill a plant by drawing down its carbohydrate reserves, reducing its vigour, and weakening its root system. Increaser or invader plant species, which due to their growth form, physiology or lower palatability to livestock are resistant to grazing and trampling, often replace the dead plants.

Soil is the basic resource that determines the capability of a site to support vegetation and grazing animals. The potential of the site is reduced and forage production decreases as a result of soil damage or loss through erosion.

The grazing animal Cattle are most efficient grazers when plants being grazed are about 15 cm in height. An animal on poor condition range with short and widely-spaced plants will take more bites, travel farther, and graze longer to meet daily requirements. If forage is only 1 cm high, daily intake will be reduced by 80% and animal production will decline.

Project Overview Range Branch of the Ministry of Forests and Range is responsible for developing legislation, guidebooks, policies and best practices governing livestock grazing on Crown rangelands. The Branch is also responsible for evaluating how effective the legislation, policies, and practices are in protecting Crown rangelands. Branch and District range staff evaluated rangeland health and plant community seral condition on grasslands as follows: those with early spring turn-out (March to mid-May); those grazed in both spring and fall each year; and those grazed by calendar date.

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Rangeland health1 is the degree to which the soils and ecological processes of rangeland systems are sustained (Figure 1.2).

MINERAL CYCLE Atmosphere:Carbon & Nitrogen

RUNOFF LOSSWATER & NUTRIENTS

LEAF FALL DUNG

URINEGood penetration andrapid recycling required

Simple Communities• few different species• fluctuations in numbers high• instability high

Complex Communities• many different species• fluctuations in numbers low• stability high

WATER CYCLEPenetration+Aeration=Effective Precipitation

RAINFALL SURFACEEVAPORATION

TRANSPIRATION

RUNOFF

WATER TABLE

BRITTLENESS

Brittle Non-Brittle

Energy lost as heatand no longer usablefor living organisms

Plant organisms on land and in water

Further predators,including humans

Fish, mammals, birds, insects, humans

Decay

ScavengersDecay

Predators, including humans

BASIC ENERGY PYRAMID

Figure 1. The ecosystem processes functioning in rangelands.

Objectives The objectives of this assessment were to:

• evaluate spring forage by height, volume and quality; and, • evaluate the health and functionality of rangelands using standard methodology3.

Livestock grazing affects plant species composition, forage production, soils, hydrology, and indirectly, other animal species. Figure 24 is a diagrammatic representation of the effects of proper and improper grazing management.

1 Busbee, F.E. 1994. Rangeland Health. New Methods to classify, inventory and monitor rangelands, NRC

Washington, DC. 2 (Source: Upland and Riparian Remedial Measures Primer. Range Branch, MoFR) 3 Fraser, D. A. 2006. Range Resources Assessments Procedures. Ministry of Forests and Range. 4 Source: National Range and Pasture Handbook, Figure 7-7. NRCS, USDA 2006.

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Figure 2. The potential impacts of grazing management on soils, plant species composition, energy and hydrology.

Methodology We (see Appendix 5 for participating staff) evaluated areas under Range Act agreements in Cascades, Central Cariboo, Kamloops, Okanagan-Shuswap and Peace Forest Districts. We selected these districts because of their long histories of cattle grazing and planned grazing systems. We focused on true grassland and grassland shrub communities of the following types:

• Idaho fescue/bluebunch wheatgrass; • Bluebunch/big sagebrush; • Rough fescue/bluebunch wheatgrass; • Bluebunch wheatgrass/porcupine grass; and, • Mixed grass prairie (northern wheatgrass/needlegrass/shrub).

4

We visited representative early spring turn-out pastures prior to livestock turn-out or in some cases when livestock were already on site. At each site, preferably in key areas, we completed a rangeland health assessment form, a rangeland inspection form and collected soils information and forage production. At sites with no key areas, we chose a location that represented the pasture unit. Where possible we compared grazed sites to ungrazed benchmarks (range reference areas)

The Information was recorded in ArcPad™5 on a Trimble Recon™ handheld computer. Global Positioning System (GPS) locations (in Universal Transverse Mercator (UTM) and Albers projections) were recorded for each site. Blank assessment checklists are in Appendix 1. At each site, we recorded the following attributes and measurements:

i). Functionality assessments Site functionality was assessed using Ministry range assessment procedures6. Assessments were based on observations of the area attributes as listed in the checklists. For example, if an area had all or mostly all positive answers to the attributes on the checklist, it was deemed healthy, and at Proper Functioning Condition (PFC). If an area had few or no positive attributes on the checklist, it was deemed non-functional or at risk. A rating of slightly at risk (61-79%) may trigger some follow-up action such as more detailed monitoring or a change in management; or if an upward trend emerges, may verify that the management prescription is working. Riparian and upland systems rated as moderately at risk (41-60%) to non-functional (<20%) and having a downward or static trend will require remedial measures.

ii). Range level 1 inspection form7 We determined plant species composition, leaf development stage and leaf lengths of key grasses, and phenology of forbs and shrubs.

iii). Soils information We measured soil temperature, electrical conductivity (EC), and soil strength at three levels (surface, 1 cm and 10 cm depths). We used a digital handheld force gauge8 with a 4 mm 30º tapered cone for measuring soil strength (compaction) at the surface and at 1 cm and 10 cm depths, and a WET Type 2 Sensor9 to measure EC and soil temperature. Salinity is categorized as follows:

Descriptive categories

Range in milliSiemens/per meter (mS/m)

Non-saline 0 to 20

Slightly saline 20 to 40

Moderately saline 40 to 80

Strongly saline 80 to 160

Extremely saline > 160

5 Mention of trade names does not imply endorsement by the Ministry of Forests and Range. 6 Fraser, D. A. 2006. Range Resources Assessments Procedures. Ministry of Forests and Range. Ministry of Forests. 7 Ministry of Forests and Range. 2006. A methodology for monitoring Crown range. 8 Transducer Techniques HFG Series Force Gauge. Mention of trade names does not imply endorsement by the Ministry of Forests and Range. 9 Delta-T Devices Ltd. Mention of trade names does not imply endorsement by the Ministry of Forests and Range.

5

Figure 3. Creating a saturated paste in preparation for measuring electrical conductivity (EC).

Figure 4. Measuring soil compaction with a hand-held force gauge.

iv). Forage production At each site, we clipped four circular (0.25 m²) plots to ground level and sorted graminoids into green and dry material. The clippings were oven dried at 50 ºC for 24 hours and weighed to estimate forage production as dry matter.

Figure 5. Clipping and sorting forage production in a 0.25 m² circular plot.

v). Stubble height measurements Stubble height or new growth was estimated assuming that under normal grazed conditions, there will be a patchy pattern of use with some plants grazed completely, some grazed moderately and some not grazed at all.

6

Figure 6. Measuring new growth by leaf development and tiller length.

vi). Browse utilization and form class At each site, a description of the major shrub species, an estimate of the current browse use and the browse form class (an indication of past use) was recorded.

vii). Current and potential plant community descriptions At each site, the current and potential plant community was described (layers, dominant and co-dominant species) and the current seral stage was estimated. Sites were compared to ungrazed benchmarks (range reference areas) where possible.

Seral stage is defined as the plant community’s similarity to the potential natural community (PNC)-climax, which is considered the site’s potential. Seral stage categories have the following ranges:

viii). Invasive plant species Where found, invasive plants were listed, and the size and distribution of the infestation recorded.

ix). Notes We also recorded plant use and distribution patterns, localized trampling and over-use, recreational use, and aesthetics.

x). Photographs We took digital photographs at each site.

Seral stage Early-seral Mid-seral Late-seral PNC-Climax % similarity to PNC-Climax 0-25% 25-50% 50-75% >75% climax

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Results Okanagan-Shuswap Forest District (Penticton zone) The Penticton zone, now and historically, has the earliest spring turn-out of any area in the province. Sites were visited on April 12, just prior to the normal spring turn-out. Downy brome was prevalent on two sites.

Figure 7. Early-seral plant communities, with low residual cover and bare soil. Table 1. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Okanagan-Shuswap Forest District.

Date 2006 Site Seral

stage Functional condition

Soil texture

Root 10restricting threshold g/cm³

Soil strength11 g/cm³

Soil EC (mS/m) slurry12

Soil temp.(0C)

Top 1.88 38 18.7 1 cm 1.15 April 12 Chopaka

Exclosure Early SR/ Sandy loam 1.75

10 cm 2.15 Top 4.3 37 11.5 1 cm 1.67 April 12 Nighthawk Early† NF Sandy

loam 1.75 10 cm 4.36 Top 1.81 25 15.8 1 cm 0.82 April 12 South

Woodyard Early† HR Sandy 1.80 10 cm 3.26 Top 1.57 35 14.4 1 cm 1.42 April 12 Dump Early SR Sandy

loam 1.75 10 cm 3.25

† Old crested wheatgrass seeding

10 USDA Natural Resource Conservation Service. 2001. Rangeland soil quality information Sheet – Compaction. Rangeland sheet 4. 11 For 4 mm 30o tapered cone measured at surface, at 1 cm and 10 cm depths. 12 Water was added to prepare a saturated paste (slurry) of 40% moisture.

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Table 2. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Okanagan-Shuswap Forest District.

Readiness Production13 (kg/ha) Carrying capacity.(ha/AUM)

14 Date 2006 Site Species.

Leaf stage

Leaf length (cm)

New Growth

Old Growth New growth

only Total

Agsp 2.8 18 April 12 Chopaka Exclosure Stco 1.2 9

- - - -

Agcr 3.5 16 April 12 Nighthawk

Stco 1.7 11 100 88 10 5.3

Agcr 3.25 48 April 12 South

Woodyard Stco 1.6 10 88 248 11.4 3.0

Stco 2.5 15 Brte 7 April 12 Dump Agsp 4.0 32

184 132 5.4 3.2

Two of the pastures contained old crested wheatgrass seeding that were unproductive and reverting back to native cover. Downy brome was prevalent at Dump pasture.

Turn-out pastures were in early-seral and highly at risk to non-functional. They had poor residual cover and lacked cryptogams. Soil compaction at the surface and at the 10 cm depth exceeded the root-restricting threshold at all sites regardless of soil texture.

Readiness criteria by leaf stage were met for crested wheatgrass on two sites and for bluebunch wheatgrass at the Dump pasture site.

Forage production was very low on these sites with total production (new growth and residual) ranging from 188 kg/ha to 336 kg/ha. This equates to a carry capacity of 5.3 to 3.0 ha/AUM.

13 Oven dried weight, dried at 50o C for 24 hrs. 14 Based on forage consumption of 10 kg/day dry matter (2.2% of body weight). A lactating cow consumes about 2.4% of body weight in dry matter daily. Carrying capacities are based on safe use factors of 30% for early seral communities, 50% for mid seral to PNC and 75% for healthy CWG/Alf.

9

Kamloops Forest District Turn-out pastures were in mid-seral to PNC stages. One pasture was moderately at risk, one slightly at risk, and the remainder at proper functioning condition. Soil compaction at the surface and at the 10 cm depth exceeded the root-restricting threshold at all sites regardless of soil texture.

Table 3. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Kamloops Forest District.



Soil texture

Root restricting threshold g/cm³

Soil strength g/cm³

Soil EC (mS/m) slurry

Soil temp.(0C)

Top 2.15 1 cm 0.19 April

25 PP Juniper Early MR Silty loam 1.55

10 cm 4.88 82 18.7


25 Oregon Jack 1 Mid PFC Silty

loam 1.55 10 cm 1.16

53 19.5

Top - 1 cm - April

25 Oregon Jack 2

PNC Basin wild rye

PFC Clay - 10 cm -

332 -


25 River Range North Late PFC Silty

loam 1.55 10 cm 4.1

60 23.5


25 Barnes S Mid MR Silty loam 1.55

10 cm 4.52 52 21.2

Top - 1 cm - April

26 Deer West Mid PFC Sandy loam 1.75

10 cm - 104 13.6

Top - 1 cm - May

3 Deer East Late PFC Silt loam -

10 cm - - -

Top - 1 cm - May

3 Westside Mid SR Silt loam 1.55

10 cm - - -

Top - 1 cm - April

26 Battle Creek Mid HR Sandy loam 1.75

10 cm - - -

10

River range- bluebunch wheatgrass big sagebrush grasslands

An open Ponderosa Pine bluebunch wheatgrass community

Grassland invaded by Blue mustard Chorispora tenella

Lower grasslands with Big sagebrush

Figure 8. Representative photographs from the Kamloops Forest District.

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Table 4. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Kamloops Forest District.

Readiness Production (kg/ha)

Carrying capacity.(ha/AUM)

Date 2006 Site

species, leaf stage

length (cm)

New Growth

Old Growth

New Growth

Only

Total

Agsp 4.5

Posa 2.0 April 25

PP Juniper

Brte 3.0 ` -

April

25 Oregon Jack 1

-

April

25 Oregon Jack 2

-

Agsp 4 Stco 2.5 April

25 River Range North Posa 2.5

264 327 2.3 1

Agsp Posp April

25 Barnes S

-

Agsp 4 24 Stco 2.5 7 April

26 Deer West

Brte 3 3 186 721 3.2 0.7

Agsp 3.5 Agcr 4.0 May 3 Deer East Brte 4.5

-

Agsp 3.5 30 Stco 2.0 9 May 3 Westside Kocr 2.5 5

233 549 2.6 0.8

Agsp 3.5 22 Stco 2.5 12 April

26 Battle Creek

Arlo 1.0 6 -

Readiness by leaf stage (4.0 leaves, bluebunch wheatgrass) was met at five of seven sites. On two sites, bluebunch wheatgrass was at the 3.5 leaf stage and growing rapidly.

Forage production was good on most sites, ranging from 591 kg/ha to 907 kg/ha. This equates to a carrying capacity of 1.0 to 0.7 ha/AUM. Residual cover from the previous growing season comprised the majority of the available dry matter, ranging between 55% and 80% of the total dry matter. Periodic planned rest is part of the grazing rotation for these pastures.

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Cascades Forest District We visited only one site in this district on May 3. The pasture was moderately at risk and in mid-seral stage. Range readiness by leaf stage had not been achieved (2.5 compared to 4.0 for bluebunch wheatgrass); however, portions of this pasture had good residual cover with 1,014 kg/ha dry matter (69% of the total). The carrying capacity equated to 0.6 ha/AUM based on total dry matter. We visited the site again on May 25 after livestock removal. At this time, blue bunch wheatgrass was at the 4.0 leaf stage. Soil measurements were not taken. Table 5. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Cascades Forest District.



Soil texture




Soil temp.(0C)

Top 1 cm May

3 W. Heifer 1 Mid MR Silty Loam 1.55

10 cm - -

Top 1 cm 10 cm

May 25 W. Heifer 2 Mid MR Silty

Loam 1.55

10 cm

- -

Table 6. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Cascades Forest District.

Readiness Production (kg/ha) Carrying capacity.(ha/AUM

Date 2006 Site

Species leaf stage

length (cm)

New Growth

Old Growth

New growth Only

Total

Agsp 2.5 20 Feca 2.0 19 May

3 W. Heifer 1 Feid 2.5 6

316 698 1.9 0.6

Agsp 4.0 Feca 2.5 May

25 W. Heifer 2 Posa 3.0

Low litter -

13

Central Cariboo Forest District We evaluated twelve sites in this district ranging from lower-elevation bunchgrass to mid-elevation Interior Douglas Fir (IDF) meadows from May 1 to May 3. In some pastures cattle had already passed through, in some cattle were present and in others, cattle had not yet arrived.

Table 7. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Central Cariboo Forest District.

Early use pastures where cattle passed through quickly had better cryptogam cover. Pastures where cattle stayed longer had lower cryptogam cover, less residual grass cover and lower seral conditions. Readiness criteria by leaf stage had been reached in the crested wheatgrass seeding, but not elsewhere.



Soil texture




Soil temp.(0C)

Top 0.27 1 cm 0.53 May 1 Fraser River 1

Kenworthy Mid PFC Silty Loam 1.55

10 cm 2.4 146 15.9

Top 0.27 1 cm 0.34 May 1 Fraser River 2

Coal Pit Mid PFC Silty loam 1.55

10 cm 2.26 148 13.3

Top 1.67 1 cm 1.71 May 2 Big Flat 1 Early HR

Loam 1.7

10 cm 1.67 77 7.5

Top 2.04 1cm 1.1 May 2 Flat 2

Grazed Early MR Sandy loam 1.75

10 cm 2.21 89 13.1

Top 1.26 1 cm 0.43 May 2

Big Flat 2 Exclosure 1990

- - Sandy loam 1.75

10 cm 1.77 77 13.8

May 2 Big Flat Breaks Early MR

Loam 1.7

- -

Top 2.05 1 cm 1.14 May 2 Rockpile Early HR

Silty loam 1.55

10 cm 2.03 82 12.2

Top 3.19 1 cm 1.37 May 2 Summer Range

CWG* grazed Seeded PFC Silty loam 1.55

10 cm 2.47 83 12.8

Top 1.44 1 cm 1.09 May 2

Summer range CWG* Exclosure 1994

Seeded PFC Silty loam 1.55

10 cm 2.15 10.7

Top 1.04 1 cm 0.75 May 3 Big Creek N Early MR

Silty loam 1.55

10 cm 1.68 72 14.1

Top 1.89 1 cm 0.34 May 3 Cow Lake

grazed Early - Silty loam 1.55

10 cm 2.43 80 10.4

Top 0.89 1 cm 0.41 May 3

Cow Lake exclosure (1990)

Early - Silty loam

1.55 10 cm 1.62

68 12.1

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Table 8. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Central Cariboo Forest District.

Readiness Production (kg/ha)

Carrying capacity.(ha/AUM) Date

2006 FD/ Site Species leaf

stage length (cm)

New Growth

Old Growth

New growth Only

Total

Agsp 3.7 27 Stco 2.0 12 May 1 Fraser River 1

Kenworthy Kocr 2.5 5

293 945 2 0.5

Agsp 3.9 25 Kocr 2.8 12 May 1 Fraser River 2

Coal Pit

152 665 4 0.7

Stri 1.25 7 Kocr 2.1 7 May 2 Big Flat 1 Posp 2.0 5

150 310 6.7 1.3

Stri 2.0 7 Kocr 3 5 May 2 Big Flat 2

Grazed Posp 2.0 5

-

May 2 Big Flat 2 Exclosure 1990

-

Stco 2.5 8 Kocr 2.0 8 May 2 Big Flat Breaks Agsp 3.7 20

-

Kopy 2.8 5 Agsp 2.75 15 May 2 Rockpile Stco 1.2 15

87 111 11.5 5.1

Agcr 3.5 15 Poco 2.25 7 May 2

Summer Range CWG* Grazed Mesa 7

493 599 0.8 0.4

May 2 Summer range CWG* Exclosure 1994

-

Stri 1.5 5 Stcu 1.25 5 May 3 Big Creek N Agtr 2.0 4

64 186 15.6 4

May 3 Cow Lake grazed -

May 3 Cow Lake Exclosure (1990)

-

The highest forage production occurred on a native grass stand in Churn Creek Protected Areas (Kenworthy at 1,238 kg/ha equating to 0.5 ha/AUM) and on a healthy crested wheatgrass-alfalfa seeding (1,092 kg/ha equating to a carrying capacity of 0.4 ha/AUM).

On the remaining native range, forage production varied from 198 kg/ha (5.1 ha/AUM) to 817 kg/ha (0.7 ha/AUM). Higher production correlated with higher seral-stage and functionality ratings. In all cases residual cover from the previous year comprised the majority of dry matter (ranging from a low of 56% to a high of 81%).

Soil compaction at the surface and at the 10 cm depth exceeded the root-restricting threshold at most sites regardless of soil texture. Kenworthy and Coal Pit had very low surface compaction mainly due to the healthy cryptogam layer.

15

An interesting comparison can be made between exclosures and adjacent grazed sites. In all cases the exclosures (Big Flat 2, Summer Range and Cow Lake) had lower soil compaction readings at the surface and at the 1 cm and 10 cm depths.

We observed that junegrass was the preferred and selected species on the lower elevation range, even though bluebunch wheatgrass was taller (15 to 27 cm) and more abundant. This is likely because junegrass did not have stemmy old material from the previous growing season. There is no readiness criterion for junegrass in the Range Planning and Practices Regulation, but the 4-leaf stage is recommended15 where it is the key grass species.

Figure 9. Healthy lower elevation bluebunch wheatgrass with a healthy cryptogam layer

Figure 10. Early-seral, HR mid-elevation grasslands with reduced cryptogam layer.

15 Fraser, D.A. 2006. Determining range readiness and growing degree-days (GDDs). BC Ministry of Forests and Range. Rangeland Health Brochure 11.

16

Figure 11. Mid-upper elevation grassland opening in a Douglas-fir forest.

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Peace Forest District The Peace region has the latest spring turn-out dates because of geography. We evaluated grassland/shrub communities there on May 10 and 11 prior to scheduled livestock turn-out. None of the sites was deemed ready for livestock use and grass leaf-stage, tiller length and volume were not adequate. Forage production ranged from 59 kg/ha and 86 kg/ha (>10 ha/AUM) to 743 kg/ha (0.8 ha/AUM) in the Beaton exclosure.

Residual cover from the previous growing season comprised the majority of the available dry matter, ranging between 67% and 74% of the total dry matter, except on a severely grazed Wilder Creek site where old growth comprised only 44% of the total dry matter.

Table 9. Seral stage and soil physical and chemical properties of the spring turn-out pastures in the Peace Forest District.



Soil texture




Soil temp.(0C)

Top 2.84 1 cm 2.16 May

10 Miller Range W Mid SR Silty clay

loam 1.5 10 cm 2.6

41 14.6

Top 1.58 1 cm 1.49 May

10 Dunvegan Late PFC Silty clay loam 1.5

10 cm 2.61 95 17.6

Top 2.45 1 cm 2.14 May

10 Kirkpatrick Mid MR Silty clay loam 1.5

10 cm 2.14 93 20.1

Top 4.04 1 cm 2.41 May

11 Farrell grassland Mid HR clay loam 1.65

10 cm 5.21 50 17.4

May

11 Farrell aspen Mid HR clay loam 1.65

- -

Top 9.85 1 cm 8.24 May

11 Wilder Creek Early HR/ Silt loam 1.55

10 cm 10.25 55 17.9

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Table 10. Range readiness, productivity, and carrying capacity of the spring turn-out pastures in the Peace Forest District.

Readiness Production (kg/ha) Carrying capacity.(ha/AUM) Date

2006 Site

Species leaf stage length (cm) New

Growth Old Growth

New growth Only

Total

Agda 3.0 17 Kopy 2.9 4 May 10 Miller

Range W Agtr 1.9

-

Agtr 2.25 12

May 10 Dunvegan Stsp 2.5 10

195 548 3.1 0.8

Stri 1.5 15 Agda 2.0 14 May 10 Kirkpatrick Stsp 1.5 15

183 366 3.3 1.1

Agda 1.8 7 Stsp 1.75 4 May 11 Farrell

grassland

18 41 33 10.2

Brpu 3.1 14 Agtr 1.5 10 May 11 Farrell

aspen Elin 1.8 18

-

Agda 2.0 7 Agtr 1.5 12 May 11 Wilder

Creek Stco 1.5 5

48 38 20.8 11.6

Use by wild ungulates was heavy on open grasslands and shrublands. In most cases grasses were grazed to 2 cm or less and there was low surface litter. The form and stature of the shrubs indicated recurrent severe browsing.

Soil compaction at the surface, at 1 cm, and 10 cm depths exceeded the rooting restriction threshold at all sites. In the Beaton exclosure, where livestock have been excluded since 1997, recovery is occurring, but surface and 10 cm measurements still exceed the threshold. Surface erosion was also noted on hill slopes. Snow patch area had good cover of western porcupine grass.

Figure 12. Soil erosion, poor residual cover and soil compaction were common.

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Figure 13. Heavy spring use by wildlife was common on south exposures.

Concerns Soils Compaction can improve the water holding capacity of sandy soils. However, in most soils compaction reduces the capacity of the soil to hold water, limits infiltration, increases runoff and leads to soil erosion. It can restrict plant rooting depth and cut-off access to moisture and nutrients lower in the soil profile. Compaction can also alter soil temperature, and combined with altered moisture conditions lead to disruptions in the mineral cycle and in the biological breakdown and incorporation of organic matter. Recovery from soil compaction can take decades.

The freezing and thawing action in winter may not be as effective in combating compaction as was once thought. Plant roots (fibrous grass roots, and tap-rooted forbs and shrubs) and burrowing small mammals and invertebrates all help in breaking up compacted layers.

Soil compaction was severe enough to restrict plant root growth and water infiltration on almost all sites, regardless of soil texture. Fine textured soils (with high clay or silt composition) were the most severely compacted. Range reference areas (RRAs) that had been protected from grazing for twelve to sixteen years were in a recovery mode, but were still slightly compacted at the 10 cm depth.

Biological soil crusts

We found that many turn-out pastures either lacked or had an altered biological soil crust (cryptogam) layer. Biological soil crusts (BSCs) should not be confused with physical soil crusts that form as a result of raindrop impacts on bare soils. BSCs, including lichens, are important in healthy functioning mineral and water cycles. An absent or altered cryptogam layer means that the carbon and nitrogen cycles are not functioning well. An intact BSC layer will provide a uniform distribution of nitrogen, which is released and available for early spring grass growth. Native legumes are scattered and deep rooted and cannot provide the same distribution or timely release of nitrogen as BSCs. This is probably why many interior rangelands are nitrogen poor. The role of BSCs warrants further study.

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Close-up of cryptogam cover A nitrogen-poor site with green urine and dung patches.

Cryptogam cover with low litter An early-seral plant community with no cryptogams.

Late-seral bluebunch wheatgrass Cryptogams and litter at the base of a rough

fescue plant. Figure 14. Biological soil crusts (cryptogams) perform an important function in grassland plant communities.

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Plant communities and available forage Forage volumes (combined new growth and old residue) ranged from a low of 188 kg/ha (5.3 ha/AUM) to a high of 1100 kg/ha (0.4 ha/AUM) on a domestic seeding.

In all cases residual cover from the previous year comprised the majority of dry matter and without it cattle would not have had enough volume, even when new growth had reached a height of 15 cm (6”). The healthiest and highest producing native turn-out pastures had planned rest as part of their grazing rotation. Higher production correlated with higher seral-stage and rangeland health ratings.

Competition for forage On some spring turn-out pastures in the Peace Forest District, we found that deer had grazed the new grass growth to below 2 cm. Shrubs such as saskatoon were also heavily browsed and under 15 cm in height. Heavy use by wild ungulates in these pastures has contributed to early seral conditions, bare soil, erosion and low grass volumes. This heavy use also means that shrubs are low stature and unavailable as browse in winter when there is snow cover.

Residual grass cover from the previous growing season is critical on early spring range. Without it, livestock do not have sufficient quantity of forage. Residual cover also insulates new tillers from temperature extremes and helps in the capture and storage of moisture.

Recommendations The healthiest and highest producing turn-out pastures had planned rest as part of their grazing rotation. Residual cover from the previous year is important to the spring forage balance. Without this residue, most pastures do not have enough forage to support cattle in early spring even when new tillers have reached 15 cm (6”) in height.

Incorporation of domestic forages such as crested wheatgrass or meadow brome into a grazing system will usually give a three-week head-start to the grazing season

Soil compaction can be countered over time, in part by controlling access when soils are saturated, but also by moderate use that allows the incorporation of plant residue and the development of a deep-rooted plant cover.

Where wild ungulates are preventing range agreement holders from using their spring range, the issue needs to be raised with the district range staff and with local Ministry of Environment staff.

We recommend the following:

1. Continue to monitor spring turn-out pastures. Focus efforts on spring pastures that also receive heavy late winter and spring use by wild ungulates;

2. Investigate the role of cryptogams in supplying nitrogen to rangeland systems;

3. Continue to monitor plant community recovery in range reference areas;

4. Continue to monitor the late winter and early spring use of Churn Creek Protected Area, as the current pattern and level of use seems to work well at this elevation; and,

5. Implement planned rest on early spring pastures that are early-seral and highly at risk to non-functional. These pastures require a build up of organic matter as the first stage to recovery and that can only occur if they are ungrazed for a period of time.

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Appendix 1. Excerpt from “The Range Resources Assessments Procedure” How to use the function checklists The checklists should be reviewed in advance of fieldwork and any necessary file or historic information should be gathered and recorded at that time. Generally, you should get a feel of the area by walking a stream reach or traversing an upland area before filling in the checklists or forms; this will help to gain a broader perspective which otherwise may be lost if you become too concerned with making notes. Look for relic areas or areas where livestock use has been light in order to determine site potential Use the field checklists in assessing for proper functioning condition (PFC) at the reconnaissance level. To qualify as functioning properly, riparian (including the feature) and upland areas must satisfy the general conditions outlined in Section 6 of this guide, and the answers to the majority of statements in the checklists must be “Yes”. An area is “at risk” when functioning at some level, but a combination of attributes makes it vulnerable. A score of “at risk” may trigger some follow-up action (e.g. more detailed monitoring or a change in management) or, if an upward trend emerges, may verify that the management prescription is working. An area is “non-functional” when the criteria in Section 6 are not met and degradation is occurring. The following table can be used to score the area being assessed. Pay particular attention to categories that give borderline answers as these indicate trend, and may serve as either early warnings or indicators of recovery in damaged systems.

% of Yes answers Rating

Yes ≥ 80% PFC

61-79% Slightly at risk

41-60% Moderately at risk

20- 40% Highly at risk

Yes < 20% Non-functional

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Appendix 2. Uplands Function Checklist

Range Unit: Range Agreement Holder: Range Agreement Number: UTM Coordinates:

Name of Upland Area: BEC Subzone: Date: Location: Hectares: Observers: Yes No N/A Parameters Hydrologic and Soils Organic material (plant litter, standing vegetation) protects soil surface

from raindrop impact and evaporative effects of sun and wind. Water will easily infiltrate the soil surface (absence of physical soil

crusting, capping). Subsurface soil conditions support infiltration (compaction layers are

uncommon). Standing vegetation and plant litter detain overland water flow and trap

sediment. Non-stream ephemeral drainages are stable (sufficient vegetation is

present to protect against downcutting). Biotic/Vegetation The plant community is showing good vigour. There is recruitment of desirable plant species (new seedlings). The plant community reflects a fully occupied root zone. Seeps, springs, and ephemeral drainages support vigorous stands of

phreatophytic plants. Biological breakdown of plant residues/organic material is apparent

(decomposition as opposed to oxidization). Biological breakdown of livestock dung is rapid. A diversity of vertebrate and invertebrate life is evident. Erosion/Deposition Evidence of rills, gullies, pedestaling and other excessive soil movement

is uncommon. There is little visual evidence of pedestaling of plants or rocks. Pedestals

present are sloping or rounding and accumulating litter. Notes:

Is the desired plant community present (diversity - - species, comp., age classes, structure, form)? Soils types and textures?

Check one

PFC ____

At risk ____

Non-functional ____

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Appendix 3. Description of Plant Communities and Habitats

Browse utilization

Browse Use Categories – current year’s growth List of preferred browse species on site

Light – 0-10% Moderate 11-40% Heavy >40%

Stubble Height m transect. Measurements taken every paces. Pattern of Use: Measurements along transect:

Max. height Min. height Ave. height




Notes – (Plant community, structure, recruitment, litter, bare ground, invasive species)

Current Plant Community Desired Plant Community

Lightly Browsed

2 year-oldwood

Moderately Browsed

2 year-oldwood

2 year-oldwood

Heavily Browsed

Robel Pole Measurements ___ m transect. Measurements taken every ___ paces.

Max: ____ Min: ____ Average: ____ Photo Number

Invasive Plants Species

Size of infestation: <100 m2 10-2,500 m2

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Appendix 4. Plant Community Description Form Site name or map sheet __________________________Date______________________

Observer _____________Photo # ______________

Plant Community

Dominant grass species

Dominant forb species

Dominant shrub Species

Dominant tree species

Phenology of Indicator Grasses/length

Phenology of Indicator flowers

Phonology of Indicator shrubs

Missing Layers Missing Species

Litter

Comments on impact of livestock grazing on the plant community

Stubble Height (circle high and low for each species. * Ungrazed)

Species #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 Mean

Ungrazed Height

Shrub Use (record percent use and form class for 10 twigs)

Form Class Species % use L M H Notes:

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Appendix 5. Staff participating in the evaluation District Branch Staff District Staff Cascades Forest District Rick Tucker P. Ag.

Nick Hamilton.

Central Cariboo Forest District

Doug Fraser P.Ag Francis Njenga P.Ag. Andrew Pantel P.Ag.

Chris Armes P.Ag.

Kamloops Forest District Rick Tucker, P.Ag. Francis Njenga P.Ag. Laura Blonski P.Ag.

Mike Deedles P.Ag. Jim Fox P.Ag.

Okanagan-Shuswap Forest District (Penticton)

Doug Fraser P.Ag. Rick Tucker P.Ag.

Rob Dinwoodie P.Ag.

Peace Forest District Laura Blonski P.Ag. Francis Njenga P.Ag. Doug Fraser P.Ag. Andrew Pantel P.Ag. Honey-Marie Giroday

Keith Carroll P.Ag. Jason Labonte A.Ag.

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Appendix 6. Scientific name, four letter code, and common names of plant species. Scientific name Species code Common name Agropyron cristatum Agcr Crested wheatgrass Agropyron dasystachyum Agda Northern wheatgrass Agropyron smithii Agsm Western wheatgrass Agropyron spicatum Agsp Bluebunch wheatgrass Agropyron trachycaulum Agtr Slender wheatgrass Aristida longiseta Arlo Red three-awn Bromus pumpellianus Brpu Pumpelly (northern awnless) brome Bromus tectorum Brte Downy brome Calamagrostis rubescens Caru Pinegrass Danthonia intermedia Dain Timber oatgrass Festuca campestris Feca Rough fescue Festuca idahoensis Feid Idaho fescue Koeleria pyramidata Kopy Junegrass Poa compressa Poco Canada bluegrass Poa pratensis Popr Kentucky bluegrass Poa sandbergii Posa Sandberg’s bluegrass Poa sp. Posp Bluegrass species Stipa columbiana Stcol Columbia needlegrass Stipa comata Stco Needle-and-thread grass Stipa curtiseta Stcu Western porcupine grass Stipa occidentalis Stoc Stiff needlegrass Stip richardsonii Stri Spreading needlegrass Stipa spartea Stsp Porcupine grass Stipa viridula Stvi Green needlegrass Medicago sativa Mesa Alfalfa

an evaluation of early spring turn-out on · shrubs such as saskatoon were also heavily browsed and...

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