This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. Health of Idahos Forests .1 A summary of conditions, issues and implications

May 1999

LIST OF AUTHORS:

David Atkins, M.S. - USDA Forest Service - Ecologist James Byler, Ph.D. - USDA Forest Service - Pathologist Ladd Livingston, Ph.D. - Idaho Department of State Lands - Entomologist Paul Rogers, M.S. - USDA Forest Service - Ecologist Dayle Bennett, B.S. - USDA Forest Service - Entomologist

USDA Forest Service Northern Region Forest Health Protection Report No. 99-4 The desire for lasting and healthy forests in which to live, work and play is something we all share - not only in Idaho but across our nation. In Idaho we have a number of forest health issues confronting us, our forest ecosystems are not as resilient as desired and the ability to sustain our communities is at risk. To facilitate effective strategies to resolve these issues we need to have a good inven­ tory of the forest condition and the ability to track changes through time. The nationwide Forest Health Monitoring program initiated in 1990 was the tool designed to provide that information. Idaho Department of State lands, and the three divisions of the USDA Forest Service - Research, National Forest System lands, and State and Private Forestry partnered to produce this comprehensive look at the health of all of Idaho's forests. Idaho was the 19th state added to the program in 1996. The program utilizes existing ongoing informa­ tion efforts and establishes plots across all forests - Federal, State, and private. From this information Forest Health specialists are able to monitor and assess the long-term status and change in forest conditions. These plots provide scientifically sound information that helps meet the needs of private landowners, policy makers and land managers. We believe that reasoned decisions can be made about how to manage our forests, by using good information. We hope this publication provides the necessary scientific basis from which private and public land managers and citizens can engage in a meaningful dialogue about the health of Idaho's ~orests.

Z4kdf ~",?~tk ;::::::>~ IA· 6#. -- fJ-Jack Blackwell Stan Hamilton Dale Bosworth Denver Burns Intermountain Idaho State Northern Region Director Regional Forester Forester Regional Forester Rocky Mountain Research Station of Idahos Forests

INTRODUCTION ...... 1 Wllat is a Healthy Forest...... 1 Measuring Forest Change...... 2 How We Monitoring Forest Health ...... 2 The FHM Plot Network ...... 2 Aerial and Ground Surveys ...... 2' Vegetation Inventories ...... 2 Forest Health Assessment ...... 3 Scope of this Report ...... 3

THE RESOURCE ...... 5 Forest Types ...... 5 Land Ownership ...... 5 Ecoregions of Idaho ...... 6 Northern Rockies ...... 6 Great Plains (Palouse Dry Steppe) ...... 6 Middle Rockies ...... 6 Southern Rockies...... 7 Intermountain (Semi-Desert) ...... 8

CHANGING CONDITIONS ...... 9 Ponderosa Pine ...... 9 Western White Pine ...... 10 Western Redcedar-Western Hemlock ...... 12 Western Larch ...... 12 Douglas-fir ...... 12 Lodgepole Pine ...... 13 Aspen ...... 13 Grand Fir ...... 14 Whitebark Pine ...... 15 FOREST HEALTH ISSUES ...... 16 Exotic Introductions ...... 16 White Pine Blister Rust ...... 16 Balsam Woolly Adelgid ...... 17 Non-Native Invasive Plants ...... 17 Watershed Health ...... 18 Wildland Interface Development ...... 18 Forest Growth ...... 20 Insects and Disease ...... 21 Root Disease ...... 21 Dwarf Mistletoes ...... 22 Bark Beetles ...... 22 Defoliators ...... 23 Fire ...... 24 Biodiversity ...... 26

MANAGEMENT IMPLICATIONS ...... 27 Forest Health Issues ...... 29

LITERATURE ...... 31

APPENDICES Appendix A - Summary of the 1996 Surveys ...... Al Appendix B - List of Further Contacts ...... Bl 1 Introduction

daho's image is largely a refl ection of its landscapes: its mounta ins and valleys, ri vers and lakes, fi elds and plains, an d especiall y its fo rests. People identi fy with that landscape and the forests aestheti cally and culturally as offering both a desired life-style and/or as a way of making a living.

WHAT IS A HEALTHY FOREST? Regardless of how people view Idaho's fo rests, the health of these forests is vi tal. Bu t what is a healthy forest? Healthy compared to what? By what criteri a? There are many definitions and concepts beca use how one views fo rest health is a reflecti on of personal va lues. In urban forests or in campgroLmds, agents of change, like disease, fire, insects and \'\!eather damage are often Lmdesirable. They put our faciliti es as well as visitors at some level of ri sk. However, in vvilde111eSS areas these same elelnents are considered desired components of a fLmctioning ecosystem. It is our use or objective in managing the forest that determines how we view these agents of change as desirable or Lmdesirable. In searching fo r defining elements of a healthy forest, we might consider a forest Lmhealthy if it loses the ability to maintain or replace its LUugue species or functions. One way scientists have assessed whether a system is LU1healthy is by Two concepts important in defining forest compari.ng current conditions with the normal health include (Kolb and others 1994): range of dynami cs the system has experi enced Ecologica l: A healthy forest mai.ntains its tlu"Ough the past. TI1.i S concept is referred to as the Lmique species and processes, while historic range of variability. Change can be maintauling its basic structure, composition determined using teduugues such as permanent and hmcti on. monitoring plots, fire h.i story analyses, old h.i storical photo records or studies of poll en and Social: A healtl1Y forest has the ability to charcoal la yers in bogs or lakes. These various accommodate current and future needs of pieces of information are then integrated with our people fo r va lues, products and services. understanding of the dynamics of the ecosystem. The ability of a forest to sustain itself These components are i.nex ti-icably liI1ked. ecologically and provide what soc.iety wants and Forests cannot meet social needs without needs is what defines a healthy forest. possessing the sustau1ed ca pacity to grow, Maintaining that balance between fo rest reproduce, recycle nu trients, and carry aLIt sustain ability and producti on of goods and other ecological fLmcti ons. services is the challenge for owners and managers of the states' fo rests. 2 MEASURING FOREST CHANGE Ground The starting point in evaluating forest health is measuring the change in forest conditions. Forests are dynamic ecosystems in constant Aerial Surveys: From aircraft, state or Forest transition. Some changes are caused by natural Service observers record detectable tree damage. mechanisms, such as fire, windstorm or insect Tree damage and mortality caused by bark beetles, activity. Others are the result of human actions. defoliators, some pathogens (primarily needle or While many of these changes are perfectly leaf diseases), and weather-related disturbances acceptable, even essential, others go well beyond are monitored annually through aerial detection what people are willing to tolerate, based on their surveys. values. Thus, changes are filtered through a value Low level reconnaissance surveys have been system with subsequent implications. conducted over most forested lands in Idaho since The purpose of this report is to provide a the 1950s. The surveys provide an efficient and summary of the changing conditions of Idaho's economical method of detecting and appraising forests and the issues and implications raised by recognizable damage over large forest areas. those changes. Such information is valuable in displaying disturbance trends over time and from place to place. However, many of these damages are HO\tV WE MONITOR FOREST extremely variable and often difficult to detect and HEALTH quantify accurately. Ground Surveys: Ground surveys are Forest Health Monitoring (FHM) is a conducted by state and Forest Service specialists nationwide program that provides information to detect and monitor the location, extent, severity, over the long term on forest conditions, processes change and trend in large-scale tree damage and and trends. It then interprets what that data mortality caused by insects, pathogens, fire and means for forest health from a variety of other agents. perspectives. These surveys may include routine field We recognize that forest health is a complex surveillance, insect population sampling, or issue. The different sets of criteria used in biological evaluations. determining a healthy forest is complex as well. For these reasons, we have included information Purpose Specific Permanent plots: For a that will assist you in deciding when a forest is number of pathogens and insects, plots have been healthy, when it is unhealthy, and why. established in infested or susceptible stands to Data for this and ensuing reports will come monitor tree damage or mortality rates over time. from a variety of sources: Such plots provide data to quantify the influence of pathogens and insects on stand composition FHlvI and structure, and to evaluate effects of In 1996, the USDA Forest Service and the treatments. Idaho Department of Lands established permanent FHM plots across Idaho's forested lands to gain a baseline measurement of forest Data from a variety of vegetation inventories conditions. A plot is defined as a permanent are available for use in assessing forest health. sample location, remeasured on a regular cycle. These include Forest Inventory and Analysis (FIA) Within those plots, rigorously trained field data, established by the Forest Service Research crews gathered data on tree diameters, crown branch and available from plots established on all conditions, tree damage and lichen communities, ownerships; National Forest System (NFS) stand all of which are used as indicators of forest health. and forest inventory data, available for Forest In the coming years, crews will remeasure the Service lands; timber growth and yield plots original set of plots on a four-year cycle, allowing maintained by NFS. researchers to assess trends in forest conditions. As the program develops, new indicators, such as soil conditions and understory vegetation will be added to supplement the current measurements. ------3

Much of the historic data was focused on tree with difficult issues underlying them. This report or stand damage, and effects on commodity will present some of the more significant issues. outputs. Recently, attempts have been made to However, the ultimate solutions to the problems evaluate forest condition, health and trends. Thus, surrounding forest health will depend largely on attempts are underway to use various data to public understanding of the trade-offs involved. assess not just past damage, but current conditions We will conclude our study by highlighting and to make predictions of future conditions. those areas of special concern. For those In this report, we have attempted to describe interested in more detailed information, conditions broadly and to compare and contrast additional tables are presented in the appendices. current conditions with those of the recent past. Please refer to FHM contacts listed in Appendix B This description provides a perspective on how for answers to questions or further information. forests have changed and offers a basis for predicting trends. The understanding of historic and prehistoric conditions and processes that maintained them provides a useful way to assess unhealthy condition. Information from these other sources of information is useful in monitoring changes occurring between FHM plots and in assessing the causes of disturbance. Data from the plots can also be used to determine forest areas at risk.

In our investigation of Idaho's forest health issues, it is important to begin with defining the resource ecologically and by ownership. First, we will describe the state's forest cover and land ownership patterns on a broad scale. Next, we will take a more detailed look at ecological regions, or ecoregions, within the state. Examining ecological divisions are an important step in helping us understand and address forest issues that cross ownership, political and agency boundaries. A brief summary of the data collected on the FHM plot network is included to give you a better idea of forest composition statewide. The body of this report will focus on changing conditions and their important forest­ related issues in Idaho. For example, are wildfires a threat or an asset to forest health? What effect do these fires have on human health and safety? Do the answers change with proximity to population centers, or to isolated home sites? Are forests in Idaho similar to those in this region 100 or 200 years ago, or are they changing? If there are changes, how should we view them? Are changes

If good" or Ifbad"? These are difficult questions, Figure 1. Forest Types in Idaho.

Legend

Aspen Coyer Type ~ Cottonwood IlMlow COYlr Type C) EngeImaM Spruce I Subalpine ftr Cover type .. Grand Ar I WhIte FIr Cover Type

.. Intertor Douglas-ftr Cover Type G.::) Interior Ponderosa PIne Cover Type ~ Juniper Woodlands Cover Type C> UlT\l)flf Pine Cover Type c=) Lodgepole PIne COvaf Type c:=:> Mlx:ed Conrter Woodlands Cover Type .. Mountain Hemlock Covllr Type C) Western Lareh Cover T)1)1I .. Western Red Cedar J Western Hemlock Cover Type ~ Western Whnll Pilla Cover Type ~ Whlrebal1lPWleCowrType

C) Other Forest Coyer Types C) Sagebrush/Gras9land Covar Type Idaho Ecoreglon Booodaria, ) ------The Resource

n disCLI ssillg the health of Id aho's forests, we Figure 3. are dealing with many forests types. From the moist cedar-hemlock forests of the Panhandle to the dry j lU1.i per woodlands in Owyhee COlm ty, Idaho's forest lands are State of Idaho guite varied. We also will portray that variety ill terms of land ownership fU1d ecological regions. Ownership Owner Private Forest Service BlM FOREST TYPES _ State Other Figure 1 depicts the distribution of forest _ Lakes types across the state of Idaho. In this publication, we use forest type synonymously with cover type, or the dominant tree species at a given site. Forest types are influenced by a number of factors, including cl im ate, elevation, aspect, soil type, and recent disturbance. '. TI,e accompanying chart shows the ~ . percentages of fo rested area covered by the primary forest types iJ1 the state (Figure 2) . , . -'i. , •, -, !J'-:::" ... .', . , Figure 2. , \ ."

'. , ~ , '\~ , ~. ..-.... /'. Idaho Forest Types '- --... "" .-

l Oougos lir l - ' .

Figure 4 .

Percent Forest Land Ownership I Lodgepole PInel TrbalO.S% State 4.8%

I Privals 9.3%)

LAND OWNERSHIP Figme 3 di splays the patterns of forest land ownership ill the state, while figure 4 presents land ownersh.ip as a percentage of total land. 6 Vegetation in this province is unique to the Inland West primarily because of precipitation As land management agencies and private and soil patterns which more closely resemble the land owners begin to work together at state and Pacific Northwest. Prior to European settlement regional scales, it seems logical to approach forest much of this area was almost entirely forested. management issues using "ecoregions," or land Today, the most common forest types are divisions where ecological conditions are similar. Douglas-fir, grand fir, and cedar-hemlock. The In recent years, managers have adopted forest understory is characterized by a lush cover ecologically based land management practices of ferns, forbs, and regenerating trees. Certain and incorporated mapping systems based on lichens are also quite rich in comparison to other ecological principles. ecoregions of Idaho. Bailey's (1995) Description of the Ecoregions of ·Great Plains Province: Palouse Dry Steppe Province the United States presents a hierarchical framework for logically delineating ecological regions based This province comprises the Idaho portion on their unique combinations of physiography, of the Palouse region, which extends into eastern soil type, potential vegetation, and climate. The Washington. Its topography is characterized by ecoregions of the United States are delineated, in rolling hills and flatlands, ranging in elevation descending orders of scale, by domains, divisions, from below 1000 to about 4000 feet. The lowest provinces, and sections. point in the state, at Lewiston, is 739 feet above sea In this report we will focus on the ecoregions level. of Idaho at the province level. There are five Average annual precipitation is about 15 distinct provinces found in the state. All of the inches, with most of that coming in the form of provinces of Idaho have some forested conditions winter rain or snow, and sporadic spring and and, therefore, have been sampled by the FHM summer thunderstorms. The lack of forested plot and aerial survey networks. environments is due mainly to the rain shadow Figure 5 shows the distribution of forested effect of the Cascade Range to the west and, sample points across the state by ecoregions. secondarily, to land clearing by humans. Descriptions of the five ecological provinces of Also known as the shortgrass prairie, the Idaho are discussed below. Palouse is a much smaller"sister province" to the Great Plains ecoregion. The vegetation is composed primarily of grasses, forbs, and small Provinces shrubs. (A "steppe" is a grass-covered semiarid plain.) ·Northern Rockies Province: Northern Rocky The forested component of the Palouse is Mountain Forest - Steppe - Coniferous Forest -Alpine small and mostly confined to moisture-holding Meadow Province aspects, or exposures, and draws. Forested areas The Northern Rockies are characterized by include scattered stands of ponderosa pine and rugged mountains, separated by flat valley Douglas-fir. Cottonwoods are found along bottoms. Relief within this province ranges from riparian zones throughout this province. Much of 3000 feet to over 9000 feet. Temperatures can be the Palouse has been converted to agricultural or severe but are often moderated by coastal urban uses and therefore will not reflect the native influences. Precipitation is generally greater than plant communities described for this province. throughout the rest of the Rocky Mountain region, averaging between 16-100 inches annually. Most of the moisture comes in the fall, winter, and . Middle Rockies Province: Middle Rocky Mountain spring, while summers remain relatively dry Steppe - Coniferous Forest - Alpine Meadow Province Soils are less rocky than surrounding mountain provinces in the West and have a Within Idaho, the province is defined chiefly distinct volcanic influence. These factors provide by the granitic intrusions that form the Idaho excellent soil conditions in the Northern Rockies, Batholith. The southern and eastern fringe of the and have a direct effect on the abundance of forest Middle Rockies are basin and range formations biomass. more similar to those of central Nevada. 7 Elevations generally range from 3000 to 9000 Lodgepole pine is common tlu'oughout the feet, although the highest peak in the state is region on a variety of aspects. At higher found in the Lost River Range, toppin g 12,000 feet. eleva ti ons Engelmann spruce and subalpine fir Precipi ta ti on is mostly in the fo rm of are the most common species. In the snowfall , with valleys receiving less than 20 inches northernmost reaches of the province, where armuall y, while the higher elevati ons receive about rainfall ar1d evaporation rates more closely 30 inches. resemble the Northern Rockies province, In contrast to the Northern Rockies, the nonforest lands are less common. ari dity and evaporation rates of the Middle Rockies often sharply defin e forest arld nonforest tracts. Both upper and lower treelines are . Southem Rockies Province: SOl/lhern Rocky common. Low and middle eleva ti on fo rests on !VIol/l/loill Steppe - OpCII Wood/olld - COlliferalls south and west facing slopes al·e often dominated Forest - A/pille !VIeadow Provillce by sagebrush semidesert conditions, whi le the opposi te aspects consist of Douglas fir, grand fi I; The Southern Rockies are confined to ar1d ponderosa pine, depending on locale wi thin southeastern Idaho and the the province. Yellowstone Plateau. Elevations range h·om 4,000 to just w1der 10,000 Figure 5. Ecoregions of Idaho feet. Intermontane valleys are composed mostly of developed Forested Field fa rmlands or sagebrush steppe. The climate of the Southern Rockies is best descri bed as highly . variable, depending on local Plots In eleva ti on and aspect. In general, valleys are wa rmer and dri e l ~ w ith armual precipitation of 15-25 inches Idaho per year. Hi gher mOlmtain ranges are much cooler and precipitation is 40 ind1es or more annuall y. Much of the moisture comes in , % the form of winter snow. The fl ora of Northern Rockies 36 25 this region is also highly va ri able. Palouse Dry Steppe 3 Because of constant changes in • Middle Rockies T7• 55 • • Semi·Oesen 10 7 elevati on and aspect-ar1d • • • Southern Rockies ,. 10 • • • • subsequently soil types, rainfall, and • • • evaporation rates-ITIollntain • • • • • vegetati on resembles a Imge-scale • • • • • • mosaic of conifers, hardwoods, and • • • • • • shrub/ grasslands . • • • e • • Southern Rockies forests are Midgle Rgckies • • • • • • • often depicted with spruce and fir • • • • • • domina ting the highest forested • • • • • elevations, lodgepole pine and aspen • • • • at mid-elevations, and Douglas-fir • • • • • and jlmiper defining the lowest • • forested zone. Although this holds • true generally, there are often • excepti ons based largely on aspect • Semi-Desert • • • and a sprinkling of less common • So•uftle • • • R cJsjes forest types, such as limber pine or • bigtooth maple . 8

. Intermountain Province: 5elllidesert Provillce The Intermountain Sernidesert Province covers most of the southern one-third of the state. TI1e area is dominated by the Snake Ri ver plain, although smaiJ er mOlU1 tain ranges abound. Lower va lleys are between 2000 and 4000 feet elevation, while sca ttered mOlu1tain ranges average between 7000 and 9000 fee t. Unlike the Rocky MOlU1tain Province, there is less variation in temperature or precipitation across the Semidesert Province. AI1J1ual precipitation is about 15 inches per yea r and is fai rl y evenly distributed through the seasons, except for summer when very little rain faiJs. The vegetation is composed primaril y of sagebrush, rabbitbrush, and bW1ch grasses. Riparian zones are Lin ed with cottonwoods, shrub­ form willows, and sedges. Forested areas are rather sparse, being composed primari ly of isolated mountain ranges of Douglas-fir, aspen, and juniper. In the southwest Owyhee Desert, there are large forests of western juniper with occasional stands of Douglas-fir or ponderosa pine. ------9 Changing Conditions Change is fundamenta l to a ll ecosystems. Forhmately vast areas of Idaho still exhibit Change can occur suddenly or over such a long intac t fo rests of nati ve tree species. While all period that no change is apparent in the short na tive h"ee species are p resent, in some areas term. proportions have changed substan tia ll y. Sti ll these TI,e process of vegetation change is called forests provide habitat fo r a large number of fo rest succession. "Disttlrbances," notabl y fire, native birds and other animals. These fo rests also insects, disease, climate and hLUnan ac ti vity, are hi ghl y va lued fo r their recrea ti onal i.nfluence the direction and rate of chan ge (Rogers opporttmities, wildness, and commodities they 1996). Without disttlrbance, forests change, but at produce. a different rate and diJ·ection. (Covington and others 1994.) Prior to European settl ement, fire was the primary means of vegetati ve change, ignited by Ponderosa Pine either American Indians or lightning. Settlemen t brought new agents of modifi cation. Timber harvesting aJld fire suppression were mean t to Historically, ponderosa pine forests provide income and products or to protect people predominated on warm-to-hot, dry sites at the and property. However, other changes were lower elevations along the east slope of the unintenti onal, such as the introduction of mOLmtains and in major river valleys in the daJl1aging diseases, insects or vegetatio n. Some Northem Rockies, Middle Rockies and Palouse lman ticipated side effects of intentional ac ti vities also have proved to be a negati ve, such as overly dense forest resulting from wildfire suppression.

Fiomlrp 6. Ponderosa Pine Distribution

'.

' . .' ':',

a. Historical distribution b. Current distribution

Legend

Pond&ros. Pine Cover Type 0 OtMr Forest Cov. Types - Idaho Eeoreglon 80underies 10 grassy, semi-a rid plains (steppe) Ecoregions Unlike tlle low-moderate ultensity fires of the (Figure 6a). Matme ponderosa pine forests were past, some wildfires now are lethal across large commonly quite open, a condition that was areas (Figure 7) with the potenti al fo r damaging ma ultained by intermittent low intensity fiTes the productivity of soils and increasing erodibility averaging every 5 to 25 years (Crane and Fischel; through ilie consumption of organjc matter and 1986). These surface fires conslU11ed the needle hjgh temperatures especially when coarse duff and killed most lU1derstory trees. Bark textured soils are uwolved. (Well s and other 1979). beetles killed individual or sma ll groups of aging or stressed trees, which were eventuall y replaced Figure 7. Severe Fire, Boise N.F. by regeneration that had survived the fires. Ponderosa pine is now less common, havul g been replaced by denser forests of Douglas-fir or grand fir (Figure 6b). Acreage decreased by 44 percent for Idaho as a whole during the peri od 1952-87 (Brow n and Chojnacky 1996). The change is a result of fire suppression and timber harvesting. Without fire, the more shade-tolerant Douglas-fir and g.rand fir become established and outcompete the ponderosa pine. Ea rl y harvesting of ponderosa pUle accelerated the shift Ul composition towmd Douglas-fir and grand fir. The net result has been a change from predominantly semi-open, mature ponderosa pUle forests to dense, YOlU1ger forests, many of whjch are multi-storied, shade tolerant species more susceptible to fire and disease. Western White Pine The changes Ul forest composition and In ldmo, western white pine occm s almost structLU'e have favored a Ilwnber o f native insects exclusively in the Northern Roc ki es Ecoregion and diseases. Douglas-fir d warf mistl etoe buiJds (Figure 8). UntiJ about 50 years ago, it was ilie up to high levels in dense, slow-growing stands most abundant forest type in that region. and when infected overstories provide an Prior to Emopean settlement, the landscape infecti on source for wlderstory trees. pattern consisted of large mosiacs of many Bark beetl es kiU ponderosa pine at increased thousands of acres, major porti ons of whjch were of a similar age class, a legacy of m..ixed-severity rates in the dense stands, especially during and large stand-replacement fires. White pine peri ods of drought. Defoljating Ulsect outbrea ks forests of 200 or more years of age were common, peri odica ll y occur, with most signjficant effects but so were newly regenerated small trees and OCCUlTing Ul multi-storied Douglas-fir and grand shrubs resultulg from recent burns, as were forests fiT stands. of an intermed ia te age. Da ta from the Coeur Altered forest structure and composition have d' Alene Basin indicates staJld replacement fires also increased risks from wiJdfire. Fire occurred at a given location every 150 to 250 years suppression has permitted grea tl y increased on the average (Zack and Morgan draft). Mixed ground fuels, with the multi-storied condition severi ty fires that killed only part of the stand crea tiJl g a "fuel ladder. " Fires often burn hotter occurred at about 60 to 85 year intervals. After a and more extensively than they d id in the past, long absence of fire, western redcedar, westem creating condjtions where man y fires can no hemlock, or grand fir-species most tolerant of longer be contained. shade-would eventually dominate a site. Prior to More than half a million acres bUl11ed fire su ppression, these species ra rely between ]989 and 1994 on ilie Boise Nati onal predom.inated except on the wettest sites because Forest. Ln the past, fires in ili.is forest type were of ilieir susceptibility to fixe. primariJy low to moderate intensity, and most of Today, the amOlmt of western white pi.ne is 93 the large ponderosa pine smvived. A relatively percent less than 40 yea rs ago, as displayed in small amOLmt of the forest burned severe enough fi gures Sa and 8b (Brown and Chojnacky 1996). to kill all the trees. 11 Figure 8. Western White Pine Distribution

, " . , o·

a. Historical distribution b. Current distribution

Legend

The causes of change include outbreaks of the Even though most trees will die from tl,e rust, mowltain pine beetle, fire suppression and some will live and may carry genes for rust harvesting (Byler et a1. 1994, Harvey et a1. 1995). resistance and other h'aits that are important to the The prin1ary agent of change, however, is tl1e eventual restoration of tl1e species. white pine blister rust. The rust, a disease of The numbers of plantings have not been white pines, did not formerly occur in North adequate to offset the rate of continuing loss of America W1til accidentally introduced into larger h'ees and the non-resistant natural Vancouver Island, British Columbia in about regeneration. Statewide inventory data show that 1910. By the 1940s, the disease was epidemic in mortalility is greater than growth for the species Idaho. Today, a combination of blister rust, (Brown and Chojnacky 1996). On federal lands, mowltain pine beetle and harvesting has nearly planting has decreased in recent years due to the eliminated mahlre westem white pine stands. decreased amount of regeneration harvesting. Remaining large westem white pines now exist The decrease in westem white pine is mostly as scattered individuals. The rust significant both economically and ecologically. continues to kill most trees that regenerate Economically, western white pine is the most naturally, and rust and bark beetles continue to valuable of timber species, and potentially can kill remaining large trees. produce greater biomass than its associates, Rust resistant western white pine strains have especially at ages over 100 years. been bred from wild white pines, which have In terms of the ecology of the species, western shown some level of genetic resistance. Rust white pine achieved large size and 200 years or resistant seedlings have been planted since the more of age. TI1US, it was the main component of mid-1970s, but tl1e amOLmt represents only a many old growth forests in the Northern Rockies small part of the area previously occupied. Province. Western white pine is resistant to root Natural regeneration is also encouraged rots that significantly affect many other tree where possible, mainly for gene conservation. species in this forest type. 12

Western Redcedar-Western Hemlock mixture with a wide range of other species. Statewide, the am ount of Douglas-fir cover type has increased modestly over past decades Western redcedar and westem heml ock occur (Brown and Chojnacky 1996). Rather large on very moist sites in the Northern Rockies. in creases have occurred in SOln e areas, h owevel~ Western red cedar has a similar range to the such as in the Northern and parts of the central historical range of western white pine. Westem Rockies where it has replaced westem larch and hemlock occurs on wette r, more northerl y sites westem white pine on many sites. It also has and has an even l110re restrk ted range. Both are become the predomi.nant species in locations very suscepti ble to injury and death from fire. The two species have increased greatly during past decades, as shown in fi gme 9. Wild fi re Figure 9. Cedar / Hemlock Distribution suppression, the bli ster rust, and selective harvest of white pine and larch have favo red conversion to cedar an d heml oc k. Performance of western redcedar and Legend western hemlock on dryer sites is not full y _ CGdar I HemIoc*: Cover Types lUlderstood because the stands are still rela tively o Other ForllSt Covill' Types yO lUl g. Of concem is their drought susceptibility. Idaho Ecaegion Boundaries Gro wth is generally less than species they replaced, especially when affected by root disease. And they are quite susceptible to stem decays, wl, ich significantly affects their value fo r fo rest products.

Western Larch Western larch occurs in the Northern Rockies Ecoregion and in the northeast porti on of the Middle Rocki es Ecoregion. It is very intolerant of shade but highl y tolerant of fire. Historically it occurred as the predominant species on sites where mixed severi ty fires killed the thinner barked species. The amolUlt of western lard1 cover type ha s decreased by 72 percent since the mid 1950s (Brown and Chojnacky 1996). It has been replaced Current distribution largely by Douglas-fir and grand fir, species that are more susceptible to fire, drought, insects and disease. throughout the state where ponderosa pine has Western larch has few serious insects and decreased. diseases, and the most significant impacts have Successful fire control during the 20th century come from management practices that favored has increased stand densities in some warm, dry shade tolerant species (Carlson et aI1995) . TI,ese Douglas-fir types and created fuel ladders where include selecti vely logging of the more valLla ble large intense fires may result (Crane and Fischer big larch; lack of regeneration harvesting or fire; 1986). In addition, successful fire control has and a lack of thinning, either mechanical or fire increased the area occupied by Douglas-fir by induced. allowing it to uwade dry sites that were formerly grasslands maintained by fire. TI,ese changes in forest compositi on have Douglas-fir fa vored a nU111ber of na ti ve insects and diseases, defoliating insects, dwarf mistletoes and root rots Douglas-fir is currently the most prevalent (Byler and Zimmer-Grove 1990) . These are forest type in Idaho. It can be fow,d in extensive discussed further in the "issues" section of the pure stands, either even- or LU1even-aged, or in report. ------13 and to harvest stands of lodgepole before they Lodgepole Pine were attacked by the mountain pine beetle. This has created some areas of younger lodgepole Lodgepole pine occupies 2.3 million acres in forests, although the pattern of the forest patches Idaho and grows under a wide range of is much different from what wildfires created in conditions. It can be found in all the provinces the past. except the Intermountain and Great Plains. It The occurrence and spread of dwarf mistletoe occurs in pure or mixed species stands. The in lodgepole pine was limited in the past in some amount of lodgepole pine cover type in Idaho has areas by large stand replacement fires. Fire decreased slightly during recent decades. suppression has allowed the amount of dwarf Fire, mountain pine beetle, and dwarf mistletoe in lodgepole pine to increase. In mistletoe are three important disturbance agents southern Idaho, an estimated 64 percent of all which greatly affect growth and development of lodgepole pine stands contain some level of dwarf lodgepole pine forests (Gara and others 1984). mistletoe infection. (Hoffman and Hobbs 1979). The age of these forests on the whole are greater now than typically in the past, which has provided abundant food for mountain pine Aspen Forest Types beetles. Fire is a principal factor in the establishment Aspen stands are unique from previously and structure of most lodgepole pine forests. discussed shade-intolerant species in two Historically, the frequency of fires varied every 60 important ways: (1) Aspen are a short-lived seral to 500 years and their severity resulted in a diverse species, typically only surviving from 60-120 mosaic of age classes and species mixtures in years. (2) They are really stems originating from Idaho's lodgepole pine forest types (Romme large underground root systems. All of the "trees" 1982). connecting to the same root system are genetic In the Northern Rockies province, severe fires clones of one another. These large root systems, typically have created large expanses of even­ often covering several acres, reproduce by sending aged, pure or mixed species stands of lodgepole up thousands of "seedlings," technically suckers, pine. In the Southern Rockies Province,low­ after the aspen overstory is disturbed. intensity surface fires often have maintained Lack of fire in aspen communities has multi-aged stands in which climax species were allowed conifer species to establish and eventually unable to develop (Lotan and Perry 1983). The dominate these areas. Aging aspen is subject to Middle Rockies have a good representation of damage from a variety of stem and other diseases. both conditions. Fire suppression efforts, FHM data indicate that such damage is common. however, have reduced the diversity of age classes Only 38 percent of the trees examined were free of and forest structure. damage; whereas more than 80 percent of conifers Mountain pine beetle has played and were undamaged. (Appendix A) continues to play an important role in the cycle of Aspen forests appear to be on the decline fire and reinvasion that has maintained lodgepole throughout the Interior West and in portions of pine forests. By periodically killing trees and the Inland Northwest (Bartos and Mitchell 1998; creating large amounts of fuel, the mountain pine Brown 1995). In Idaho, this phenomenon appears beetle enhances the probability that a lodgepole to be most pronounced in the Intermountain, pine stand will be destroyed by fire and will Middle and Southern Rockies Ecoregions. A reoccupy the site before it is succeeded by other recent inventory of tree cover on the Targhee species. For example, between 1975 and 1981, National Forest indicated about a 90 percent millions of lodgepole pine were killed by decrease in aspen since the beginning of this mountain pine beetle in Idaho. After 20 years, century (USDA Forest Service 1995). Succession to most of those dead trees have fallen and created a other species from the lack of fire was the primary "jackstraw" of woody material that represents a cause of aspen decrease (Figure 10). Secondarily, huge amount of fuel and a very high risk of fire. grazing by large numbers of cows or big-game There have been extensive logging activities prevents successful regeneration. in some parts of the state to salvage the dead trees 14 ------Grand Fir Grand fir occurs throughout the lo rthern Rockies and in the no rthern and western parts of the Middle Rockies (Figure 11). It accounts fo r 2.2 million acres of fo rested land in ldaho, a significant increase over the past several de­ cades (Brown and Chojnacky 1.996). Brown and Chojnacky (1996) found that the "spruce-fir" class increased by 177 percent (F igure 11). Data from th e ldaho Panhandle National Forests in the Northern Rockies, suggest a 300 percent Ulcrease (Zack 1997). Causes of the increase incl ude fire suppres­ sion, white pine blister rust, and selecti ve Figure 10. Conifers taking over aspen. harvesting practices that decreased the histori­ ca ll y abundant pines and larch and allowed the shade-tolerant grand fir to increase. On drier grand fir sites, frequent surface fires historically maintained open stands of fire-tolerant ponde­ rosa pine with some Dougla s-fir. On cooler and wetter sites where fires were less frequent, open stands of western white pine, Douglas-fir, western larch and sometimes lodgepole pine occurred. Grand fir now domin ates on many of Figure 11. Grand Fir Distribution these sites.

a. HlstOficai distribution b. Current distribution

Legend o 0Ihet fofwt eov. Types ------15 Grand fi r is highly susceptible to drought, species that will grow in some loca tions. wildfire, and several damagin g insec ts and Whitebark pine, like western white pine, is a diseases. Extensive mortality pe ri od ically fi ve-needle, w hite pine that is very susceptible occ urs from fir eng ra ver beetl e, parti cularly to the introduced white pine blister ru st disease fo llowing drought, or when it is infec ted with (Hoff and Hagle 1990). In the Northern prov­ root rot. It is also impacted by outbreaks of ince, the impact of the rust has been very signifi­ defoli ating insects. In the Northern Rockies and ca nt, but variable in the amolmt of mortality in northeastern Middle Rockies, it is hi ghl y sus­ th e Middle and So uthern Rockies. The ru st is ceptible to root diseases. And the increase in still expanding in the south, however, and dense, often multi-s toried stands of grand fir significant future damage is expected, although also creates a growing risk of large severe fires. the rate of infec ti on is slower because the env i­ ronment for the sp read of the rust is not as conducive as in the north . Stands have also White bark Pine decl ined as a resul t of fi re suppression effo rts and mountain pine beetle attacks (Bartos and Whjtebark pine occurs in hi gh-elevation, Gibson, 1990), w hi ch has all owed subalpine fir cold conditions in both the northern and south­ and Engelnlann spruce to increase on many sites ern parts of the state (Figure 12). Ecologicall y, with the whiteba rk pine. These species ca n whitebark pine is important: its seeds are a continue to grow in the shade of other trees, but val ued wildlife food for birds, squirrels, black the whitebark pine does not tolerate as much and gri zzly bears. Whitebark pine also is shade and over time is replaced (Arno 1986, important in reducing avalanche potential and Kendall and Arno 1990). soil erosion (Frey 1994). It is the only tree

Figure 12. White Bark Pine Distribution

8. HlstOf'lcal dlsb1butlon b. Current distribution

Legend I 0 _ .... P.. c-T,.. o OINt Fof_ eo.,. Typet -- Idaho EOOfIQlOn BI:Iund.w 16

orest health issues are rooted both in planted near Vancouver, British Columbia. their ecological as well as social The disease was first discovered in Idaho in aspects. A forest is a dynamic system, 1927, and then spread rapidly throughout the continually changing in response to western white and whitebark pine forests of the disturbances. Some disturbances help maintain northern Rocky Mountain Region. Spread to native species and historic conditions. Others whitebark pine and limber pine in the central threaten them. Thus, there are limits to which a and southern Rockies has been slower, but the forest can recover from disturbances, especially fungus is now intensifying in those areas also exotic ones. (Smith 1998). Ecological integrity is defined as the forest's Blister rust has had a devastating effect on ability to renew itself, or the ability to withstand western white pine and whitebark pine forests disturbances and recover through time and in the north. Widespread tree killing was across the landscape. If the forest is to have the apparent by the 1940s, and now, after 50 years, potential to meet social needs, including wildlife the forests of western white pine are nearly habitat, clean water and products such as wood gone. Smaller trees were and continue to be and recreation opportunities, then the integrity of the ecosystem must be retained. killed by the rust directly; larger trees were killed by one or more of the following: the rust, The following sections address seven issues mountain pine beetle and/ or logging. facing Idaho's people and their forests: Among the dead and dying western white · Introductions of non-native species pines were a small proportion that were uninfected. Research showed that these trees · Watershed health were genetically resistant to the disease · Homes in and adjacent to wildlands- (Bingham 1983). That resistance became the the "wildland/ development interface" basis for a tree breeding program. Rust resistant · Harvest rates and sustainability trees for outplanting became available in the mid-1970s, and a small portion of white pine's · The role of native insects and disease former range has been replanted. · The role of wildfire and fire management · Biological diversity of Idaho's forests Implications

EXOTIC INTRODUCTIONS In the long term, success in restoring white pines will likely depend on both continued The introduction of foreign plants, animals, integrated management (Hagle et a11989) and and microorganisms is one of the most disrup­ gene conservation. An effective strategy might tive influences on ecosystems. Sometimes a include the following parts: (1) a commitment non-native species will find conditions highly favorable in its new location. With natural to reforestation, mainly by planting and tending enemies left behind, populations expand un­ rust resistant seedlings but also natural regen­ checked until the species becomes a pest. eration. This will require opening up the forest The result can be that non-native species through burning, harvesting or a combination eliminate native plants or animals from an of the two; (2) species and gene conservation, ecosystem, greatly altering how the ecosystem through the maintenance of wild stock that may functions. This is happening in Idaho, where a have resistance and enhancing opportunities for number of invaders have damaged the state's natural regeneration and natural selection; (3) ecology and economy. continued research, tree improvement, and monitoring to assure needed information and White Pine Blister Rust technology is available to future practitioners so they can adapt and improve upon today's White pine blister rust was accidentally efforts. introduced into western North America about 1910 on infected seedlings grown in France and ------17 Choosing not to restore the white pines will Idaho Department of Agriculture). Several of mean the continued expansion of other forest these plant species have particularly onerous types, such as grand fir, hemlock-cedar, spruce­ characteristics, making them ecological and fir and Douglas-fir, and their associated prob­ economic pests and, as such, have been desig­ lems of insect, disease and fire susceptibility. nated as "noxious" by state law. Such plants are moving into forest areas via windblown seeds, domestic and wild animals Balsam Woolly Adelgid and on vehicles and other machinery. They The balsam woolly adelgid, an aphid-like include, but are not limited to, spotted knap­ insect of European origin, was discovered in weed, rush skeletonweed, leafy spurge, Canada northern Idaho in 1983 at one urban site in thistle, cheatgrass, meadow and orange hawk­ Coeur d'Alene, Kootenai County, and five weeds and yellow starthistle. forested sites east of Moscow, Latah County Invasive" exotics" are very effective at (Livingston and Dewey 1983). colonizing disturbed areas where overgrazing, Its Idaho hosts are primarily subalpine fir, timber harvest, road construction, landslides, or and secondarily, grand fir. Since the initial fires have occurred. Some of the species, like the discoveries, the insect has spread to where it hawkweeds, do not need disturbance to invade now covers many drainages of Clearwater, a plant community. Their introduction, estab­ Idaho, Nez Perce, Lewis, Latah, Benewah and lishment and spread is causing rapid changes in Shoshone counties. the succession, species diversity and function of The insect has killed thousands of subalpine many ecosystems. fir, especially in frost pocket-drainage bottoms. Disruption in ecosystems by invasive exotic In these sites we found extensive mortality weeds is considered unhealthy, as these plants within six years of the initial infestation. displace native plants. Changes in plant com­ The insect has also been found infesting and munity composition, diversity and structure can killing subalpine fir in a few high elevation sites adversely affect the quantity and quality of of Clearwater County. Grand fir has been forage for livestock and game animals, erosion infested as well, but there has been relatively of soil, sediment in streams, wildlife habitat, tree little mortality of this host species to date. regeneration, recreation sites and rights-of-way (Duncan 1997, Rice and others 1997). Implications

In some drainages the tree mortality caused Implications by the balsam wooly adelgid is affecting ripar­ Non-native invasive plant introductions ian areas. At those sites where the subalpine fir and spread are occurring more rapidly than our previously provided significant shade, that ability to assess and address them. Weeds do not shade is now gone. respect ownership boundaries; therefore to be The lack of cover could lead to changes in effective, cooperation between neighbors is summer and winter water temperatures, long­ needed. term woody debris recruitment, and to fish Work is being done in some areas where habitat in general. counties, federal and state agencies and private High elevation stands of subalpine fir are individuals have formed weed management also being affected. The loss of trees in these areas to combine and coordinate efforts within sites may have detrimental effects on wildlife, the area. Work by these groups using integrated watershed and recreation resources. pest management practices, such as prevention, Non-Native Invasive Plants early detection and suppression of new invad­ ers, is critical. Also key to success for all land­ Non-native invasive plants currently infest owners is the use of long-term strategies on over 4.7 million acres of land in Idaho, including biocontrol for established weeds. all land-use classifications and ownerships (personal communication with Loall Vance, 18 WATERSHED HEALTH Implications Water originating in forested areas through­ The long-term health of watersheds and the out Idaho is valued for many reasons, from its health of the vegetation in a watershed are use for domestic needs to providing habitat for inextricably linked, they are parts of a whole anadromous fish species. The forested lands ecosystem. An ecosystem that is dynamic with adjacent to streams and rivers serve to collect or without human intervention. Therefore management decisions need to weigh short­ and purify the water, funneling it through a term trade-offs with long-term benefits. Ignor­ network of stream channels into the river sys­ ing watershed health in favor of vegetation tems. health or ignoring vegetation health in favor of The ability of the forests to collect and watershed health are paths doomed to failure purify water is affected by the condition of the over time. Management actions carefully forest and the occurrence of disturbances that designed, executed and monitored, so we change the structure, composition and pattern of continue to learn from our experiences, can forest vegetation. facilitate the attainment of both goals in the long Because of its widespread implications, run. water quality has become a major forest man­ Watersheds are nested, from small to very large, and consideration of activities across these agement issue. In some watersheds riparian scales can facilitate effective scheduling of areas and stream channels have been negatively management treatments, such as prescribed impacted directly by logging, by fires, by road burning, restoring roads no longer needed, building, by dams and by mining. Indirectly, timber harvests, stream improvement projects or these same events occurring on upland areas "resting" a watershed. Communication and may also affect water quality and streamside cooperation across ownership boundaries conditions. within a watershed can enhance achievement of Some relationships between water quality sustainable management for all owners. and condition of the upland vegetation are poorly quantified. However, we know changes WILDLAND INTERFACE in the amount, structure, composition of vegeta­ DEVELOPMENT tion, both live and dead, within a watershed may affect several different aspects of water While natural disturbance events, like fires quality. and insect outbreaks, are common and even Some aspects of water quality affected by healthy for many forests, they present more vegetation include the amount of water flowing difficult situations in developed areas (Rogers out of the watershed, the retention of snowpack, 1996). If forests deteriorate, some people are affected by the aesthetic loss of forest cover and the amount of sediment carried by the water, for other reasons and values for which they the water's temperature and nutrient content. move to a wildland location. Another issue is Variation in these characteristics over time and the fire hazard and threat to life and personal across a watershed is normal and desirable for property presented by abundant dead or dying the proper function of the system. The variation trees. While urban areas throughout the Interior is a function of the amount of plant cover alive West have experienced population booms in the and dead in the form of litter, duff and woody past decade, so have rural areas. Many people debris, successional stage, pattern and structure continue to seek rural locations with nearby of the vegetation across the watershed. Changes recreational opportunities. While some coun­ ties are growing faster than others in Idaho, the in the vegetative condition may be the result of state as a whole has been growing at an esti­ fire, harvest, insect or disease activities, devel­ mated rate of 18 percent per year since 1990. opments including roads, mining or subdivi­ Only a few counties are experiencing low sions. Concerns are raised when the variation of growth rates (Figure 13). Much of the develop­ these attributes exceeds the normal variation. ment that supports this influx of people is in, or It is beyond the scope of this report to adjacent to, forested lands. While some of that assess the health of Idaho's watersheds but it is development is taking place near Idaho's larger important to recognize the links between water­ population centers, there is also a substantial shed health and forest health. amount of new dispersed housing in rural counties. ------19

Figure 13. Figure 14.

VALLEY COUNTY FORESTS AND PRIVATE LANDS Population Growth Estimates: 1990-96

less than 1Q GAI

10·19.9"" • Forost Greater than 20% Water o Non-Iorest o PRIVATE LAND

Implica tions

The issue of the wi ldland in te rface spurs numerous questions. How much of forest lands should society develop fo r residential purposes? Source: Idaho Bureau of Census, 3120, 1997 If houses are built or alread y present, who will take the responsibi li ty of managing sLuToun ding forests to protect human interests? How ca n Va lley County, in the central porti on of the individ ual homeowners reduce the risk to th eir state, is a good exa mple of the growth phenom­ property and lives? enon (Figure 14). The county is estimated to be Where human development is adjacent to expanding at a rate of about 31 percent. Much forested wild lands, more intensive management of the land within the CO Lulty'S borders is both prac ti ces may be necessary to minimize the ri sk fo rested and government owned . About 20 of serious loss of life (F uller 1991). Such prac­ percent of the land base is in p ri va te ownership ti ces incl ude forest thinning and crea ting and, therefore, potentially available for residen­ non fo rested buffers. For instance, removal of ti al development. Nearly all of that develop­ "hazard trees," or trees that are rotten or par­ ment is in close proximity to the surroLmding ti all y dead near human structures, is good forest lands. "preventi ve medicine" against fu ture injury or The problem in terms of fire management is property damage. obvious. The probability of human-ignited fire Fo rest health along th e urban/ rural wild ­ is greater where there are m ore people, and land interface is more th an just a problem for there is an ever-increasing popula ti on in the people. When people move into forested areas, wildland interface. More fire starts in conjunc­ habitat is diminjshed for some animals. Wild tion with dense fo rests and hot or windy animals that remain are often in conflict with weather conditions, increases the possibili ty of humans. Examples include mountain li ons fires ca pabl e of destroying homes and putting preying Oll domestic animals or deer browsing human lives at ri sk. on residential shrubbery. 20 FOREST GROWTH Net growth can be conl pared w ith tree remov­ als to estinlate net change. Overall, net growth \-v as Da ta shows the to tal inventory volume of nea rl y three times tree removals, but there were growing stock on Idaho's timberl and totals 39.6 substantial differences by ownershi p. On NFS billion cubic fee t, an increase of 12 percent be­ lands, the growth was more than fo ur times tween 1952 and 1987. Avera ge net annual growth OTea ter th an the renl ovals; w hereas on otl,er was 816 million cubic feet. Of that gro wing stock, ~w n e r shi ps it was about one and one-h alf times 76 percent is on National Forest System (NFS) grea ter than removals . . lands. O ther fa ctors affec ting forest growth Illdude The volumes of western white pine, western diseases, insects and fire, some more severely at larch and ponderosa pine have decreased. Pon­ times and loca ti ons than others. derosa pine and western white pine, hi storica ll y Overall, net growth appears positive for most the two most important timber species in the species, with some exceptions. On the Boise and state, declined by nearly 4 biJ lion cubic feet Payette Nati onal Forests, mortahty from lllsects, between 1952 and 1987 (O'Laughlin, et al. 1993) . disease and fire exceeded growth for the perIod Ponderosa pine decreased by 40 percent and 1988-1992. western white pine by 60 percent. Mountain pille beetl e was the ca use of exten­ Douglas-fir increased by 15 percent and now sive m ortality of lodgepole pine on the Targhee, composes 31 percent of the total growin g stock Sawtooth, and Ca ribou Na tional Forests during (Fi gure 15) . the 1970s and 1980s. In northern Idaho, mountain An aggregati on of Engelmann spruce, west­ pine beetle in the early part of the century an d . ern larch, western red cedar, and western hem­ later in combination with blister rust ca used major lock increased by 30 percent. Although western losses of western whi te pine. larch is included among the cl ass experiencing an Root disease is extensive in many locations increase, it most likely decreased since the acre­ where white pine and other species were replaced age in larch type decreased. by Douglas-fir and true firs. Timber volumes in infested stands are reduced by about 50 percent.

Figure 15. Growing stock in nonreserved lands (Resource Bulletin. 1988) 15 0 Other r-

~ III 0 National Forest III u.. ]0 - () r- .D ;::l U c: o - r- 5 - r F r- F r- I- 1-1r::=l II iF"' I I o I I I I I I I I I I I I I , , ...... ~ ,-... ~ ~ ... ..:.: ..:.: e ~ ~ "0 ~ !;:: !;:: e e '-' ~ -='-' '-' '-' ~ e e 0 e , .- ;::l "0 ... 0 0 0. .- .- ~ 0 "0 '5. - 0. ... III ~ 0. 0. '"~ e e 0. - - '" 0. ~ ~ '-' E E ~ ..:.: ... ~ ~ ..... e 'Eil 0. "0 ~ ~ -< ... ~ 0 '" ~ 0 ;: ... '"0 .c ~ ..... ,Q 0 Q 0. ~ ... w ... ~ -= -= ,Q ..... ~ ,Q ~ e ~ ~ 0 E ~ CD ;::l "0 ...... "OrJJ e ~ ~ U -l 0 0 ~ ~ -= -l ~ ~ ------21 INSECTS AND DISEASE In sects and pathogens are highl y adapted to particular forest conditions, i.e., species compo­ Disease agents (pathogens) and insects siti on, age, density, and others. So as forests a ffect forests in va rious ways (Haack and Byler change in composition and stru cture, they 1993). They are essential to the fun cti on of become more susceptible to some agents and d ynamic ecosystems: they serve to thin out less susceptible to others. some of the trees, recycl e nutrients, create It, therefore, should not be surprising that habitat and provide food to many wild life some insects and pathogens have become less species. They ca n also negatively affect resource comnlon and S0111€ more common as forests va lu es and ecosystem function. change. Given the current susceptibility of some Thus, th eir effects may be viewed as bene fi ­ stands, the considerable disease and insect cia l or detrimenta l, depending on the manage­ ca used changes and resource impac ts are ex­ ment objecti ves of the owner. Key questi ons pec ted to continue. in volve how insect and pathogen activities affec t the things we va lue, both in the short and long­ Root Disease term. In this report, we will focus on only a few Root diseases are common in the moist na ti ve pathogens and insects in Idaho, specifi­ Douglas-fir, grand fir and high elevation cool ca ll y those having the most significa nt effects on subalpine forests in the Northern Rockies current forest conditions. Province. Several pathogens are in volved, even From the resource perspecti ve, tree mortal­ in the same stand, so it is usual to consider them ity and growth loss can be highly significa nt. as a group. The main hosts are Douglas-fir and The tw o affect timber growth mld reduce desir­ true firs. The pines and western larch ca n be able forest cover in recreation area s. They ca n infected, but are not so readily kill ed (with the present ha za rd s to visitors, reduce the abili ty of exception of annosum root disease in ponderosa forest ca nopi es to intercept snow and prevent pine forests). Root di seases have appa rently excessive runoff, change wildlife habitat and increased significantly over th e past several influence varioLi s other COllll11odities and ameni­ decades, with the several-fold increase in host ti es. abundance. About 2 million acres have been Fire, insects and disease are regulators of estimated to be significa ntly affedted by root forest change. With wildfire suppression, disease (DeNitto 1985). insects, pathogens and humans have become the Permanent plot data indica tes that root major agents of change. In particular, they play diseases commonly kill an average of 2-4 per­ enhanced roles in succession, decomposi ti on cent of the susceptible trees per year. The and nutrient recycling. cumulative effect of this is the removal of most such trees by 80-100 yea rs (Byler and Hagle, unpublished data). In mi xed species stands, Figure 16. Root rot openings. disease has a thinning effect by removi ng susceptible and leaving disease-tolerant species. In stands of susceptible species, the entire stand ca n be killed. Root diseases are va ri able in d istribution, but can have major effects in some areas. For example, a root disease assessment in the Coeur d' Alene Ri ver Ba sin in the Northern Rockies indicated that 35 percent of the basin consisted of Douglas fir or grmld fir cover types wi th root disease (Hagle et al. 1994). Of the infes ted acres, 62 percent were rated as severely affected, meaning more than a 20 percent reduction in ca nopy had occurred. 22 ------Dwarf mistletoes are more widespread and Implications common in Idaho forests today than in the past because of fire suppression efforts and selective Root diseases may cause extensive mortal­ harvesting practices that left infected overstory ity in forests comprised of susceptible species. trees above those being regenerated. Where Losses are often underestimated because it ground fires were once frequent, many mistle­ occurs in a dispersed pattern in an area infested toe-infected trees were often killed because and over a long period of time. Mortality can be large, drooping witches' brooms often carried accelerated by activities that thin the forest but ground fires into the tree crowns. retain susceptible species. The most effective treatment in these situations is one that re­ moves most of the trees and reestablishes resis­ Implications tant species, primarily seral species (Figure 16). Root decay can cause tree failure, which Since dwarf mistletoes reduce the vigor of subsequently can have a significant impact on trees and cause death, in forests where this is other forest elements, such as wildlife habitat undesirable i.e., campgrounds, home develop­ and watershed function. Tree failure can also ments, parks and timber production areas they produce wildfire and safety risk in recreation can be managed to reduce their impact. Meth­ areas. However, these effects have not been well ods include pruning or killing the infected trees, quantified. and managing the forests for a different species Extensive disease can maintain a watershed of tree than the ones that are infected. in an open or semi-open condition of mostly In managing large landscapes where the small trees and shrubs, potentially affecting maintenance of diverse habitat is an objective, it water yield and peak flow. is desirable to have the mistletoe present in a portion of the forest (Taylor 1995). The role of stand replacement fires has been significant in Dwarf Mistletoes affecting the distribution of mistletoe and needs to be considered when management objectives Dwarf mistletoes influence the health of coniferous forests because they reduce the vigor include the desirability of natural processes, of heavily infected trees. The infection eventu­ such as wildernesses and national parks ally kills the affected trees outright or predis­ (Kipfmueller and Baker, 1998). poses them to attack by insects and/ or other pathogens. Dwarf mistletoes are important to various Bark Beetles wildlife species because birds and other animals nest in witches' brooms or use them for resting Bar k beetles are considered the most conse­ and hiding sites (Bull et al. 1997). Therefore, quential insects in western coniferous forests, dwarf mistletoes serve to increase species where they kill millions of trees annually. Most diversity within dwarf mistletoe-infected for­ of this mortality is scattered widely throughout ests. mature forests (Furniss and Carolin 1977). Dwarf mistletoes are widespread through­ However, when conditions are favorable, bark out the forests of Idaho. In southern Idaho, beetle populations can develop into outbreak dwarf mistletoes infest 45 percent of the lodge­ proportions and kill large numbers of trees over pole pine stands, 33 percent of the Douglas-fir large landscapes, as currently occuring in stands and 25 percent of the ponderosa pine northern Idaho with the Douglas-fir bark beetle. stands. In northern Idaho, the most common In general, these outbreaks are initiated in dwarf mistletoe is larch dwarf mistletoe, and trees that are either windthrown or stressed due approximately 40 percent of the western larch to overcrowding, drought, inadequate nutrients, stands are infested. In total, more than 3 million injury, advanced age, or climatic change. Other acres are infested in Idaho (Johnson and biological agents such as root diseases, foliage Hawksworth 1985). diseases, dwarf mistletoes, and defoliating ------23

Implications Figure 17. Bark beetle trends. Among the effects of bark beetl es on forest resou rces are: increased fire hazard due to Trees Killed By Bark Beetles in increases in ava ilable fu els; changes in w ildlife Idaho 1982 - 1997 species composition and distribution through altered habitat conditions to the benefit of some species and the detriment of others; severe Mountain all o1her 250,000 outbreaks also may increase water yields be­ 200,000 cause of reduced transpiration from dead and 150,000 dying trees; reduce timber production and 2,500,000 100,000 value; increase forage production. These 2,000,000 changes can be viewed as desirable or not 1,500,000 50,000 depending upon the objectives of the land­ 1,000,000 o owner. Where landowner objectives warrant reduc­ 1997 ing the risk of bark beetle infestation forests can E!! wes tern pine beelle _ spruce beelle D fir engraver beetle be thinned mechanically or with prescribed fire. . w, balsam bark beetle _ Douglas-fir beetle iii mountain pine beetle In landscapes with more aging, highly suscep­ tible stands than desired, regeneration by harvest or stand replacement fire may be insects also cause tree stress and illay be associ­ appropriate. Creating a variety of age classes ated with bark beetle attack (Steele, et a!. 1996). across a landscape reduces the potential for Beetle mortality contributes snag habitat severe outbreaks by having less suitable host and offers a source of food to some species of available. wildlife. In some in stances, bark beetl es thin the forest. Mountain pine beetle, Douglas-fir beetle, spruce beetle, western pine beetle, and fir Defoliators engraver beetle are among the most important Historically, two native insects-western mortality agents of mature forest in Idaho. They spruce budworm (WSB) and Douglas-fir tu ssock can significantly change forest structure and moth (DFTM)-cause widespread defoliation of composition by reducing the average age, Douglas-fir and grand fir forest types in Idallo. diameter and height of surviving trees. They They periodically reach epidemic proportions, also lower the density of live trees in the forest. causing severe defoli ation of Douglas-fil; true fir They can affect successional changes in forests, and occasionally spruce. prolTIoting succession in some cases, setting it Outbreaks in these insect populations can back in others. occur rapidly, ca using defoliation over hundreds During the past 15 years, several large bark of thousands of acres annually. In Idaho, WSB beetle outbreaks have been recorded in southern outbreaks have lasted up to 10-15 years; DFTM Idaho (Figure 17). Most of these have occurred outbreaks usually collapse after one to two over large forested areas where mature host tree years. species were growing in an overcrowded and These native forest defoliators are major susceptible condition. In some areas, beetle components of the forest ecosystem in which outbreaks reduced that susceptibility by killing they are fOLU1d. They add to the biological a high percentage of the host trees. In other di versity of the system, serve as food for other areas, the risk of bark beetle outbreaks remains aninlals, and function Ln the release and recy­ high. cling of nutrients. Outbreaks of the insects can cause radial 24 cially when other tree stressing factors, such as Undesirable or unsustainable levels of drought, occur in conjunction with defoliation. native insects and diseases are actually an In addition, outbreaks can affect stand indicator of forest composition and structure structure, species composition and stand succes­ that are undesirable or unsustainable. Much of sion (Brookes, et al. 1978; Brookes, et al. 1985). the current composition and structure of Idaho Forest resources affected by these outbreaks forests has agents producing unacceptable include recreation, visual quality, wildlife changes for some landowner objectives, like the habitat and timber. root rots in northern Idaho or multi-storied Western spruce budworm and DFTM stands of Douglas-fir and grand fir that have the populations are currently at low levels in Idaho, potential for unacceptable outbreaks, of spruce causing no discernible defoliation. The last budworm, as examples. Landowners and WSB outbreak peaked in 1986 at nearly 3 mil­ managers have the choice of using various lion acres of defoliation. That outbreak dropped management techniques such as planting trees, sharply by 1988, and no WSB caused defoliation prescribed fire, mechanical treatments like has occurred in Idaho since 1992 (Beckman logging or mechanically thinning the forests to 1996). provide a mix of forest composition and struc­ Similarly, the latest DFTM outbreak oc­ ture that is sustainable. curred during 1990-1992 in southern Idaho, where it caused defoliation on more than 400,000 acres of forested land and resulted in Fire high levels of Douglas-fir and grand fir mortal­ Idaho's forests evolved with and adapted to ity (Weatherby, et al. 1997). fire. All are in some way "fire dependent./I Reduced fire frequencies, the result of suppress­ ing natural fire starts combined with the elimi­ Implications nation of native American burning during much of the current century, have altered forest While WSB and DFTM populations are compositions and structure. currently at low levels, recent monitoring Fire is a normal part of the forest ecosystem shows they may be building up. Forest condi­ and is essential to sustaining forests. It func­ tions over much of the state remain favorable tions to reduce surplus biomass, recycle nutri­ for future outbreaks of these insects. ents, set the stage for regenerating forests and in In general, dense, uneven-aged, mature combination with other disturbance mecha­ stands of Douglas-fir and/ or grand fir are at nisms maintains a diverse forest landscape. high risk to future outbreaks. Particularly Yet, severe stand replacing fires over large vulnerable are those stands growing on warm, areas may be incompatible with our current dry sites. Silvicultural practices, such as pre­ human settlement and uses of the forest. Such scribed fire, timber harvesting, and thinning, large severe fires threaten human lives, build­ can reduce the risk, if they are implemented to ings, air quality, wildlife, wildlife habitat, reduce the composition and structure of suscep­ timber, water quality and quantity, and recre­ tible forest stands. ational opportunities. In addition, when such fires occur on the steep granitic soils of central Idaho, they can cause serious erosion and Implications landslides that further threaten human lives, for Native Insects & Diseases buildings and natural resources. Historically, fire patterns varied greatly in Each of the agents previously described is different locations (Arno 1980). In forests at part of a healthy, functioning ecosystem. When lower elevations and on dry sites at middle they function outside the objectives the land­ elevations where ponderosa pine was once the owner desires or what the ecosystem can sus­ major forest component, fire intervals averaged tain, they can become problematic. 6 to 35 years (Steele et al. 1986; Arno 1988). ------r ) These fi res usuall y burned the un derstory Since 1984, the number of acres burned and maiJltained forests in an open park-li ke annually by forest fires have increased substan­ condition with grassy undergrowth. Here, tiall y in Idaho. (O'Laughlin 1993.) forests were primarily made up of large, widely spaced pine and larch, which had thick bark and Implica tions were fire resistant. Occasionall y th e fires were m ore severe an d would kill much of the forest Unless fire-susceptible conditi ons change, In fo rests at higher eleva ti ons and in moist, \ve ca ll expect similar large fo rest fires to con­ middle elevations, fire in tervals were longer, tillue to occur. Landowners and 111anagers have ranging from 40 to 200 yea rs (A rno 1993). In a number of tools avail able to alter these condi ­ these areas, fire was generall y two types, mi xed tions: severity where it created a mosa ic of forested - Prescribed fi re, both those resulting fro m conditions, in parts of the burned area some fire lightning and human ignitions, are used to resistant trees slI rv.i veci, but the understory and red uce the amount of fuel, prepare sites fo r the thumed barked trees were burned, in oth er regenerati on of new forests, and crea te more portions very little was affected. diverse forest structures, incl ud ing old growth. The fires that kill ed only part of th e forest The result can reduce the level of risk from some are very important in the development of many insects and pathogens and encourage diversity old-growth forests in the moist types (A tkins of wildlife habita t. 1996). The second type of fire at these higher -Timber harvests can be designed to accom­ elevations \,vas stand replacemen t, in which plish similar results as p rescribed fires. The use essentially all th e trees were killed. In the of harvests in com biIlation with fire ca n be very Northern Rockies, stand replacement fires effec ti ve in changing th e pattern of vegetation commonl y occ urred in western white pine across the landscape to m ore desirable condi­ stands on the average every 150-200 years (Zack tions. Fig ure 18 shows an area that was thinned and Morgan draft). These were often in hot d ry pri or to a wildfire and how it changed the years or fires driven by strong wind events or pattern of the fire's behavior. both . However, many decades of fire prevention, Figure 18. Boise National Forest. fire suppression, and timber harvesting have changed the fire regim es throughout the west­ ern Uni ted States, including Idaho. Our sup­ pression efforts have been, until recently at least, quite successful. There is growing concern that we are be­ coming less successful in our suppression efforts, as fuels continue to accumulate in wlburned and otherwise unmanaged parts of the landscape. Furthermore, many now question the ecological desirability of suppressin g all fires, especially surface and mixed severity fires. Many forested areas now ha ve high fuels, given the accumulation of trees and dead wood in the fo rest from decades of fire suppression, The area on NFS lands currently being and are consid ered at risk of severe wildfire. burned or harvested to p rovide for regeneration When lighhling storms igni te multiple fires in remains below that needed to m aintain seral dry weather cycles control becomes ex tremely fire-dependent species. difficult and expensive and can cover large Negative effects of burning include the risk areas. In the dry forest types, fires can be more the fire could escape, produce smoke that can severe than in the past. adversely affect human health, and ad versely impact th e aesth etics of th e airsheds. Harvest­ ing generally requires some road building, 26 which increases the potential for increased diversity through the loss of plant and animal sedimentation and presence of potential barriers communities which thrive in these forest types. to fish movement. To mitigate the negative impacts of fire and harvesting, care in design and implementation of management activities is needed to sustain Implications proper functioning of the ecosystem. Several tactics are used to maintain biodiversity: (1) Rare plants or animals are Biodiversity listed as threatened or endangered and plans are developed to enhance their habitat. (2) In Idaho, threatened populations of a few Habitat conservation areas are established to prominent species, such as the grizzly bear or maintain viable populations at various scales. woodland caribou, serve to highlight the larger (3) A variety of forest types and structures issues of species diversity. Biodiversity may be across a landscape are maintained. This last viewed as a subset of forest health known as strategy, in conjunction to a lesser extent with "habitat health." the previous two, is aimed more at sustaining Sustained healthy habitats for wildlife, plant and animal communities, rather than vascular plants, and non-vascular plants (e.g., individual species (Merrill and others 1995). lichens, fungi, and bryophytes) is an important Tactics 1 and 2 are referred to as "fine filter" measure of all plant communities, including approaches to conservation of diversity. The forests. Biodiversity is, therefore, a critical third is called a "coarse filter" approach, de­ forest health issue. However, it remains a signed to provide a whole range of habitat difficult element to measure. condi tions to sustain most species. In Idaho, broad-scale species diversity has The fine and coarse filter techniques are best been most affected by human interventions in used in combination, since funds and knowl­ disturbance regimes, such as where fire suppres­ edge are insufficient to manage species solely sion and some timber harvest patterns and using the fine filter approach (Hunter 1990). prescriptions are evident. Exotic plant, disease, Reliance only on the fine filter approach also and insect introductions also influence species may result in management that is in conflict diversity. with the coarse filter approach and vice versa. Many of these interventions and introduc­ tions have been discussed in previous sections of this report. Often these components work together to limit the amount and diversity of native species populations. In terms of forest landscapes, native diver­ sity is best maintained with a variety of forest type and stand structure conditions. While old­ growth forest may support a greater diversity of species at one location, landscape diversity is best supported by a strategy that provides a mixture of age conditions from young to old (Halpern and Spies 1995). The challenge is maintaining the mix of young, mid-age, and old forests which supports diversity across the entire landscape. Previous management practices in this region have affected successional stages overall by reducing the percentages of young and old stands, while increasing the percentage of mid­ age forests (Langner and Flather 1994). Further­ more, great reductions in some forest types, such as western white pine, aspen, and ponde­ rosa pine, will likely result in reduced regional ------27 Management Implications

he iSSlles identified in this report are a product of nlonitoring, research and management ex peri Tence. For a land manager or owner, what can be done to address those issues? How can the ecologic integrity of forests be restored so that the lal1d can meet individual and diverse objectives? The loss of integrity can be traced largely to three actions: 1) Addition of foreign agents. Exotic plants, pathogens, insects and other agents can profoundly affect ecosystems. Examples in Idaho include white pine blister ru st and a grovving nLLlnber of noxiolls weeds. These agents now threaten a number of native species. 2) Withholding fire. Fire is a key process in the western "fire adapted forests". Without fire, forests continue to change with pathogens and insects playing a larger and different role. Fire prepares the site for regeneration of the shade intolerant species. The trend is loss of these species that were historically most abun­ dant, and increase in medium-sized forests of shade tolerant species. [t appears that forests reduce the risk of wildfire. We have since are becoming less diverse and more homoge­ learned this can deplete some nutrients and neous. remove habitat for some animals important to 3) Direct influence. Humans have di­ the proper function of a healthy forest. Adjust­ rectly affected forests by harvesting, mining, ing management activities to respond to new road building and other forms of development. information and knowledge when things go Harvesting, especially selective harvest of hi gh­ wrong can minimize and mitigate the effects of valu e trees, has decreased the amount of shade­ unanticipated consequences. Such response is intolerant pines and western larch, and reduced referred to as "adaptive management." the amount of older age forests. - Public values changed. Practices that were tolerated, even seen as desirable, are now These changes and others occurred for considered wlacceptable. Also, there is no several reasons: public consensus on what values should be - Information was lacking on how forests used to manage forests. Given that situation, tlle would respond to these human influences. wisest management policy might be one which Monitoring and research during the past several maintains options where possible. decades has put us in a better position to predict It is clear that some changes in manage­ the effects of our actions. ment policies and practices will be needed. - Some management practices instituted Inaction or passive management will allow for desirable goals ended up prod ucing other some of the problems to worsen. Managment actions inlplemented using our understanding unforseen, undesirable results. An example, of forest functions, like fire regimes, seems to be was the past practice of removing or burning a prudent course to pursue (Quigley and others most of the wood y debris after a harvest to 1998). 28 ------Much remains to be learned, but strategies and to protect watersheds from flooding and are being developed that offer promise (Everett from sediment produced after fires had oc­ and Baumgartner 1995; Sampson and Adams curred. Large wilderness and roadless areas 1994). Each particular landscape has a different that people think of as pristine have been influ­ solution or combination of solutions depending enced by this policy as well. on the type and number of health problems that It is clear our past land use practices have exist and the values for which the land is man­ brought significant changes to Idaho's forests. aged. If we assume that it is desirable to maintain Solutions to these health problems involve a native tree species and, at a minimum, represen­ combination of management activities: (1) tative areas with historic stand structures, we prevention, to keep exotic species from becom­ must conclude past actions have had a negative effect on achieving this objective. Several tree ing established or spreading farther, to prevent species, such as western white pine, aspen and wildfire through fuels reduction, to prevent ponderosa pine are much reduced from what disease and insect damage through hazard they were historically, especially in large size reduction; (2) integrated management, to deal classes. with exotic agents now firmly established, to On the other hand, some forms of manage­ reestablish appropriate levels and functions of ment have replaced or complemented the stand native insects and diseases; (3) suppression, of replacement or thinning effects of wildfire. For fire, diseases and insects when the alternative is example, commercial thinning has reduced unacceptable; (4) restoration, of damaged densities in ponderosa pine forests. Logging, watersheds, of fire in the ecosystem, of tree followed by planting rust-resistant western species and structures that have become scarce; white pine, provides the potential to restore that (5) monitoring, to track broad vegetation trends, species in significant amounts. to evaluate the effectiveness of treatments, make While wildfire suppression was successful adaptations as we contine to learn, and to detect in reducing the loss of timber and human life, it emerging problems. allowed stand densities to increase and succes­ All of these elements that address forest sional change to occur favoring shade-tolerant health problems require using our current forests. understanding of how ecosystems work and Current information and modeling projec­ what objectives are to be achieved. Many of tions indicate that changes in forest types and these forest health issues have developed over a structures will continue under current manage­ period of decades and will require commitment ment practices. Intermediate and regeneration to long-term activities or projects to restore harvesting and prescribed fire are increasingly forest health. Other issues can be addressed in used to reduce stand densities, to reduce the relatively short periods of time. probability of severe fires, and to favor shade­ intolerant species. To reverse the downward trend of western Summary white pine, western larch, and ponderosa pine forest types will require active management (Hann and others 1998). It would include more Our goal is to provide information on the actions that regenerate a new forest such as condition of Idaho's forests so that people can prescribed fire or logging. make informed management decisions. Our We have learned much about our forests, intent is to provide pertinent data that can be about their response to our actions, and about used to develop public policy and guide man­ the ways in which they continue to change with agement programs to restore and maintain and without active management. This informa­ forest health conditions consistent with societal tion can be used in the formulation of policies and landowner values. and prescriptions to make treatments more Some of Idaho's forests have been altered predictable and effective than in the past. dramatically by a century of intensive use, such Pathogens, insects, and, periodically, wild­ as mining, conversion to agriculture and log­ fire continue to influence managed and ging. Other human activities, including fire unmanaged forests alike. The management suppression and the introduction of non-native challenge is to judiciously influence the direc­ species, also have produced profound changes. tion of change toward maintenance of desired Aggressive fire suppression was instituted conditions based on landowner objectives. to protect the value of forests for commodities ------29 . The forest health monitoring program with tions and amounts, is incompatible with current Its long-term focus, can help detect and evaluate human settlement and uses of the forest. There changes in our forests and the effectiveness of are risks to people and property, and the aes­ current management policies. That information thetics effects of smoke and the effects on can t~en b~ used by owners, managers and human health remain issues to be addressed. p~~hc pohcy makers to identify opportunities to Thus we face choices. Where and when mItIgate undesirable changes. will we use fire to accomplish ecological or resource objectives? Can we accept the risks and undesirable effects associated with its use? Where will we use harvesting or other forms of Summary management to replace the lost function of fire in regenerating with shade-intolerant species? Watersheds, which have been impacted by Some forest health issues offer clear man­ human activities, will continue to be a key agement alternatives, while others do not. element in maintaining forest health. A better Although the problem of introduced pests is understanding is needed about the relationship severe, there are remedies available to us. of vegetative conditions and water quality. We While additional introductions may be also need to use what information is available to inevitable, given modern travel and trade, many develop strategies that will bring long-term pests can be prevented or deferred through health to both watersheds and forests. Active quarantine and other measures. Agents that restoration is needed for both, if they are to have become firmly established can be dealt provide their potential benefits. ,:ith using integrated pest management prac­ Human development in the wildland tIces. interface present especially sensitive manage­ In the case of white pine blister rust, restora­ ment problems. Wildfires can lead to losses of tion includes gene conservation, continuing to property and human life. Insects and pathogens reforest with rust-resistant and potentially can cause changes that make forests less desir­ resistant white pines, monitoring their perfor­ able or transform trees into safety hazards. mance, and maintaining support of research . Problems in the wildland interface will only and tree improvement. Increase as development accelerates in many The types of forest communities present in parts of the state. Outstanding issues for resi­ Idaho have changed significantly during this dents involve personal values, personal safety, century. The decrease in the amount of western and personal property. In part, acceptable white pine, ponderosa pine, western larch, solutions can only be found when individuals aspen, and whitebark pine is profound evidence and communities in the urbani forest interface of these changes. Insects and pathogens have and forest managers explore the issues together. ~lways been important sources of forest dynam­ However, individual landowners can take ICS, however they have become the primary actions to protect life and property from de­ source where fire has been excluded and no ~truction by fire, insects, or pathogens by chang­ other management treatments have been substi­ Ing the density and species mixture through tuted. The effects of insects and pathogens on prudent harvesting or burning. forest composition and structure is very differ­ Ma.intaining biodiversity offers no easy ent than fire (Byler and others 1996,). The res?lutIon because any action, including no insects and pathogens accelerate forest succes­ actIon, can produce both positive effects for sion towards shade tolerant, shorter-lived some species and negative results for others. species, where fire usually favors the establish­ Efforts to conserve individual species will ment of the intolerant, long-lived species, listed continue. But it also appears prudent to in­ above (Hann and others 1998). clude, as a broad objective, the maintenance or Formulating the proper role of fire to restore restoration of representative forest types and and maintain forest health will continue to s~ructures on Idaho's landscape that can pro­ evolve. Fire is essential to sustaining forests as VIde for countless other species. we know them, yet fire, at least in some loca- 30

Conclusion

In taking a broad view of the evolution of landowners and society playa role. With shifts Idaho's forests, we find that major changes have over the past few years in public values from a occurred during the past century. These largely consumptive use of forests to a greater changes have significant implications for forest emphasis on other values, it follows that desired health and sustainable productivity of goods forest conditions should reflect that change. and services we expect from our public and The following questions apply to individual, private forests. corporate and public landowners. What key values do we want our forests to serve? What We conclude with three points: kinds of forests do we want to leave for future Forests change whether we intend them generations? What combinations and arrange­ to or not. Our actions will be more effective if ments of forest types and structures can best we better understand and anticipate those provide for present and future needs? What can changes and consider them in our management be accomplished ecologically, economically and strategies designed to reach desired conditions. politically to achieve and maintain desired forest Humans will continue to impact Idaho's conditions? When we reach some agreement or accom­ forests, for better or worse. Forest managers modation on what conditions are desired, we and individual landowners will have to resolve can begin to make progress in formulating long­ what level of change is acceptable to provide a term policies and strategies for achieving those future supply of goods and services and safe­ guard forest health. ends. We should consider the implications of the current vegetation trends on those elements we value from Idaho's forests, so we can formu­ late our actions to produce desired conditions. Much of the forest health debate to date has focused on "tradeoffs"-timber versus wildlife, roads versus water, etc. We have seen, however, that there can be common ground among seg­ ments of the public. There are trends that demonstrate undesirable or "unhealthy" condi­ tions for several types of resources. We think there can be actions taken that benefit a variety of values, whether we are considering private land or publicly owned land. The first step to achieve a desired condition is to define it. And in that determination, 31

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Furniss, R.L. and Carolin, V.M. 1977. Western Hoff, R. and Hagle, S. 1990. Diseases of forest insects. Miscellaneous Publication No. 1339. whitebark pine with special emphasis on white pine U.s. Department of Agriculture, Forest Service. 654 blister rust. In, Schmidt, W.C. and McDonald, K.J., p. compilers. Proceedings-Symposium on whitebark pine ecosystems: ecology and management of a high­ Gara, R.I.; Little, W.R.; Aggee, J .K.; Geiszler, mountain resource. p 179-190. D.R.; Stuart, J.D.; and Driver, C.H. 1984. Influence of fire, fungi and mountain pine beetles on develop­ Johnson, D.W. and Hawksworth, EG. 1985. ment of a lodgepole pine forest in south-central Dwarf mistletoes: candidates for control through Oregon. In: Lodgepole Pine: The Species and Man­ cultural management. In, Loomis, R.C., Tucker, agement, Proceedings, May 8-10, 1984 Spokane, WA. Susan, and Hofaker, T.H. Insect and disease condi­ tions in the United States 1979-1983. USDA Forest Haack, R.A and J.W. Byler. 1993. Insects and Service GTR WO-46. pathogens: regulators of forest ecosystems. J. Forestry 91(9), p 32-37. Kolb, T.E., Wagner, M.R., and Covington, W.W. 1994. Concepts of forest health: utilitarian and Hagle, S.K., McDonald, G.I. and Norby, E.A. ecosystems perspectives. J. Forestry, 92(7): 10-15. 1989. White pine blister rust in Northern Idaho and Kendall, K.C. and Amo, SE 1990. Simulating 33 disturbances and conifer succession in whitebark pine forests. In: Proceedings-Symposium on 'Romme, W. 1982. Fire and landscape diversity Whitebark Pine Ecosystems: Ecology and Manage­ in subalpine forests of Yellowstone N.P. Ecological ment of a High-Mountain Resource" Intermountain Monographs. 52(2):199-221. Research Station, Gen. Tech. Rept. INT-270, p. 264- 273. Sampson, R.N. and D.L. Adams, eds.1994. Assessing Forest Ecosystem Health in the Inland Kipfmueller, K.E and Baker, W.L. 1998. Fires West. Food Products Press, NY. 461 p. and dwarf mistletoe in a rocky mountain lodgepole pine ecosystem. Forest Ecology and Management. Smith,J. and J. Hoffman. 1998. Status of white 4345. pine blister rust in intermountain region white pines. USDA Forest Service. Report No. R4-98-02. 24 p. Langner, L.L. and Flather, C.H. 1994. Biological diversity: status and trends in the United States. Steele, R.; Arno, S.E; and Geier-Hayes, K. USDA Forest Service, Rocky Mountain Forest and 1986. Wildfire patterns change in central Idaho's Range Experiment Station, Fort Collins, Colorado. ponderosa pine-Douglas-fir forest. Western Journal General Tech. Report RM-244. of Applied Forestry 1:16-18.

Livingston, R. L.; Dewey, J. 1983. Balsam Steele, Robert; Williams, Ralph E.; Weatherby, woolly aphid. Report of an Idaho infestation. Idaho Julie C.; Reinhardt, Elizabeth D.; Hoffman, James Department of Lands Report No. 83-1. 9 p. T.; and Thier, R.W. 1996. Stand hazard rating for central Idaho forests. General Technical Report INT­ Lotan, J.E. and Perry, D.A. 1983. Ecology and GTR-332. Ogden, UT: U.s. Department of Agricul­ regeneration of lodgepole pine. Agriculture Hand­ ture, Forest Service, Intermountain Forest and Range book No. 606. U.s. Department of Agriculture, Forest Experiment Station. 29 p. Service. Washington, DC. 51 p. Taylor, J.E. 1995. Western larch dwarf mistletoe Merrill, T.; Wright, R.G. and Scott, J.M. 1995. and ecosystem managment in proceedings: Ecology Using ecological criteria to evaluate wilderness and Mangement of Larix Forests: A Look Ahead. planning options in Idaho. Environmental Manage­ USDA Forest Service, Intermountain Research ment, Vol. 19, no. 6. p.815-825. Station, General Technical Report, GTR-INT-319.

Q'Laughlin, J.; McCracken, J.G.; Adams, D.L.; USDA Forest Service, Targhee National Bunting, S.C.; Blatner, K.A.; and, Keegan, C. E. III. Forest. 1995. Camas Creek watershed landscape 1993. Forest Health Conditions in Idaho. Idaho analysis: a look at the changes in the ecology of the Forest, Wildlife and Range Experiment Station, Camas Creek watershed over time (draft report). University of Idaho. Report No. 11. 244 p. Weatherby, Julie C.; Barbouletos, Thomas; Quigley, T.M.; Haynes, R.W.; Hann, W.J.; Lee, Gardner, Brian R.; and Mocettini, Philip. 1997. A D.C.; Holthausen, R.S.; Gravenmier, R.A. 1998. follow-up biological evaluation of the Douglas-fir Using Ecoregion Assessment for Integrated Policy tussock moth outbreak in southern Idaho. Report Analysis. JOF Volume 96:10 p. 33-38. No. R4-97-01. Ogden, UT; USDA Forest Health Protection; 14 p. Resource Bulletin. 1988. Ogden, UT: U.S. Department of Agriculture, Forest Service, Inter­ Wells, C.G.; Campbell, R.E.; DeBano, L.E; and mountain Research Station INT-RB-88. 63p. others. 1979. Effects of fire on soil: a state-of-knowl­ edge review. GTR-WO-7. Washington D.C. USDA Rice, Peter M.; J. Christopher Toney; Donald J Forest Service. 34p. Bedunah and Clinton E. Carlson. 1997. Plant community diversity and growth form responses to Zack, A.C. and Morgan, Penelope. 1994. Fire herbicide applications for control of Centaurea history on the Idaho Panhandle National Forest, maculosa, Journal of Applied Ecology. 24, 1397--1412. Review draft, March 22, 1994.44 p.

Rogers, Paul. 1996. Disturbance ecology and Zack, A.C. 1997. Personal communication. forest management: a review of the literature. U.S. Analysis for Couer d' Alene Basin. File on Idaho Department of Agriculture, Forest Service. Generat Panhandle National Forest. Technical Report INT-GTR-336.16 p.

------Al Appendix A different species vary widely. This disparity may SUMMARY OF THE 1996 FHM PLOT be attributed largel y to their different reproduc­ SURVEYS ti ve strategies. For instance, subalpine fir pro­ duces hWldreds of seedlings in ord er that a few The two graphs below describe the variety may survive. Ho wever, ill subsequent yea rs thi s and amount of species tallied in th e forested initial density of regeneration may be thinJled overstory and understory (Figure Al and Fi gure substantiall y due to limited light and water A2). resources. Although ponderosa pines produce A review of the total mature tree tally fewer seedlings than do firs, th e pines have shows the predominance of shade tolerant better surviva l rates due largely to completely species in Idaho, w ith the exception of lodge­ different reproductive strategies. pole pine. TI,is data is consistent wi th Brown In addition to the tree tall y, each mature li ve and Chojnacky (1996) and other information tree was sampled for current cro wn conditions. presented elsewhere in this report Visual crown assessments are made to deter­ In terms of regeneration, the large amolLnt min e changes in crown conditions resultin g of Rocky Mountain maple is probably due to the from a variety of causa I agents. Long-term prominent growth form this species exhibits m onitoring of crown conditions, especiall y near (Figure A2) . Sap lings and seedlings compose point sources of pollution, are good indica tors of most of th e total tall y beca use maples in this general forest conditions. Visual Crown Ratings location may grow as multi-stemmed "shrub­ (VCR) consist of estimates of crown di eback, like" fo rms for decades before they become tree crown density, and foliage transparency. Fi g­ size. ures A3, A4, and AS depict the current crown In terms of age, Roc ky Mountain maples conditions ac ross all plots in th e state. The are not true seedlings, although they are catego­ foll owing paragraphs explain th ese readings in ri zed as such because of their size. Also, note more detail. Future readings of crown va ri ables that the ra ti os between sa plings and seedlings of can be compared to current va lu es to look for

Figure AI. Mature Trees Sampled in Idaho ROCk~ J1)t~ juniper ­ ~ou taln emlOck - vf~~l'ernC~h~t~W~9gg :: ~. WhltebarK In~ ­ P.aper ircn - ~ wes1~~~~JrRb~~ :: ~ Pondero ~lne - = Curlleaf mt'br~)o ~n~ :: ::: estern .. c w~stern nemloc uaKlng aspen Eno emann .pruce western r~d!:ed~r Grand Ir Subalpine Ir Lod~pole pille LJoug las fir o 200 400 600 800 1000 Number of Sample Trees

• Live Trees Standing Dead Trees

* M;'lture Trees an~ those greater than 5.0 inches diameter at breast height or root co llar. A2 ------

Figure A2. Regeneration Sampled in Idaho ROCk~.(3l61i'faW~c?J = ~~Ite ' flwuce = M X'lesY~~~'1~:t'fr oun ~p€l¥J~~ =::l Curlleaf @1tndlFnilr~ =~ WR~~slle - ~

n~ m~nn sJlruce W elite~~nob1R~nffdl~ Ke cecar LO ge~rerPcJ~ Doua'as- Ir RocklLmtnlmap ~UDa prne Ir , o 100 200 300 400 500 600 700 800 Number of Sample Trees

o Saplings o Seedlings

shifts in crown cond itions by species, or by overall tree populati on over time. Dieback is a measure of th e percent of Figure A3. the tree crown that has died from the branch ti ps inward, toward the center of Crown Dieback the crown. From Figure A3, it is cl ear that most Idaho trees have very li ttle d ieback. 2000 ,.~------In fact, very few trees (1.6 percent state­

wide) have dieback in greater than 25 00 l ~o - I I------percent of their crown. Hardwoods ill showed a ma rkedly higher di eback rate >=- than the overall dieback, having 9 percent -o 1000 of trees with grea ter than 25 percent die­ back, however, the sa mple size for hard­ ! Z" 500 +11-1------wood trees was much sma ll er and therefore a little less reli abl e. Fi gure A4 depicts the curren t state of o . .. ~ ....~ --r''"T'-' , ' ""1"",-iii I I ....,.--r--r..,.....,. foli age transparency on FHM plots in o 5 10 1520 2S 3035 40 45 so 55 60 65707580 85 90 9 5 99 Idaho. Transparency is the percent of li ght Percenl Dieback that passes through the foliated porti on of o Hard\... ood s • Soflwoo ds • All Trees the crown, excluding tree branches and mai n stems. A tree with a ra ti ng of "0" or "5" percent transparency all ows ei ther no light, or very little light, to pass through the leaves to the fo rest floor. In general, when trees are unhealthy their crowns begin to thin out, allowing more light to pass through. The bar graph of foli age trans­ parency, similar to crown dieback, is highly skewed to th e lower percent values. In A3

Figure A4. Foliage Transparency 1400

1200

1000 e'"ell I- BOO ...a

~ I» 600 .c E ::J 400 Z 200 ,/I .. 0 ,- ,- o 5 10 15 20 25 30 35 40 45 50 55 60 65 70 7 5 ao 85 90 9 5 99 Percent Tra nsparency

o Hardwoods II Soltwoods All Trees terms of all trees, only 2.7 percent have ties for hardwoods are slightly lower, overall, transparency ratings of more than 25 percent. than those of softwoods, although the sample Hard woods and softwoods have received size for hardwoods in Idaho is much sm all er. Of about the same transparency ratings that particular concern iJ1 future readings will be were greater than 25 percent of the crown (2.9 movementsaway from the middle of t11is graph and 2,6, respecti vely). by any speCies groups. Currently, 94 percent of . Crown density is determined by estimat- all trees are from 25-75 percent density ratings. mg the percent Crown area that blocks light A greater percentage of hardwoods are below 25 from passmg th rough. This rating does percent, while a grea ter percentage of softwoods mclude wood y parts of the tree, so this is not are over 75 p ercent. Low density crowns may a reflection, or subtracti on, of foliage trans­ signal declmes m growth from a variety of parency. As seen in Figure 24, crown densi- ca usal agents. Ve ry dense trees may be un­ healthy as well. Fo r example, many conifer species "broom up" as a result of mistletoe Figure AS. infec tion, Crown Den sity 500

400

'"Q) ~ 300 "0 ~ .2l 200 - E ::J Z 100

il JO a o j o 5 10 15 20 25303540 4550 5560 65 70758085 90 95 99 Percent Crown Density

o Hardwoods • Softwoods CJ All Trees A4------

Distribution of forest land (0/0 forested plots in Idaho by forest type and plot-level categories, 1996.

Stand-level category % of plots Stand-level category % of plots

Forest Type Group Seedlings / Acre

Douglas Fir 32.33 0-999 65.92

Ponderosa Pine 3.53 1000 - 1999 17.03

Lodgepole Pine 13.96 2000 - 2999 8.33

Spruce/Fir 15.59 3000 - 3999 2.08

Grand Fir /White Fir 14.69 4000 - 4999 1.51

Spruce 1.51 5000 - 5999 1.51

5-Needle Pines 0.76 6000+ 3.60

Mise. Sfwd. Timber. 6.80

Aspen 3.12 Snags/ Acre

Misc. Hrwd. Timber. 0.76 0 30.64

Piny on-Juniper 3.21 1- 24 44.95

Misc. Hrwd. W dId. 2.29 25 - 49 14.83

Other Timberland 1.14 50 -74 5.79

75 - 99 2.27

Stand Origin 100+ 1.51

Natural 97.64

Planted 2.36 Basal Area/ Acre

0-39 24.72

Stand Size 40 -79 19.06

Sawtimber 66.48 80 -119 20.83

Poletimber 23.48 120 - 159 13.13

Seedling/Sapling 8.60 160+ 22.25

Non-Stocked 1.45

Stand Age

0-50 20.85

51 -100 50.59

101- 150 23.72

151 - 200 4.03

201 - 250 0.81 q ~~ ~ !2 ue.; Distribution of damage types 00 g by species for trees & , ? e.;" 90 & :? ;? ~ & '$' ~~ (5 dbh and larger) o'D' ~ 0 8 u'D' >::--0 b. c.;;& "8 a ~ ",eJ 'tY ~ o 0 s~...... c:; on Idaho Plots. ::? ~ 0 C, c$.e.; ;: ? .;$' ;:y.c:;r --0 ~ ~ --0 0' & .c, --0 90 ~..... '1r~ ~ ~o ~ ~ ~ ~ q Cf'$' ~ 'D' ~ e.;" e; " 0;o if q.oS'~ §' ue.; .c,U a ~ e.;c, rtf$' ~ .8 Cf O -:P e.;" ~ ~ ~ S' lO q q'" $ ~ ~¢J q $ ."Yih' --&~..... --0' 0"-.,; fx: U u0" oq ~ ~' Softwoods

Douglas-fir 695 (87) 126 4 32 8 6 1 0 0 45 12 18 0 0

Ponderosa Pine 41 (87) 8 0 2 1 0 0 0 0 2 1 1 1 0

Lodgepole Pine 561 (74) 237 28 43 81 3 1 2 0 31 4 32 11 1

Subalpine Fir 366 (84) 86 11 22 14 2 0 1 1 25 5 4 1 0

Englemann Spruce 119 (88) 20 1 3 3 5 0 0 0 6 2 0 0 0

Other Softwoods 663 (88) 100 3 39 12 1 1 0 2 30 4 0 7 1

Softwood Woodland 83 (86) 17 0 9 1 1 0 0 0 1 1 3 1 0

Subtotal, Softwoods 2528 (83) 594 47 150 120 18 3 3 3 140 29 58 21 2

Hardwoods

Aspen 52 (38) 107 48 32 7 3 0 0 0 11 6 0 0 0

Cottonwood 9 (100) 0 0 0 0 0 0 0 0 0 0 0 0 0

Other Hardwoods 13 (38) 9 0 2 1 0 0 0 0 4 2 0 0 0

Hardwood Woodland 74 (67) 48 0 12 3 0 1 0 0 3 28 0 0 1

Subtotal, Hardwoods 148 (54) 164 48 46 11 3 1 0 0 18 36 0 0 1

Totals 2676 (81) 758 95 196 131 21 4 3 3 158 65 58 21 3

V\> * # of damages recorded may include multiple damages, up to 3, for individual trees Bl ------

For more information related to forest health contact:

State Forester Station Director Idaho Department of State Lands Rocky Mountain Research Station P.O. Box 83720 240 W. Prospect Road Boise,ID 83720-0050 Fort Collins, CO 80526-2098 . (208) 334-0200 (970) 498-1126

Regional Forester Regional Forester Intermountain Region Northern Region Federal Building Federal Building 324 25th St. 200 E. Broadway Ogden, UT 84401 PO. Box 7669 (801) 625-5605 Missoula, MT 59807 (406) 329-3511

Authors' Addresses:

Dave Atkins Ladd Livingston Forest Health Monitoring Idaho Department of Lands Federal Building PO. Box 670 200 E. Broadway Coeur d'Alene, ID 83814 P.O. Box 7669 (208) 769-1528 Missoula, MT 59807 (406) 329-3134 Paul Rogers Rocky Mountain Research Station Dayle Bennett 324 25th Stret Forest Health Protection Ogden, UT 84401 1750 Front Street (801) 625-5330 Boise,ID 83702 (208) 373-4220

Jim Byler Forest Health Protection 3815 Schreiber Way Coeur d'Alene, ID 83814-1630 (208) 765-7342