Effects of understorey vegetation on tree establishment and growth in a silvopastoral system in northern Greece

The interaction between understorey plants and trees in a young silvopastoral system was studied in a sub-humid Mediterranean environment with cold winters in northern Greece. The experimental design was a split-split plot with three replications and included: three understorey treatments (grass, legume and control), two tree species (Acer pseudoplatanus and Pinus sylvestris) and two spacings (2.5×2.5 m and 3.5×3.5 m). The competition between herbaceous plants and trees resulted in significant differentiation in tree growth while their spacing did not produce any significant differences. The influence of trees on herbage yield either by plant species or spacing was not significant. During the early stages of establishment, a significant positive correlation was observed between sycamore growth and soil moisture, leaf weight, leaf area and leaf number as well as nitrogen and potassium concentration in leaves. Six years after planting the height increase of the sycamore trees was largest in the control treatment (415%), lowest in the grass treatment (134%) and intermediate (192%) in the legume treatment. Much higher was the increase obtained for the diameter, 161%, 207% and 536% respectively for the grass, legume and control treatments. The Scots pine trees grew faster than sycamore over the course of the experiment. Height increased by 397%, 351% and 400% and diameter by 518%, 443% and 683% respectively for the grass, legume and control treatments. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of wood-ash application on potential carbon and nitrogen mineralisation at two forest sites with different tree species,climate and N status

In the future it may become common practice to return wood-ash to forest ecosystems in order to replenish nutrients removed when brash has been extracted as a source of bioenergy. Wood-ash contains most of the nutrients that are present in the brash before its removal and burning, with the important exception of nitrogen (N). In the present paper we report measurements of CO₂ emissions and net N mineralisation in the humus layer and the upper 5 cm of mineral soil 12 years after the application of wood-ash to two study sites, representing different tree species, climatic conditions and N deposition histories. We hypothesized that application of wood-ash would increase both carbon (C) and net N mineralisation rates at Torup, an N-rich site with Norway spruce (Picea abies (L.) Karst.) in the south, whereas the net N mineralisation rates would not be affected at Vindeln, an N-poor site with Scots pine (Pinus sylvestris L.) in the north, where a possible N-limitation would restrict any N mineralisation. The treatments, comprising additions of 0, 1, 3 or 6 Mg of granulated wood-ash ha⁻¹, were applied in a randomised block design, replicated three times. Wood-ash from the same batch was used for all treatments at both sites. All factors were measured under laboratory conditions with controlled temperature and moisture levels. The potential CO₂ emissions (kg ha⁻¹ year⁻¹ of CO₂–C) at Torup were significantly higher in the 3 and 6 Mg ha⁻¹ treatments than in the control treatment, and the highest application resulted in an extra loss of 0.5 Mg ha⁻¹ of soil C annually as compared to the control. No such differences were detected at Vindeln. The results suggest that wood-ash application can deplete soil organic C at locations with similar characteristics (N-rich soil, spruce dominated, warm climate) as at Torup in this study.     

Ethnicity, land use and woody vegetation: a case study from south-western Burkina Faso

Woody vegetation in cultivated landscapes in Burkina Faso is influenced by agricultural activities that are in turn influenced by institutional arrangements. Research was undertaken in a village in south-west Burkina Faso to investigate the relationship between species composition, diversity, density, species accumulation and land use category. Additionally the relationship between number of trees, size of farmed land and farmer ethnicity was investigated. Indigenous Tiéfo farmers had on average more than double the number of large (>4 m) trees of Vitellaria paradoxa Gaertn. f., Parkia biglobosa (Jacq.) R. Br. Ex G. Don and Anacardium occidentale L. than farmers belonging to other ethnic groups, but this was partly explained by a larger area being available. Differences between ethnic groups were not significant when expressed per ha. Botanical inventories of fallows more than 4 years old, cultivated parklands and plantations of Mangifera indica L. and A. occidentale showed that tree density and Simpson’s index of diversity for trees were highest in the fallow. Simpson’s index was not significantly different for regeneration, but sample-based species accumulation curves indicated that species accumulation in parklands was faster than in plantations when expressed per individual. The average regeneration density was 12,605, 1,995 and 6,772 seedlings ha^-1 for fallow, parklands and plantations, respectively. This low density for parklands means that species accumulation is slow compared to the other land uses when expressed per unit area. Fallow seems the most efficient way of keeping tree diversity in the agricultural landscape.     

Modeling heliotropic tree growth in hardwood tree species—A case study on Maesopsis eminii

There are many impacts during a tree's life that affect bole development. In Maesopsis eminii, a high-potential timber species in Uganda, studies have shown that the occurrence of strongly bent boles is the overwhelming reason that boles fail quality criteria. This observation is incongruous with the tree architecture model of Roux, which describes M. eminii as a tree with a strong apical dominance, meaning that it has a strong genetically based preference for vertical growth of the terminal sprout relative to side branches. As external causes for bent boles could be excluded, we demonstrate in this study the proof of heliotropic growth, i.e. an active bending towards light, for M. eminii beyond the sapling stage. We develop a model used to describe the effects of competition on bole quality using bole form parameters and basic information about the neighbouring trees, and without having to incorporate crown parameters. By means of calculated bole parameters and a mathematical equation to calculate the intensity and direction of competition, we prove the existence of a heliotropic growth reaction. However, we are not able to predict the intensity of this reaction. Finally, general silvicultural recommendations are discussed for tree species with strong heliotropic growth.     

Corresponding patterns of site quality,decline and tree growth in a sessile oak stand

This study focuses on two rarely studied aspects of oak decline: relations with site characteristics and effects on tree growth. The study was carried out in a 5.5 ha stand in Hungary which is strongly affected by oak decline. The nearly pure sessile oak (Quercus petraea) stand of mostly coppice origin was 90 years old at the beginning of the study. Within-stand site heterogeneity was described by the herbaceous vegetation. Four ecological site types were distinguished by the species composition of herbs, and characterized by the ecological indicator values of the species. Tree growth between 1987 and 1993 was measured, and tree vigour was estimated from visual characteristics five times between 1987 and 1993. Potential volume increment of declining trees was estimated with the growth rates of healthy trees of the same size. Volume increment loss caused by oak decline was also assessed. Significant positive relationships were found between tree vigour and tree size and between tree vigour and tree growth. The growth of seriously declining trees dropped to almost one-half of that of healthy ones. Growth reduction of living trees at the stand level amounted to 5.4%, whereas growth reduction of all trees, including those that died during the observation period, amounted to 19.9% of the potential growth. Tree size and growth were greater on better sites. A strong relationship was also found between tree vigour and site type, but sessile oak was more susceptible to decline at better sites.     

Airborne small-footprint discrete-return LiDAR data in the assessment of boreal mire surface patterns, vegetation, and habitats

Boreal mires encompass high diversity in species and habitats, many of which are endangered. In Finland, extensive use of peatlands has resulted in habitat fragmentation. A need for accurate and cost-efficient vegetation mapping and monitoring of habitat changes exists in mire conservation, restoration and peatland forestry. LiDAR is an emerging and excellent tool for probing the geometry of vegetation and terrain. Modern systems measure the backscattered signal accurately and also provide radiometric information. Experiments were carried out in a complex minerotrophic–ombrotrophic eccentric raised bog in southern Finland (61°47′N, 24.18′E). First, we tested discrete-return LiDAR for the modeling of mire surface patterns and the detection of hummocks and hollows, as well as the effect of mire plants on the Z accuracy of the surface echoes. Secondly, the response of different mire vegetation samples in LiDAR intensity was examined. Thirdly, we tested area-based geometric and radiometric features in supervised classification of mire habitats to discover the meaningful variables. The vertical accuracy of LiDAR in mire surface modeling was high: 0.05–0.10 m. A binary hummock-hollow model that was estimated from a LiDAR-based elevation model matched flawlessly in aerial images and had moderate explanatory power in habitat classification trials. The intensity of LiDAR in open-mire vegetation was mainly influenced by the surface moisture, and separation of vegetation classes spanning from ombrotrophic to mesotrophic vegetation proved to be difficult. Area-based features that characterize the height distribution of LiDAR points in the canopy were the strongest explanatory variables in the classification of 21 diverse mire site types. Actual qualifying differences in the ground flora were unattainable in the LiDAR data, which resulted in inferior accuracy in the characterization of ecohydrological conditions and nutrient level of open mires and sparsely forested wet sites. Mire habitat classification accuracy with LiDAR surpassed earlier results with optical data. The results suggested that LiDAR constitutes an efficient aid for monitoring applications. We propose the co-use of images and LiDAR for enhanced mapping of open mires and tree species. In situ calibration and validation procedures are required until invariant geometric and radiometric features are discovered.     

Effects of the second-generation larch plantations onsoil fertility and tree growth

Larch is one of the most important plantation species in the northeast region of China. After clear cutting of larch plantations it is the urgent problem to besolved that whether the second generation is continuously plant6d, whether the soil fertility is decreasing and the plantstion is how to be managed onthe forestry produCtion. In odder tO realize the secondgenerahon Of larch plantstions and to provide thetheoretical base and the reasonable managementmeasures, we inventoried the groWth o…     

Impact of precommercial thinning on tree growth,lumber recovery and lumber quality in Abies balsamea

Abstract

Precommercial thinning (PCT) is often used to improve stand growth and value. While PCT may accelerate tree growth and reduce mortality, it may also have a negative effect on product quality. This study examined the effect of moderate and heavy thinning on tree growth, lumber recovery and quality in a natural balsam fir [Abies balsamea (L.) Mill.] PCT trial 35 years after thinning. Compared with the control, the heavy thinning increased merchantable tree diameter, stem volume per tree and lumber volume recovery per tree by 41.1%, 100.9% and 92.7%, respectively, reduced the Select Structural grade (the best grade) recovery by 33.7%. Thinning did not affect the no. 2 and better grade yield. There was a 12.2% and 15.0% difference, respectively, in the lumber bending modulus of elasticity (MOE) and modulus of rupture (MOR) between the control and heavy thinning. Moderate thinning had little impact on the visual grade recovery, lumber bending MOE and MOR. Heavy thinning is recommended if the goal is to get sizeable sawlogs in the shortest time, whereas moderate thinning is preferable if the intention is to minimize the negative effects on lumber quality while retaining modest tree growth and lumber recovery. Overall, PCT of very dense young balsam fir stands appears to be an effective and viable silvicultural treatment.     

Relationship between vegetation carbon storage and urbanization: A case study of Xiamen, China

Rapid growth of the Chinese urban population and the expansion of urban areas have led to changes in urban forest structure and composition, and consequently changes in vegetation carbon storage. The purpose of this study is to quantify the effects of urbanization on vegetation carbon storage in Xiamen, a city located in southern China. Data used for this study were collected from 39,723 sample plots managed according to the forest management planning inventory program. Data from these plots were collected in 4 non-consecutive years: 1972, 1988, 1996 and 2006. The study area was divided into three zones, which were defined according to their level of urbanization: the urban core, the suburban zone, and the exurban zone. Total vegetation carbon storage and the vegetation carbon density for each study period were calculated for each zone. Our results show that urban vegetation carbon storage has increased by 865,589.71 t during the period from 1972 to 2006 (34 years) in Xiamen, with a rapid increase between 1972 and 1996, then relatively little change between 1996 and 2006. The increase in vegetation carbon storage is mainly due to the large percentages of the suburban and exurban areas which exist in Xiamen city, and the implementation of reforestation programs in these two zones. The percentage of total regional carbon storage in the city center (urban core), suburbs and exurbs was 5%, 23% and 72%, respectively. This demonstrates that the exurbs store the majority of vegetation carbon, and thus play a critical role in the vegetation carbon storage of the study area. The intensification of urbanization in the future will likely expand the urban core and reduce the area of the suburbs and exurbs, and thus potentially decrease total vegetation carbon storage. This article concludes with a discussion of the implications of these results for vegetation carbon management and urban landscape planning.     

育苗基质对榉树容器苗质量的影响

【目的】为了筛选出适于榉树容器苗生长的最佳基质配比,以提高榉树容器苗的培育质量。【方法】以泥炭土、珍珠岩、蛭石、锯木屑和腐殖土5种材料为原料,按照一定的比例配制成6种基质,以此6种配方基质为供试的育苗基质(其处理编号分别为T1、T2、T3、T4、T5、T6),选择10 cm×5 cm×5 cm的无纺布袋作为育苗容器,进行了榉树容器育苗试验。测定了榉树容器苗的出苗率、形态指标、生物量及生理指标等19个指标,并采用隶属函数法对以不同配方基质培育的容器苗的苗木质量进行了综合评价。【结果】6种基质处理的出苗率从大到小依次为T3>T5>T1>T2>T6>T4,其中T3基质处理的出苗率最高,T4基质处理的出苗率最低,T3基质处理的出苗率是T4基质处理的出苗率的3.47倍;T1基质处理的苗高、地径均极显著高于其他基质处理的,T2基质处理的叶片数显著高于除T1和T5外的其他基质处理的。T2基质处理的侧枝数显著高于其他基质处理的,不同基质处理间容器苗的高径比、侧根数、主根长均无显著差异;T1基质处理的茎干质量、根干质量、苗木干质量及其质量指数均极显著高于其他基质处理的,不同基质处理间容器苗的茎根比无显著差异;T1基质处理的根系活力强度和叶绿素a含量均极显著高于除T2外的其他基质处理的,T2基质处理的叶绿素总量极显著高于除T1外的其他基质处理的,不同基质处理间容器苗的叶绿素b、叶绿素a/b之值均无显著差异,T4基质处理的净光合速率最低,极显著低于其他基质处理的。【结论】采用模糊数学的隶属函数法综合评价得出:以T1基质(其配比为:腐殖土∶泥炭土∶珍珠岩=2∶1∶1)培育的榉树容器苗其质量最好,这种配方基质是榉树容器苗的最佳育苗基质。     

Modifying the microclimate around young oaks through vegetation manipulation: Effects on seedling growth and branching

The objective of this research was to evaluate the influence of vegetation control on the microclimate (light, air temperature, vapor-pressure deficit (VPD)) and on the growth of young planted, sessile oak seedlings. Three types of vegetation control, creating a range of above-ground interaction intensity, were compared. In the open treatment, vegetation was chemically controlled and was maintained at a low height; in the closed treatment, vegetation was manually controlled and a few dominant individuals that overtopped the oak seedlings were cut; and in the sheath treatment, the vegetation in a 0.5-m diameter circle around each seedling was manually cut to a height equal to three quarters of the total seedling height. In all treatments, a strong reduction of incoming radiation was observed, as well as an increase in air temperature and VPD during the day, and a decrease in daily PET, compared to the reference located 4 m above the vegetation. However, the neighboring vegetation did not modify the microclimate around the seedling to a level that could have induced a significant reduction in seedling photosynthesis and, thus, in seedling growth. Seven years after planting, seedlings were shortest in the open treatment and tallest in the closed treatment (334, 372, 378 cm in the open, sheath and closed treatments, respectively). Seedlings in the open treatment allocated proportionally more biomass to diameter increment than to height growth, compared to seedlings in the sheath and closed treatments. The seedlings averaged 1.77, 1.10 and 1.00 forks in the open, sheath and closed treatments, respectively, and the average height of the lowest fork was 171, 206 and 226 cm in the same treatments. The reduction of the number of forks per seedling was not related to a reduction of the appearance of new forks, but rather to a reduction in the persistence of the existing forks. These changes in stem allometry and in fork development seemed to be related to the lateral shade afforded by the vegetation.     

Household tree holdings: A case study in Mutoko communal area, Zimbabwe

Tree holdings at homesteads and in homefields were investigated for two villages in Zimbabwe. Of the households, 90% owned at least one exotic tree. Trees were concentrated at homesteads and conserved indigenous trees tended to be edible fruit trees. Female heads of households (divorcees and widows) had fewer trees than households headed by men. Households with longer period of residence at a site had increased the proportion of indigenous fruit trees compared to non-fruit trees. Wealth status showed no relationship to tree holdings. The considerable tree planting and tree conservation activity around homesteads and in homefields has the effect of replacing non-fruit indigenous trees with exotic and indigenous fruit trees. Agroforestry research, extension and development should focus more on current practices, concentrate more on trees that farmers favour (such as fruit trees) and take into account differences among households. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of diversity of tree species and size on forest basal area growth,recruitment, and mortality

The objective of this study was to determine the relationship, or lack thereof, between growth and diversity of tree species and size in conifer stands of western North America. Growth was measured by net basal area growth and its components: survivor growth, recruitment, and mortality. The analysis used inventory data from permanent plots in the Douglas-fir/western hemlock forest type in Oregon and Washington, and in the mixed-conifer forest type in California. The methods consisted of generalized least square regression with spatial autocorrelation, controlling for the effect of other stand characteristics. Other things being equal, in the two forest types under study there was a strong positive relationship between net basal area growth and tree-species diversity. This effect was associated with higher recruitment in stands of higher tree-species diversity. Neither mortality nor growth of survivors was related to tree-species diversity. The relationship between growth and tree-size diversity was less clear. For Douglas-fir/western hemlock, net basal area growth was negatively correlated with tree-size diversity, essentially because recruitment was lower on plots of high tree-size diversity. For mixed conifers, net basal area growth tended also to be lower in plots of high tree-size diversity, but this was mostly because mortality was higher in plots of higher tree-size diversity.     

源库关系变化对果树产量及果实品质的影响

果树经济产量和果实品质的形成实质上依赖于其源库互作关系,而源库关系的发生受光照、温度等环境因素的影响。因此,了解源库关系变化及环境因子对果树经济价值的影响具有重要意义。但是,目前关于果树源库关系变化及环境因子对果树产量及果实品质的影响问题尚缺乏系统的评述。文中基于源库概念和国内外有关果树源库关系的研究现状,综述了源库关系研究的主要途径、果树源库关系变化与环境因子跟果树产量和果实品质的关系,并对今后的研究方向提出了5条建议。     

造林密度对杨树生长的影响

该文对欧美杨107、雄性毛白杨1319、窄冠白杨3个无性系密度试验林连续6a的定位观测资料进行了分析研究。结果表明:3个无性系6a生时在树高生长、胸径生长、单株材积生长上存在显著差异。密度对3个无性系的胸径生长、单株材积生长影响极为显著。6a生时,单位面积上的林分蓄积量为2m×3m(1667株/hm2)2m×4m(1250株/hm2)4m×6m(417株/hm2)。通过对3个无性系在3个不同密度的生长进程、连年生长量分析,提出了初次间伐的合理年限。     

Effects of afforestation on soil carbon and its fractions: a case study from the Loess Plateau,China

Afforestation has been implemented to reduce soil erosion and improve the environment of the Loess Plateau,China.Although it increased soil organic carbon(SOC),the stability of the increase is unknown.Additionally,the variations of soil inorganic carbon(SIC) following afforestation needs to be reconfirmed.After planting Robinia pseudoacacia,Pinus tabuliformis,and Hippophae rhamnoides on bare land on the Loess Plateau,total soil carbon(TSC) was measured and its two components,SIC and SOC,as well as the light and heavy fractions within SOC under bare lands and woodlands at the soil surface(0–20 cm).The results show that TSC on bare land was 24.5 Mg ha~(-1) and significantly increased to 51.6 Mg ha~(-1) for R.pseudoacacia,47.0 Mg ha~(-1) for P.tabuliformis and 39.9 Mg ha~(-1) for H.rhamnoides.The accumulated total soil carbon under R.pseudoacacia,P.tabuliformis,and H.rhamnoides,the heavy fraction(HFSOC) accounted for 65.2,31.7 and 76.2%,respectively; the light fraction(LF-SOC) accounted for 18.0,52.0 and 4.0%,respectively; SIC occupied 15.6,15.3 and 19.7%,respectively.The accumulation rates of TSC under R.pseudoacacia,P.tabuliformis,and H.rhamnoides reached159.5,112.4 and 102.5 g m~(-2) a~(-1),respectively.The results demonstrate that afforestation on bare land has high potential for soil carbon accumulation on the Loess Plateau.Among the newly sequestrated total soil carbon,the heavy fraction(HF-SOC) with a slow turnover rate accounted for a considerably high percentage,suggesting that significant sequestrated carbon can be stored in soils following afforestation.Furthermore,afforestation induces SIC sequestration.Although its contribution to TSC accumulation was less than SOC,overlooking it may substantially underestimate the capacity of carbon sequestration after afforestation on the Loess Plateau.     

不同施肥处理对3种海岛树种苗木生长及造林效果的影响

为了解不同施肥处理对普陀樟(Cinnamomum japonicum var.Chenii)、全缘冬青(Ilex integra Thunb.)、红楠(Machilus thunbergii Sieb.et Zucc)3种海岛树种苗木生长及造林效果的影响,设置了7个不同的施肥处理,即(1)N(对照),(2)N+P,(3)N+2P、(4)N+K、(5)N+2K、(6)N+1P+1K、(7)N+2P+2K,于2011年5月至2012年1月观测苗高和地径,并测定植物各部分的生物量。结果表明:3种苗木不同施肥处理下,通过测算苗木质量指数QI可知,在N+1K施肥组合下,全缘冬青的苗木质量最好,而红楠在N+2P+2K的施肥组合下苗木质量最高,普陀樟在N+1P+1K的施肥组合下,苗木质量要好于其他处理。     

基质、激素种类和浓度及其交互作用对麻竹扦插生长的影响

为提高麻竹Dendrocalamus latiflorus枝条扦插成活率与生根率,筛选出最佳配方及处理方法,选择1年生麻竹枝条为材料,采用从基质、激素种类及浓度三因素析因设计,研究各因素及其相互作用对麻竹扦插生长的影响,并运用隶属函数法综合评价了育苗效果。结果表明:1)3个主因素中,激素种类对扦插生根影响最大,各指标均达到显著水平;2)泥炭对扦插苗地上的生长指标影响最大,新梢率、新梢数和叶数达显著水平;3)细沙作为基质可以显著提高麻竹枝条扦插生根率,扦插成活率达62.92%;4)两因素交互作用中,激素×浓度的交互作用对扦插生根的影响最大,愈伤率、腐烂率、平均根长、总根数、根系直径等指标均达极显著水平;5)激素种类×激素浓度对扦插地上指标影响最大,叶面积达极显著水平,新梢数达显著水平;6)三因素交互作用中,仅愈伤率和腐烂率达到极显著水平。由此可见,泥炭显著提高扦插生根率,NAA扦插效果最好,激素浓度处于40～80 mg/L时扦插苗各指标最佳;泥炭+ABT+80 mg/L为最佳处理组合。     

Effects of water, nutrients and their interactions on tree growth, and plantation forest management practices in Australasia: A review

The amount and distribution of rainfall throughout the year is used to highlight climatic differences between Australia and New Zealand. Plantation forest growth is strongly influenced by both available moisture and nutrients. Practices such as cultivation and mounding (bedding) are used on wet sites, whereas cultivation, ripping, weed control, mulching andheavier thinning regimes are recommended for dry sites.

Management of nutrients to improve growth includes some of the practices listed above which enhance moisture relationships. Nutrient conservation measures and the selection of planting stock with better root systems to explore the soil are suggested as methods to improve growth, along with the direct application of nutrients in fertiliser, sewage effluents and wastes.

Responses to a questionnaire distributed to the major forestry enterprises in Australia showed that practices with very conspicuous benefits (e.g. weed control) had generally been accepted, but the lead-time for implementation of positive research and development was still excessive. A number of other promising practices (e.g. mycorrhizal inoculation of nurseries) had only received minimal or at best a moderate acceptance by managers.

In reviewing the positive impact of recent past research on management practices, we suggest that more information on the interaction of moisture availability and nutrition along with detailed research on both positive and negative effects of cultivation is required. The potential benefits from the use of wastes and effluents within forests to supply both water and nutrients will ensure the development of this practice. Experiments should be designed to explore the interactions between genetically improved stock, sites and cultural treatments, as well as physiological processes determining growth.     

Forecasting landscape-scale,cumulative effects of forest management on vegetation and wildlife habitat: A case study of issues,limitations, and opportunities

Forest landscape disturbance and succession models have become practical tools for large-scale, long-term analyses of the cumulative effects of forest management on real landscapes. They can provide essential information in a spatial context to address management and policy issues related to forest planning, wildlife habitat quality, timber harvesting, fire effects, and land use change. Widespread application of landscape disturbance and succession models is hampered by the difficulty of mapping the initial landscape layers needed for model implementation and by the complexity of calibrating forest landscape models for new geographic regions. Applications are complicated by issues of scale related to the size of the landscape of interest (bigger is better), the resolution at which the landscape is modeled and analyzed (finer is better), and the cost or complexity of applying a landscape model (cheaper and easier is better). These issues spill over to associated analyses that build on model outputs or become integrated as auxiliary model capabilities. Continued development and application of forest landscape disturbance and simulation models can be facilitated by (1) cooperative efforts to initialize more and larger landscapes for model applications, (2) partnerships of practitioners and scientists to address current management issues, (3) developing permanent mechanisms for user support, (4) adding new capabilities to models, either directly or as compatible auxiliary models, (5) increasing efforts to evaluate model performance and compare multiple models running on the same landscape, and (6) developing methods to choose among complex, multi-resource alternatives with outputs that vary over space and time.