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Range expansions, whether they are biological invasions or climate change-mediated range shifts, may have profound ecological and evolutionary consequences for plant-soil interactions. Range-expanding plants encounter soil biota with which they have a limited coevolutionary history, especially when introduced to a new continent. Past studies have found mixed results on whether plants experience positive or negative soil feedback interactions in their novel range, and these effects often change over time. One important theoretical explanation is that plants locally adapt to the soil pathogens and mutualists in their novel range. We tested this hypothesis in Dittrichia graveolens, an annual plant that is both expanding its European native range, initially coinciding with climate warming, and rapidly invading in California after human introduction. In parallel greenhouse experiments on both continents, we used plant genotypes and soils from five locations at the core and edge of each range to compare plant growth in soil inhabited by D. graveolens and nearby control microsites as a measure of plant-soil feedback. Plant-soil interactions were highly idiosyncratic across each range. On average, plant-soil feedbacks were more positive in the native range than in the exotic range. In line with the strongly heterogeneous pattern of soil responses along our biogeographic gradients, we found no evidence for evolutionary differentiation between plant genotypes from the core to edge of either range. Our results suggest that the evolution of plant-soil interactions during range expansion may be more strongly driven by local evolutionary dynamics varying across the range than by large-scale biogeographic shifts.

The Stress Gradient Hypothesis predicts facilitation will become more important than competition where abiotic stress is high, and the framework successfully predicts positive interactions between species in many systems. Fewer studies have focused on intraspecific facilitation, and to our knowledge none examine intraspecific interactions in Pacific Coast salt marshes of North America. We used two species that tend to occur in large, monospecific patches to test for intraspecific facilitation in a restored California marsh, where tides and evaporation during summer create moisture and salinity gradients across elevation. We tested performance of Frankenia salina or Jaumea carnosa in restoration plots using two treatments: clustered plantings to promote facilitation, and widely spaced plantings to limit interaction between individuals. We characterized the soil water potential gradient and measured plant survival, cover, physiology, and susceptibility to herbivory across elevation and planting treatments. Soil water potential declined sharply with elevation, suggesting plant stress should be higher upslope. However, tissue water potential was unaffected by elevation, and survival was high—suggesting growing conditions remained benign. A seawater addition treatment did not alter the response of plants or plant interactions to the abiotic gradient. At 19 months, intraspecific competition prevailed across the entire elevation gradient for both species, with less transplant cover in clustered plantings. However, clustered Frankenia fared better during a transient period of heavy rabbit herbivory. Aside from this temporary benefit, clustering did not reduce stress and strongly suppressed growth—suggesting that restoration designs for the high marsh should minimize competition.

Dittrichia graveolens (L.) Greuter, or stinkwort, is a weedy annual plant within the family Asteraceae. The species is recognized for the rapid expansion of both its native and introduced ranges: in Europe, it has expanded its native distribution northward from the Mediterranean basin by nearly 7 °C latitude since the mid-20th century, while in California and Australia the plant is an invasive weed of concern. Here, we present the first de novo D. graveolens genome assembly (1N = 9 chromosomes), including complete chloroplast (151,013 bp) and partial mitochondrial genomes (22,084 bp), created using Pacific Biosciences HiFi reads and Dovetail Omni-C data. The final primary assembly is 835 Mbp in length, of which 98.1% are represented by 9 scaffolds ranging from 66 to 119 Mbp. The contig N50 is 74.9 Mbp and the scaffold N50 is 96.9 Mbp, which, together with a 98.8% completeness based on the BUSCO embryophyta10 database containing 1,614 orthologs, underscores the high quality of this assembly. This pseudo-molecule-scale genome assembly is a valuable resource for our fundamental understanding of the genomic consequences of range expansion under global change, as well as comparative genomic studies in the Asteraceae.

Political and economic initiatives intended to increase energy production while reducing carbon emissions are driving demand for solar energy. Consequently, desert regions are now targeted for development of large-scale photovoltaic solar energy facilities. Where vegetation communities are left intact or restored within facilities, ground-mounted infrastructure may have negative impacts on desert-adapted plants because it creates novel rainfall runoff and shade conditions. We used experimental solar arrays in the Mojave Desert to test how these altered conditions affect population dynamics for a closely related pair of native annual plants: rare Eriophyllum mohavense and common E. wallacei. We estimated aboveground demographic rates (seedling emergence, survivorship, and fecundity) over 7 yr and used seed bank survival rates from a concurrent study to build matrix models of population growth in three experimental microhabitats. In drier years, shade tended to reduce survival of the common species, but increase survival of the rare species. In a wet year, runoff from panels tended to increase seed output for both species. Population growth projections from microhabitat-specific matrix models showed stronger effects of microhabitat under wetter conditions, and relatively little effect under dry conditions (lack of rainfall was an overwhelming constraint). Performance patterns across microhabitats in the wettest year differed between rare and common species. Projected growth of E. mohavense was substantially reduced in shade, mediated by negative effects on aboveground demographic rates. Hence, the rare species were more susceptible to negative effects of panel infrastructure in wet years that are critical to seed bank replenishment. Our results suggest that altered shade and water runoff regimes associated with energy infrastructure will have differential effects on demographic transitions across annual species and drive population-level processes that determine local abundance, resilience, and persistence.

Racial and ethnic discrimination persist in science, technology, engineering and mathematics fields, including ecology, evolution and conservation biology (EECB) and related disciplines. Marginalization and oppression as a result of institutional and structural racism continue to create barriers to inclusion for Black people, Indigenous people and people of colour (BIPOC), and remnants of historic racist policies and pseudoscientific theories continue to plague these fields. Many academic EECB departments seek concrete ways to improve the climate and implement anti-racist policies in their teaching, training and research activities. We present a toolkit of evidence-based interventions for academic EECB departments to foster anti-racism in three areas: in the classroom; within research laboratories; and department wide. To spark restorative discussion and action in these areas, we summarize EECB's racist and ethnocentric histories, as well as current systemic problems that marginalize non-white groups. Finally, we present ways that EECB departments can collectively address shortcomings in equity and inclusion by implementing anti-racism, and provide a positive model for other departments and disciplines.

Seed bank survival underpins plant population persistence but studies on seed bank trait-environment interactions are few. Changes in environmental conditions relevant to seed banks occur in desert ecosystems owing to solar energy development. We developed a conceptual model of seed bank survival to complement methodologies using in-situ seed bank packets. Using this framework, we quantified the seed bank survival of two closely related annual desert plant species, one rare (Eriophyllum mohavense) and one common (Eriophyllum wallacei), and the seed bank-environment interactions of these two species in the Mojave Desert within a system that emulates microhabitat variation associated with solar energy development. We tracked 4860 seeds buried across 540 seed packets and found, averaged across both species, that seed bank survival was 21% and 6% for the first and second growing seasons, respectively. After two growing seasons, the rare annual had a significantly greater seed bank survival (10%) than the common annual (2%). Seed bank survival across both species was significantly greater in shade (10%) microhabitats compared to runoff (5%) and control microhabitats (3%). Our study proffers insight into this early life-stage across rare and common congeners and their environmental interactions using a novel conceptual framework for seed bank survival.

The relationship between plant diversity and productivity and the mechanisms underpinning that relationship remain poorly resolved in species-rich forests. We combined extensive field observations and experimental manipulations in a subtropical forest to test how species richness (SR) and phylogenetic diversity (PD) interact with putative root-associated pathogens and how these interactions mediate diversity-productivity relationships. We show that (i) both SR and PD were positively correlated with biomass for both adult trees and seedlings across multiple spatial scales, but productivity was best predicted by PD; (ii) significant positive relationships between PD and productivity were observed in nonsterile soil only; and (iii) root fungal diversity was positively correlated with plant PD and SR, while the relative abundance of putative pathogens was negatively related to plant PD. Our findings highlight the key role of soil pathogenic fungi in tree diversity-productivity relationships and suggest that increasing PD may counteract negative effects of plant-soil feedback.

Non-native tree (NNT) species have been transported worldwide to create or enhance services that are fundamental for human well-being, such as timber provision, erosion control or ornamental value; yet NNTs can also produce undesired effects, such as fire proneness or pollen allergenicity. Despite the variety of effects that NNTs have on multiple ecosystem services, a global quantitative assessment of their costs and benefits is still lacking. Such information is critical for decision-making, management and sustainable exploitation of NNTs. We present here a global assessment of NNT effects on the three main categories of ecosystem services, including regulating (RES), provisioning (PES) and cultural services (CES), and on an ecosystem disservice (EDS), i.e. pollen allergenicity. By searching the scientific literature, country forestry reports, and social media, we compiled a global data set of 1683 case studies from over 125 NNT species, covering 44 countries, all continents but Antarctica, and seven biomes. Using different meta-analysis techniques, we found that, while NNTs increase most RES (e.g. climate regulation, soil erosion control, fertility and formation), they decrease PES (e.g. NNTs contribute less than native trees to global timber provision). Also, they have different effects on CES (e.g. increase aesthetic values but decrease scientific interest), and no effect on the EDS considered. NNT effects on each ecosystem (dis)service showed a strong context dependency, varying across NNT types, biomes and socio-economic conditions. For instance, some RES are increased more by NNTs able to fix atmospheric nitrogen, and when the ecosystem is located in low-latitude biomes; some CES are increased more by NNTs in less-wealthy countries or in countries with higher gross domestic products. The effects of NNTs on several ecosystem (dis)services exhibited some synergies (e.g. among soil fertility, soil formation and climate regulation or between aesthetic values and pollen allergenicity), but also trade-offs (e.g. between fire regulation and soil erosion control). Our analyses provide a quantitative understanding of the complex synergies, trade-offs and context dependencies involved for the effects of NNTs that is essential for attaining a sustained provision of ecosystem services.

Premise of the studySelf incompatibility (SI) in rare plants presents a unique challenge-SI protects plants from inbreeding depression, but requires a sufficient number of mates and xenogamous pollination. Does SI persist in an endangered polyploid? Is pollinator visitation sufficient to ensure reproductive success? Is there evidence of inbreeding/outbreeding depression? We characterized the mating system, primary pollinators, pollen limitation, and inbreeding/outbreeding depression in Erysimum teretifolium to guide conservation efforts.MethodsWe compared seed production following self pollination and within- and between-population crosses. Pollen tubes were visualized after self pollinations and between-population pollinations. Pollen limitation was tested in the field. Pollinator observations were quantified using digital video. Inbreeding/outbreeding depression was assessed in progeny from self and outcross pollinations at early and later developmental stages.Key resultsSelf-pollination reduced seed set by 6.5× and quadrupled reproductive failure compared with outcross pollination. Pollen tubes of some self pollinations were arrested at the stigmatic surface. Seed-set data indicated strong SI, and fruit-set data suggested partial SI. Pollinator diversity and visitation rates were high, and there was no evidence of pollen limitation. Inbreeding depression (δ) was weak for early developmental stages and strong for later developmental stages, with no evidence of outbreeding depression.ConclusionsThe rare hexaploid E. teretifolium is largely self incompatible and suffers from late-acting inbreeding depression. Reproductive success in natural populations was accomplished through high pollinator visitation rates consistent with a lack of pollen limitation. Future reproductive health for this species will require large population sizes with sufficient mates and a robust pollinator community.

Models are simplified representations of more complex systems that help scientists structure the knowledge they acquire. As such, they are ubiquitous and invaluable in scientific research and communication. Because science education strives to make classroom activities more closely reflect science in practice, models have become integral teaching and learning tools woven throughout the Next Generation Science Standards (NGSS). Although model-based learning and curriculum are not novel in educational theory, only recently has modeling taken center stage in K–12 national standards for science, technology, engineering, and mathematics (STEM) classes. We present a variety of examples to outline the importance of various types of models and the practice of modeling in biological research, as well as the emphasis of NGSS on their use in both classroom learning and assessment. We then suggest best practices for creating and modifying models in the context of student-driven inquiry and demonstrate that even subtle incorporation of modeling into existing science curricula can help achieve student learning outcomes, particularly for English-language learners. In closing, we express the value of models and modeling in life beyond the classroom and research laboratory, and highlight the critical importance of “model literacy” for the next generation of scientists, engineers, and problem-solvers.

Species in the early stages of domestication, in which wild and cultivated forms co-occur, provide important opportunities to develop and test hypotheses about the origins of crop species. Chrysophyllum cainito (Sapotaceae), the star apple or caimito, is a semidomesticated tree widely cultivated for its edible fruits; it is known to be native to the neotropics, but its precise geographic origins have not been firmly established. Here, we report results of microsatellite marker analyses supporting the hypothesis that the center of domestication for caimito was the Isthmus of Panama, a region in which few crop species are believed to have originated, despite its importance as a crossroads for the dispersal of domesticated plants between North and South America. Our data suggest that caimito was domesticated in a geographically restricted area while incorporating a diverse gene pool. These results refute the generally accepted Antillean origin of caimito, as well as alternative hypotheses that the species was domesticated independently in the two areas or over a broad geographic range including both. Human-mediated dispersal from Panama to the north and east was accompanied by strong reductions in both genotypic and phenotypic diversity. Within Panama, cultivated and wild trees show little neutral genetic divergence, in contrast to striking phenotypic differentiation in fruit and seed traits. In addition to providing a rare example of data that support the hypothesis of a narrow geographic origin on the Isthmus of Panama for a now widespread cultivated plant species, this study is one of the first investigations of the origins of an edible species of the large pantropical family Sapotaceae

We developed microsatellite primers for the tropical tree Chrysophyllum cainito (Sapotaceae) to determine the native range of the species, investigate the origin of cultivated populations, and examine the partitioning of genetic diversity in wild and cultivated populations. • We developed 10 polymorphic primers from C. cainito genomic DNA libraries enriched for di-, tri-, and tetranucleotide repeat motifs. The loci amplified were polymorphic in samples collected from Jamaica and Panama. The number of alleles per locus ranged from two to 10 and three to 12, while observed heterozygosities ranged from 0.074 to 0.704 and 0.407 to 0.852 in Jamaica and Panama, respectively. • The microsatellite primers will be useful in future population genetic studies as well as those aimed at understanding the geographic origin(s) of wild and cultivated populations.

At Joint Base Lewis-McChord, tree plantations have failed repeatedly in areas that had once supported Douglas fir forest, with Scotch broom invasion replacing forest. Maximizing the effectiveness of Scotch broom control is a top management priority. The studies presented here have two main foci: timing of control relative to the Scotch broom life cycle, and chemical vs. manual control. We also explore the effects of forest edges on Douglas fir seedling survival and mycorrhizal colonization. We set up a large-scale experiment (6.3ha total treatment area) at 5 heavily invaded sites in which all broom was mechanically removed in 2007. Each site contained 4 blocks of 12 treatments. We measured density of newly germinated seedlings using 24m-long, 10cm-wide belt transects, and percent cover of Scotch broom using line-intercept method on 24m transects.Seedling density (representing germination from the seedbank) peaked in year 2 and varied dramatically among sites, with one site showing an averageof nearly 350 seedlings/m2.Scotch broom percent cover in control plots increased most rapidly between years 2 and 3, by the fourth year reaching over 150% cover in one site and around 100% cover in two other sites. In contrast, the slowest growing site had only about 20% cover after four years. Plant size also varied across sites. By the fourth year, average plant height was around 2.5m in two of the sites, but only around 1m in the slowest growing site. Chemical vs. mechanical control of seedlings.We compared different approaches to removing broom seedlings at a large scale. Mechanical control comprised “scarifying” the soil to scrape off all seedlings with a mulcher, while chemical control was a broadcast spray of triclopyr herbicide.  We also compared a single scarify treatment to multiple years of treatment (to stimulate and then exhaust the seedbank). With percent cover three years later as the response variable, we found few generalizable differences among treatments. In two sites, herbicide strongly reduced (by over 75%) Scotch broom cover. In one site, multiple years of scarification reduced (by about 50%) cover. Chemical control across seasons.We incorporated the question of seasonality into the herbicide component of our experiment because of a lack of consensus among practitioners about the best time of year to spray Scotch broom. We sprayed whole plots (56’ x 56’) with Garlon 4 Ultra (triclopyr) in March, May, or September of 2009, and quantified percent cover of Scotch broom in 2012. All the spray treatments had strongly reduced broom cover relative to controls, with the exception of one site that had very low cover altogether. The effect of the treatment did not vary with season in four of the five sites. In the fifth site, March spray was less effective. Chemical vs. mechanical control of older plants.We compared brushcutting to triclopyr spray on 2.5-year old plants in September 2010,.  Herbicide led to a significantly higher kill rate per plant, consistently 80-95% across all sites, compared to variable rates (25-95%) for brush cutting. However, two years later percent cover of Scotch broom was showing only a non-significant trend toward better results with herbicide. Both brushcutting and triclopyr spray strongly reduced percent cover of Scotch broom compared to the untreated control in all but one site. Edge effects, soil inoculum, and mycorrhizae.Our early studies suggested that Douglas-fir seedlings planted near adult trees or forest edges established with much higher success than more isolated seedlings. We did a large-scale, well-replicated experiment to test whether tree establishment was consistently higher near forest edges, and also whether mycorrhizal fungi play a role in this edge effect. At the same five sites, we established transects along forest edges and paired transects 15-25m out into the clearcut. We planted 958 Douglas fir seedlings, and we transplanted soil with each seedling: half received forest soil and the other half received soil from the invaded clearcut. Survival was much higher on the forest edge, and mycorrhizal colonization was also higher on the edge.  However, the effect of transplanting soil inoculum was not significant, and even the non-significant trend disappeared completely by the second year. Our results suggest that sites that are otherwise inhospitable for young trees and in which plantations have failed may still show potential to regenerate slowly, starting at the edges. These results also have implications for how the geometry of forest harvest methods influences reforestation success.

Sustainable forestry has been practiced for over a hundred years on the 16,000 ha of commercial forest lands on Joint Base Lewis-McChord. In the latter half of the 20thcentury, the invasive shrub Scotch broom spread across the base, creating new challenges for reforestation efforts. Large areas of forest were essentially taken over by Scotch broom after trees were harvested.  Plantations have shown repeated failures, resulting in serious financial losses as well as a negative effect on military training. The primary objective of our project was to examine the impact of Scotch broom on establishment and growth of Douglas fir seedlings, and the effectiveness of different approaches to Scotch broom control in the forestry context. Here we report results from a number of related studies on [1] Douglas fir survival in previously invaded clearcuts, [2] Edge effects on Douglas fir survival, [3] Stimulating germination with disturbance, [4] Increase in Scotch broom cover after initial removal, [5]Variation across seasons in the effectiveness of Garlon 4 (triclopyr) herbicide, and [6]Legacy effects: Scotch broom effects on soil. 1. Douglas fir survival in previously invaded clearcuts. We set up a large-scale experiment (6.3ha total treatment area) with 12 treatments at 5 sites. We planted 7,448 two-year-old Douglas fir seedlings in March 2008 and censused 3,800 focal trees. In response to very high mortality, we replanted all focal trees in November 2008 or in March 2009. By September 2009, over 90% of these tree seedlings had died. This was the first documented evidence that direct competition from Scotch broom was not involved in Douglas fir plantation failure. Rather, soil or other abiotic conditions in the invaded clearcuts made these sites inhospitable to Douglas fir regeneration. We found no significant difference in survival between trees planted in November and trees planted in March.2. Edge effects on Douglas fir survival. In a smaller study of 424 tree seedlings planted at different distances from two forest edges, we found a significant effect of distance from the nearest adult tree, and no difference between a north-facing and a south-facing edge, on survival through the first year. In another related study in March 2009, we planted Douglas fir seedlings along the edges of the same clearcuts described above, and we found higher survival along those edges than in the center of the clearcuts.3. Stimulating germination with disturbance. Soil scarification is thought to stimulate germination of Scotch broom seeds out of the seedbank, relative to germination from seeds below established vegetation.We tested whether this effect of scarification is due to the physical disturbance of the soil or simply due to the removal of shade and competing vegetation. We compared Scotch broom germination from (1) control plots that had two-year-old undisturbed vegetation including Scotch broom, (2) plots scarified the previous year, and (3) plots treated with triclopyr the previous year. We found that both treatments had significantly more germination relative to the control, showing that part of the response to scarification is simply the removal of competition from established vegetation. In addition, scarified plots had significantly higher germination than herbicide plots, confirming that soil disruption had an additional stimulating effect on Scotch broom germination.4. Increase in Scotch broom cover after initial removal.We tracked the rate of increase in percent cover of the invader Scotch broom over time in five sites. Patterns of Scotch broom cover after two years closely tracked patterns of seedling density in the first year rather than patterns of stump resprouting. However, after three years, the rank order of Scotch broom cover began to diverge from the initial germination data.5. Variation across seasons in the effectiveness of Garlon 4 (triclopyr) herbicide. Restoration experts differ in their opinions about when is the best time to treat Scotch broom, often advocating for the importance of targeting the peak flowering season, or the dry season when the plant is most stressed. We quantified the effectiveness of chemical control in different seasons, spraying whole plots (56’ x 56’) with Garlon 4 Ultra (triclopyr) in March, May, or September of 2009, and measuring percent cover of Scotch broom in 2010. For this short-term response, all the spray treatments had strong effects relative to controls, and the effect of treatment seasonality was very small by comparison.6. Legacy effects: Scotch broom effects on soil. Scotch broom is a nitrogen-fixing plant and therefore may ‘fertilize’ soils with increased N. At the same time, however, the plant produces N-rich defense compounds (alkaloids) that have been shown elsewhere to inhibit the growth and activity of some plants and microbes. Both of these effects may affect Douglas fir growth not only directly, but also indirectly via mycorrhizal associations, which may themselves be altered by changes in soil chemistry. We did a 19-month greenhouse experiment comparing invaded and uninvaded soils, with amendments of Scotch broom “mulch” (plant material added) and activated carbon (to bind allelochemicals). Both Douglas fir growth and mycorrhizal colonization were suppressed in invaded soils. Adding Scotch broom mulch to uninvaded soils increased Douglas fir growth, suggesting a nitrogen fertilization effect, but only in the presence of activated carbon.

Domestication Syndrome in Caimito ( Chrysophyllum cainito L.): Fruit and Seed Characteristics: The process of domestication is understudied and poorly known for many tropical fruit tree crops. The star apple or caimito tree (Chrysophyllum cainito L., Sapotaceae) is cultivated throughout the New World tropics for its edible fruits. We studied this species in central Panama, where it grows wild in tropical moist forests and is also commonly cultivated in backyard gardens. Using fruits collected over two harvest seasons, we tested the hypothesis that cultivated individuals of C. cainito show distinctive fruit and seed characteristics associated with domestication relative to wild types. We found that cultivated fruits were significantly and substantially larger and allocated more to pulp and less to exocarp than wild fruits. The pulp of cultivated fruits was less acidic; also, the pulp had lower concentrations of phenolics and higher concentrations of sugar. The seeds were larger and more numerous and were less defended with phenolics in cultivated than in wild fruits. Discriminant Analysis showed that, among the many significant differences, fruit size and sugar concentration drove the great majority of the variance distinguishing wild from cultivated classes. Variance of pulp phenolics among individuals was significantly higher among wild trees than among cultivated trees, while variance of fruit mass and seed number was significantly higher among cultivated trees. Most traits showed strong correlations between years. Overall, we found a clear signature of a domestication syndrome in the fruits of cultivated caimito in Panama.

The pest plant Scotch broom (Cytisus scoparius) is hindering effective reforestation at Fort Lewis, resulting in both a loss of land available for military training as well as a loss of native forest habitat for native plants and animals. Our primary objective was to examine the relative effectiveness of different broom control strategies that are appropriate for the forestry context, where the use of fire is not permitted. This document reports on the first year’s activities of a large research collaboration between personnel at the University of California Santa Cruz and at Fort Lewis. Key research questions include: What are the costs and benefits of an extended preliminary treatment phase, including two or even three years of soil scarification and control of small broom plants before planting? What is the relative effectiveness of chemical and mechanical treatment?We set up a large-scale experiment (6.3ha total treatment area) at 5 sites, with a blocked design of 4 blocks per site with 6 plots per block. The plots were 56’x56’, designed to accommodate 49 tree seedlings (7x7) at 8’ spacing.  Scotch broom plants were removed from the entire site in fall of 2007 before the start of the experiment. We quantified Scotch broom stump density, mean diameter and height in each plot, as well as stump resprout rate and number of seedlings in spring of 2008. Initial stump density and size varied across sites. The resprout rate was low in four of the five sites, averaging 4 - 13% of stumps, but one site showed a very high resprout rate of 36%. Average seedling density, representing germination from the seedbank, varied across sites from 100 seedlings/m2. Most of the variation in seedling number was among sites (56%), followed by small-scale variation from quadrat to quadrat (30%), and plot to plot (12%). Almost no variation was seen across blocks within sites. We planted 7,448 two-year-old Douglas fir seedlings in March 2008. Over half of all Douglas fir seedlings died between March and September in almost all blocks, with close to 100% of the trees dying in one site, and over 80% of trees dying in some of the blocks of all sites. This was an unexpectedly high mortality rate, substantially higher mortality in these invaded clearcuts than mortality seen in other reforestation projects in smaller forest clearings on Fort Lewis.