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Response to Hurricanes of Pinus caribaea var hondurensis Plantations in Puerto Rico
Ariel E. Lugo, Carlos D. Rodríguez Pedraza, Ian Fremont, and Iván Vicens

Caribbean Naturalist, No. 43

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Caribbean Naturalist 1 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 22001177 CARIBBEAN NATURALIST No. 43N:1o–. 1463 Response to Hurricanes of Pinus caribaea var hondurensis Plantations in Puerto Rico Ariel E. Lugo1,*, Carlos D. Rodríguez Pedraza1, Ian Fremont2, and Iván Vicens1 Abstract - We studied the response to hurricanes of 2 Pinus caribaea Morelet var. hondurensis Barr. & Golf. (Honduran Pine) plantations and paired secondary forests over a period of 32 years (1982 to 2014). Plantations differed in age (38 and 53.5 years old), as did the paired secondary forests. The study included the passage of 2 hurricanes (1989 and 1998). The hurricanes altered forest structure by lowering the basal area and tree density, accelerated tree mortality to over 5% per year and ingrowth rate to over 200 stems/ha at the Cubuy plantation, caused variability and reduction in individual tree growth rates, and dramatically changed species composition and dominance of stands. Honduran Pines were heavily affected by the hurricanes, losing dominance, and almost disappearing from the Cubuy site, in effect converting that pine plantation into a secondary forest with few pines. The susceptibility of Honduran Pine to strong winds raises concern about its suitability for plantation forestry in the hurricane belt of the Caribbean. Their use for commercial timber production would have to consider the recurrence of hurricanes in the region. Introduction The suitability of introduced species for plantation forestry is usually assessed through planting trials that might or might not last through the expected rotation times for the species under consideration. In regions such as the Caribbean with large and infrequent disturbances (LID), it may be possible to test species suitability during disturbance-free periods and thus miss their response to LID events that can transform stands and uncover a vulnerability to those LID events. This may be the case for Pinus caribaea Morelet var. hondurensis Barr. & Golf. (Honduran Pine), a lowland tropical pine species variety from Central America that was widely tested and found suitable for plantation forestry in Puerto Rico after several decades of research between the 1960s and 1980s (e.g., Briscoe 1959, 1962; Liegel 1984a; Whitmore and Liegel 1980). That period of time was almost hurricane-free in the island, allowing experimental plantations to accumulate large wood volumes and exhibit high timber yields (Francis 1995, 2000; Liegel 1984a; Lugo 1992). The passage of 2 hurricanes, in 1989 and 1998, over our study sites gave us the opportunity to examine both the immediate and long-term effects of LID events on the suitability of Honduras Pine to the Caribbean island region. 1USDA Forest Service International Institute of Tropical Forestry, 1201 Ceiba Street, Jardín Botánico sur, Río Piedras, PR 00926-1115. 2State University of New York College of Environmental Science and Forestry, 1 Forestry Dr, Syracuse, NY 13210. *Corresponding author - alugo@fs.fed.us. Manuscript Editor: Shauna Lee-Chai Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 2 Field Site Description The field sites and methods used in this research follow those described by Lugo (1992) for a comparative study of Honduran Pine and Swietenia macrophylla King (Big-leaf Mahogany) tree plantations with paired secondary forests. Plantations and paired secondary forests were located next to each other, and had the same aspect and land-use history (Lugo 1992). The study was conducted in the lower elevations of the Luquillo Experimental Forest/El Yunque National Forest, PR, USA (Fig. 1). All sites are in the subtropical wet forest life zone sensu Holdridge (1967). Methods We studied the 2 pine plantations and their paired secondary forest stands dominated by native tree species. Plantations were established in 1976 (Guzmán) and 1961 (Cubuy) with tree spacing of 3 m by 3 m (Lugo 1992). Secondary forests were of similar age and grew under similar conditions as their paired tree plantations. We re-measured all study-site trees in 2007 and 2014 and tagged and identified to species untagged trees in a 40 m by 50 m plot in each plantation and paired secondary Figure 1. Location of study sites in the Luquillo Experimental Forest/El Yunque National Forest. The plantation and paired secondary forest were adjacent to each other at each site. Topographic elevations and the trajectory of hurricanes Hugo and Georges are shown. The locations correspond to latitude 18°N and longitude 65°W. The plot locations in minutes and seconds of latitude and longitude (respectively) are as follows: Cubuy pine plantation: 16'32.13" and 52'10.03"; Cubuy secondary: 16'36.01" and 52'08.29"; Guzmán pine plantation: 19'49.66" and 49'59.41"; and Guzmán secondary: 19'43.38" and 50'03.34". Caribbean Naturalist 3 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 forest. All trees with a diameter at breast height (dbh; 1.37 m off the ground) of >4.0 cm were measured and identified to species. Before our 2007 and 2014 measurements, trees had been tagged, identified to species, and measured in 1982, 1984, 1989, and 1990. The Cubuy plantation was also re-measured in 1996. In 2014, the plantations were 38 (Guzmán) and 53.5 (Cubuy) years old. Hurricanes Hugo (in 1989) and Georges (in 1998) affected the stands after they were first measured in 1982 to 1984 by Lugo (1992). Rodríguez Pedraza (1993) reported the immediate effects of Hurricane Hugo on all plantations and paired secondary forest sites and reported the changes in basal area and tree density between 1982 and 1990 used here. We added 2007 and 2014 estimates of basal area, tree density, species density and importance value (IV), tree ingrowth rates, tree mortality rates, and tree basal-area growth rates to available data from previous measurements in both pine plantations and paired secondary forest stands. Stand basal area was the sum of individual tree basal area divided by plot area. Individual tree basal area was derived from dbh measurements. Tree density was the number of trees divided by plot area. Species density was the number of tree species per area sampled (0.2 ha). A species IV is its relative density plus its relative basal area expressed in percent. Species relative tree density and relative basal area are expressed in percent of the stand’s total tree density and basal area, respectively. We ranked species by their IV and constructed IV curves sensu Whittaker (1970). We also calculated the Sørensen similarity index (Sørensen 1948) for plantation and secondary forest species assemblages at different times throughout the study. Tree ingrowth rates were the number of trees entering the 4-cm dbh class since the previous re-measurement divided by the elapsed time in years. Similarly, tree mortality was the number of trees that died between measurement intervals divided by the elapsed time between measurements. Mortality rates were also expressed as the percent of trees dying relative to the number of live trees at the beginning of the interval, divided by the time elapsed. We estimated individual tree growth by species at the Cubuy site for 6 time intervals: 1982–1990, 1982–1996, 1990–1996, 1990–2007, 1996–2007, and 2007–2014. Estimates were based on the change in basal area of tagged trees during the interval divided by the elapsed time in years. Results Forest structure Tree density declined before the 1989 hurricane in all stands (Fig. 2). Tree density also declined in all stands after the 1989 hurricane and reached a low value in the 1996 measurement of the Cubuy plantation. By 2007, all stands had higher tree densities than when initially measured in 1982, with the exception of the Cubuy secondary forest. Between 2007 and 2014, all stands exhibited a reduction in tree density (Fig. 2). Between 1982 and 1990, tree density in the Cubuy secondary forest was higher than in the paired pine plantation, and the pattern reversed between 2007 and 2014, with the pine plantation exhibiting a higher tree density than the paired secondary forest. The opposite pattern was observed in the Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 4 paired Guzmán plantation and secondary forest, with higher initial tree density in the Guzmán plantation and higher tree density in the paired secondary forest than in the Guzmán plantation between 2007 and 2014 (Fig. 2). Basal area in the Cubuy plantation declined after the 1989 hurricane, reaching a low value just before the 1998 hurricane (Fig. 3). The post-hurricane increase in basal area after 1996 was relatively slow at the Cubuy plantation, and values Figure 2. Tree density in Pinus caribaea var. hondurensis (Honduran Pine) plantations and paired secondary forests at 2 sites in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998 (black arrows). Data are for all trees with dbh > 4 cm. The lines connecting data points are for illustrative purposes only. Figure 3. Tree basal area in Pinus caribaea var. hondurensis (Honduran Pine) plantations and paired secondary forests at 2 sites in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998 (black arrows). Data are for all trees with dbh > 4 cm. The lines connecting data points are for illustrative purposes only. Caribbean Naturalist 5 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 remained below those at the beginning of the study in 1982. However, the basal area of the Guzmán plantation was increasing before the 1989 hurricane, decreased as a result of the hurricane, and reached its highest values between 2007 and 2014. The two pine plantation stands always had higher basal area than the corresponding paired secondary forest. After the passage of the 1998 hurricane, the Guzmán plantation had a higher basal area than the Cubuy plantation. The Cubuy secondary forest lost some basal area after the 1989 hurricane but in general retained a similar level of its pre-hurricane basal area. The Guzmán secondary forest also lost some basal area after the 1989 hurricane but by 2014 had a higher basal area than the Cubuy secondary forest (Fig. 3). Both secondary forests had a lower basal area than their paired plantations. Forest processes Annual tree mortality exceeded 5% in all stands immediately after hurricane Hugo in 1989 and was 6.8% in 2007 at the Cubuy plantation 9 years after the passage of hurricane Georges in 1998 (Fig. 4). Before 1989 and by 2014, annual tree mortality rates were well below 5% in all stands. The Guzmán plantation experienced almost 3 times the tree mortality rate observed in the Cubuy plantation after the 1989 hurricane. After the 1989 hurricane, the Cubuy plantation experienced less tree mortality than both of the secondary forests, but the Cubuy secondary forest Figure 4. Tree mortality rates in Pinus caribaea var. hondurensis (Honduran Pine) plantations and paired secondary forests at 2 sites in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998. The 1990 data represents the instantaneous hurricaneinduced tree mortality. Data are for all trees with dbh > 4 cm. Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 6 experienced higher tree mortality than the Guzmán secondary forest or the Cubuy plantation. All forest stands had similar low levels of tree mortality in 2014. By 2007, the Cubuy plantation had a high rate of tree ingrowth and so did the other three stands but at much lower levels (Fig. 5). In 2014, ingrowth levels in all stands were lower than before the 1989 hurricane. The basal area growth rate of trees in the Cubuy plantation exhibited a shift in the frequency of observed growth rates from prior to the hurricanes during 1982– 1990 to after the hurricanes during 2007–2014 (Fig. 6). Before the hurricanes, Figure 5. Tree ingrowth to the 4-cm diameter class or higher in Pinus caribaea var. hondurensis (Honduran Pine) plantations and paired secondary forests at 2 sites in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998 (black arrows). Data are for all trees regardless of species. The lines connecting data points are for illustrative purposes only. Figure 6. Histogram of basal area tree growth in Pinus caribaea var. hondurensis (Honduran Pine) plantations and paired secondary forests in Cubuy, Luquillo Experimental Forest. Hurricanes affected the site in 1989 and 1998. Data are for all trees with dbh > 4 cm. Caribbean Naturalist 7 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 Figure 7. Basal area growth of selected tree species in a Pinus caribaea var. hondurensis (Honduran Pine) plantation in Cubuy, Luquillo Experimental Forest. Hurricanes affected the site in 1989 and 1998. The species codes and number of trees (for 1982–1990, 1982–1996, 1990–1996, 1990–2007, 1996–2007, and 2007–2014 intervals) respectively, are: Alchornea latifolia (ALLA: 3, 2, 3, 1, 0, 28), Casearia arborea (CAAR: 17, 5, 8, 7, 4, 190), Cecropia schreberiana (CESC: 10, 4, 5, 0, 1, 30), Pinus caribaea var hondurensis (PICA: 79, 15, 10, 4, 1, 3). Didymopanax morototoni (synonymous with Schefflera morototoni; SCMO: 40, 18, 21, 13, 6, 41), other 10 species: 5, 3, 5, 1, 1, and 65. Error bars correspond to the standard error of the mean. Data are for trees with dbh > 4 cm. ~30% of the trees in the plantation grew at rates that exceeded 11 cm2/yr and the slower growing trees (0 to 4 cm2/yr) comprised ~28% of plantation trees. In the 2007–2014 interval, fast growing trees represented ~10% of the trees while ~60% of the trees were growing at rates below 4 cm2/yr. Basal area growth in the Cubuy secondary forest did not change over the same time interval, as slower growing trees were always prevalent at this site (Fig. 6). The average growth rate of pines was always faster and more variable than tree growth of non-plantation species at Cubuy, except after the 1998 hurricane when surviving trees grew at very low rates, resuming faster growth rates between 2007 and 2014 (Fig. 7). During the 2007–2014 interval, 2 common secondary forest species growing in the pine plantation exhibited contrasting growth rates, with the native Tabebuia heterophylla (DC.) Britton (White Cedar) sustaining a faster growth rate than the non-native Syzygium jambos (L.) Alston (Rose Apple) (Fig. 8). Forest species composition and dominance The species density of the surveyed stands changed throughout this study, with a convergence by 2014 among stands in the number of species (Fig. 9). In general, the plantations gained species while the secondary forests lost species. The species IV curves (Fig. 10) show that dominance (the IV for the species ranked 1) was higher in the plantations than in the paired secondary forest and tended to decline over time. Also, as the dominance decreased, the IV curve had more species and the initial steepness of the curve for the top ranked species declined. As plantations Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 8 aged, they lost dominance and gained species. The dominance of secondary forests remained more similar within stands as they aged. The identity and IV of the top 2 ranked species changed throughout the study in all stands (Table 1). There was no change in the top-ranked species at the Guzmán site, but the second-ranked species changed in both the plantation and paired secondary forest. The second-ranked species gained IV over time. At the Cubuy plantation, the top-ranked, but not the second-ranked, species changed. At the Cubuy secondary Figure 8. Basal area tree growth of 2 species inside a Pinus caribaea var. hondurensis (Honduran Pine) plantation in Cubuy, Luquillo Experimental Forest. Hurricanes affected the site in 1989 and 1998. The species codes and number of trees for the 1982–1990, 1990–2007, and 2007–2014 intervals, respectively, are: Tabebuia heterophylla (TAHE, 35, 23, 28) and Syzygium jambos (45, 21, 65). Error bars correspond to the standard error of the mean. Data are for trees with dbh > 4 cm. Figure 9. Species density in Pinus caribaea var. hondurensis (Honduran Pine) plantations and paired secondary forests at 2 sites in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998 (black arrows). The line connecting data points is for illustrative purposes only. Data are for trees with dbh > 4 cm in 0.2-ha plots. Caribbean Naturalist 9 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 forest, the top-ranked species changed in 2007 but regained top ranking in 2014, after alternating with the second-ranked species. The IV of pines declined in both plantations throughout the study (Fig. 11). In Cubuy, pines almost disappeared, while at Guzmán they lost almost half of their original IV. The distribution of trees by diameter class at the Cubuy plantation in 2014 showed the dominance of the 5–10-cm dbh class and the loss of the large pines measured in 1982 (Fig. 12). Discussion The results of this study are influenced by stand age, temporal succession, hurricane effects, and by the characteristics of the species involved. When these stands were first surveyed in 1982, the plantations were 4 years and 18.5 years old. While the study stands maintained their age differential at the time of this later study, they were 32 years older and thus temporal successional effects had come into play as well as the age of the forest. Temporal succession affects the pattern of change in parameters, whereas age effects influence the level that parameters reach at a given momen t. Therefore, the differences in tree density (Fig. 2), basal area (Fig. 3), and species density (Fig. 9) Figure 10. Importance value curves for different years for Pinus caribaea var. hondurensis (Honduran Pine) plantations (left column) and paired secondary forests (right column) at 2 sites (Guzmán [top panels]; and Cubuy [bottom panels]) in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998. Data are for trees with dbh > 4 cm. Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 10 before 1989 reflect age differences between stands, while the direction of change in these parameters reflect temporal successional phenomena such as stand thinning and growth reflected in basal area increases. Succession processes also explain stand changes between 2007 and 2014 (Figs. 2, 3, 4, 5), which reflect stand thinning, growth of trees, and low tree mortality and ingrowth a decade or more after the passage of the 2 hurricanes. Tree mortality (Fig. 4) and ingrowth (Fig. 5) rates were low during the early and end periods of the study relative to elevated rates in the years more immediately following the hurricanes. Lugo and Scatena (1996) suggested that tropical forests typically had background rates of tree mortality lower than 5% per year. The passage of hurricane Hugo changed stand structural and functional parameters as well as the immediate direction of successional processes. Table 1. The first and second ranked species in Honduran Pine plantations and paired secondary forests at 2 sites in the Luquillo Experimental Forest, PR, over time. Importance value (IV) for each is given below the species name. The years correspond to the inventory of vegetation. Hurricanes Hugo and Georges affected the sites in 1989 and 1998, respectively. Schefflera morototoni (Aubl.) Maguire, Steyerm., & Frodin (Matchwood) is synonymous with Didymopanax morototoni (Aubl.) Decne. & Planch. Site/ Pine plantation Secondary forest year First rank Second rank First rank Second rank Guzmán 1982 Pinus caribaea* Myrcia splendens Tabebuia heterophylla Miconia prasina 97.7 0.6 63.8 3.1 1990 Pinus caribaea* Miconia prasina Tabebuia heterophylla Psidium guajava* 81.8 6.8 61 6.5 1996 2007 Pinus caribaea* Miconia tetranda Tabebuia heterophylla Calophylum calaba 52.8 23.7 49.46 15 2014 Pinus caribaea* Miconia tetranda Tabebuia heterophylla Calophylum calaba 58.6 15.8 44.1 18.6 Cubuy 1982 Pinus caribaea* Schefflera morototoni Tabebuia heterophylla Syzygium jambos* 72 10.2 33.4 15.5 1990 Pinus caribaea* Schefflera morototoni Tabebuia heterophylla Syzygium jambos* 71.5 10.4 30.4 19.5 1996 Pinus caribaea* Schefflera morototoni 46.1 18.8 2007 Cyathea arborea Schefflera morototoni Syzygium jambos* Tabebuia heterophylla 37 19.8 23.9 21.9 2014 Cyathea arborea Schefflera morototoni Tabebuia heterophylla Syzygium jambos* 38.8 15.4 24.1 22.2 * Naturalized species. Caribbean Naturalist 11 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 Hurricane effects The immediate (less than a decade) effects of hurricanes on the structure of tropical forests have been well documented and understood, and our results are consistent with published literature (Lugo 2008). Hurricane winds open forest canopies; cause greater effects on large trees relative to small ones (Fig. 12), cause elevated tree mortality rates above 5% per year (Fig. 4), reduce tree growth rates (Fig. 6), increase the variability of individual tree growth rate (Fig. 7), accelerate tree ingrowth rates (Fig. 5), cause lag effects on post-hurricane mortality (e.g., the 6.8% per year 9 years Figure 11. Importance value of Pinus caribaea var. hondurensis (Honduran Pine) over time at 2 sites in the Luquillo Experimental Forest. Hurricanes affected the sites in 1989 and 1998 (black arrows). Data are for trees with dbh > 4 cm. Figure 12. Histogram of tree diameter classes at a Pinus caribaea var. hondurensis (Honduran Pine) plantation in Cubuy, Luquillo Experimental Forest in 1982 and 2014. Hurricanes affected the site in 1989 and 1998. Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 12 after Hurricane Georges in Fig. 4), and cause dramatic changes in tree density and basal area (Figs. 2, 3). The maximum basal area measured in the Guzmán plantation was half the basal area observed in the Cubuy plantation at similar ages (Fig. 3). We attribute this lower value to the cumulative effects of the 2 hurricanes, which greatly affected and killed the fast-growing pines. A surprising finding was the disproportional effect of hurricane winds on Honduran Pine growth (Fig. 6) and IV (Fig. 11). Surviving pines experienced a reduction in growth, and an increased variability in growth rates after the hurricanes as a result of canopy and branch loss (Rodríguez Pedraza 1993). Pines also lost dominance in the plantations and almost disappeared in the Cubuy plantation, resulting in the transformation of the plantation into a secondary forest dominated by non-plantation tree species (Fig. 9, Table 1). As the pines lost dominance, the difference in IV between the top- and second-ranked species diminished, reflecting the increasing number of species in the stands as a result of increasing ingrowth rates in the developing secondary forests (Fig. 5). The hurricanes had a greater effect on pine trees that had reached large diameter classes (Fig. 12). With the fall of these large trees, the canopy opened to a greater extent than it would have opened by slower tree mortality due to age. A succession of non-plantation tree species was initiated as a result of the loss of canopy due to the hurricanes. The plantations became enriched with other tree species at the expense of the declining pines (Fig. 9). The growth of non-plantation tree species in plantations varied by species (Fig. 8), thus affecting which species would prevail over the long-term. In Cubuy, the dominant species was Cyathea arborea (L.) J.E. Smith (West Indian Treefern), a species that requires high levels of light and whose presence reflected the large canopy openings as a result of the fall of large pine trees. Nearby Prestoea montana (Graham) G. Nicholson (Sierran Palm) brakes had similar changes in their top dominant species when the same hurricanes affected them (Lugo and Frangi 2016). While C. arborea increased in IV in the palm brakes after the hurricanes, the species that dominated in those forests was Cecropia schreberiana Miq. (Yagrumo Hembra), another indicator species for large canopy openings. Change in species dominance of stands is a function of the strength of hurricane effects, which in turn is influenced by the aspect of forests (Boose et al. 1994). Our results are consistent with those of Lugo and Frangi (2016) for palm brakes and Dacryodes excelsa Vahl (Tabonuco) forests nearby. They suggest that the Guzmán plantation was located windward to the 1989 hurricane Hugo’s winds and leeward to those of 1998 hurricane Georges. The Cubuy plantation had the opposite aspect effect, i.e., it was windward to hurricane Georges and leeward to hurricane Hugo winds. Figure 1 illustrates the positioning of the plots relative to the trajectory of the hurricanes. Thus, the Guzmán plantation was more affected by hurricane Hugo, and the Cubuy plantation was most affected by hurricane Georges. By 2014, forest processes had returned to pre-hurricane rates while stand structure and species composition had not because stand age and temporal successional effects precluded a return to 1982 values. Caribbean Naturalist 13 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 Comparison of plantations with secondary forests Before the 1989 hurricane, the plantations had lower tree density, higher basal areas, lower species densities, and higher dominance than the paired secondary forests (Figs. 2, 3, 9, 10). Tree growth rates (Fig. 6) were faster in the plantation (because of the pines; Fig. 7) than in paired secondary forests, but rates of tree mortality and ingrowth were similar (Figs. 4, 5). Plantations experienced a greater loss of basal area and biomass after hurricane Hugo than did the secondary forests (Rodríguez Pedraza 1993), but the hurricane-induced rates of tree mortality were different (Fig. 4). The differences in biomass and basal area reduction probably reflect the greater structural development of the plantations relative to the secondary forests. Also, plantation trees allocate less biomass to roots than secondary forests (Lugo 1992). The observed differences in tree mortality rates were probably due to aspect in relation to wind direction (discussed above). Convergence in tree density, basal area, and species density occurred among paired stands as species composition changed in the plantations with the loss of pine dominance and ingrowth of non-plantation tree species, i.e., the plantations became secondary forests and in so doing, gained species, had smaller and younger trees, and had more of them. Over the course of the study, the species assemblages of plantations and secondary forests changed in composition resulting in dramatic differences in their similarity (Table 2). The Cubuy plantation species assemblage of 1982 was 60% similar to its 1996 species assemblage and 67% similar to its 2007 species assemblage. By 2014, the Cubuy plantation species assemblage was 90% similar to its 2007 species assemblage but only 36% similar to the paired secondary forest. Low similarity values were also observed in the paired Guzmán plots, which suggest that the plantations are evolving with species assemblages that are different from those of the secondary forests. Honduran pine vulnerability to wind and implications to plantation forestry The US Forest Service introduced pines to Puerto Rico in 1932 as a plantation species with multiple uses (Briscoe 1959, Francis 2000, Wadsworth 1976). Honduran pines not only yield large volumes of high quality lumber but they are also used Table 2. Sørensen similarity index for various combinations of plantations and paired secondary forests. Comparison Similarity (%) Cubuy pine 2007 vs. 2014 93 Guzmán secondary 2007 vs. 2014 90 Cubuy secondary 2007 vs. 2014 84 Guzmán pine 2007 vs. 2014 79 Cubuy pine 1996 vs. 2007 67 Cubuy pine 1982 vs. 1996 60 Guzmán pine 2014 vs. Guzmán secondary 2014 54 Cubuy pine 2007 vs. Cubuy secondary 2007 45 Guzmán pine 2007 vs. Guzmán secondary 2007 42 Cubuy pine 2014 vs. Cubuy secondary 2014 36 Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 14 for posts, furniture, making paper, ornamental purposes, resins, tannins, fuelwood, rehabilitation of degraded soils, and many other applications. Honduran Pine was planted in many areas globally, including widely throughout the Caribbean, particularly in Jamaica where large-scale plans for a timber-exporting industry were formulated and initiated in the Blue Mountain region (Greig and Foster 1982). The passage of hurricane Allen over the region in 1980 caused extensive reductions in the standing timber on pine plantations and exacerbated attacks of the fungus Fomes annosus (now Heterobasidion annosum (Fr.) Bref.), which causes disease and mortality to pines (Thompson 1983). Thirty percent pine mortality due to this fungus was observed in the first thinning before the hurricane, and the problem increased after the hurricane (Greig and Foster 1982). Subsequent studies demonstrated the susceptibility of Honduran pines to windthrow and to mortality as a result of windstorms in Puerto Rico (Liegel 1982, 1984 b, 1984c; Rodríguez Pedraza 1993; this study), the Dominican Republic (Gannon and Martin 2014), and Central America (Boucher et al. 1990). Our long-term study of paired plantations and secondary forests documented the reduction in the IV of Honduran Pine after the hurricanes and the establishment of non-plantation tree species in the recovering forest stands. The suitability of Honduran Pine as a plantation species is thus diminished in the Caribbean by its vulnerability to hurricane winds, but the importance of the species for forestry purposes remains high because of its many advantages, including rapid growth, low nutrient requirements, growth versatility under varied environmental conditions, high wood quality, and diversity of uses (Francis 2000). Wadsworth (1976) pointed out that even if hurricanes were to affect plantations of Honduran Pine, its wood could be salvaged for other uses, even at the early age of 5 yr. Moreover, ecological research suggests the compatibility of pine plantations with some plant (Lugo 1992, this study) and animal taxa (Collazo and Bonilla Martínez 1988, Cruz 1998, Lugo 1992, Lugo et al. 2012, Mott et al. 2010) and the desirability of using Honduran Pine for the restoration of tree species diversity and productivity on degraded sites to “jump-start” succession (Lugo 1997). Clearly the use of Honduran Pine for whatever purposes must be based on sound silvicultural and ecological precautions as traditionally done by professional foresters, who usually plant pines on degraded lands. Conversion of mature native forests for plantation purposes is usually not recommended. Acknowledgments This study was conducted in collaboration with the University of Puerto Rico. Gisel Reyes contributed to the literature search. The 2014 measurement was conducted in collaboration with Citizens of the Karst. We thank the following colleagues for useful comments to drafts of the manuscript: Ernesto Medina, Tamara Heartsill Scalley, and James Ackerman. Literature Cited Boose, E.R., D.R. Foster, and M. Fluet. 1994. Hurricane impacts to tropical and temperate forest landscapes. Ecological Monographs 64:369–400. Caribbean Naturalist 15 A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 Boucher, D.H., J.H. Vandermeer, K. Yih, and N. Zamora. 1990. Contrasting hurricane damage in tropical rain forest and pine forest. Ecology 71:2022–2024. Briscoe, C.B. 1959. Early results of Mycorrhizal inoculation of pine in Puerto Rico. Caribbean Forester 1959:73–77. Briscoe, C.B. 1962. Early lifting of pine seedlings. Tropical Forest Notes, Institute of Tropical Forestry 3:1–2. Collazo, J.A., and G.I. Bonilla Martínez. 1988. Comparación de la riqueza de aves entre plantaciones de Pino Hondureño (Pinus caribaea) y áreas de bosque nativo en el Bosque Estatal de Carite, Cayey, Puerto Rico. Caribbean Journal of Science 24:1–10. Cruz, A. 1988. Avian resource in a Caribbean pine plantation. Journal of Wildlife Management 52:274–279. Francis, J.K. 1995. Forest plantations in Puerto Rico. Pp. 210–223, In A.E. Lugo and C. A. Lowe (Eds.). Tropical Forests: Management and Ecology. Springer-Verlag, New York, NY, USA. Francis, J.K. 2000. Pinus caribaea Morelet. Pp. 394–403, In J.K. Francis and C.A. Lowe (Eds.). Bioecología de árboles nativos y exóticos de Puerto Rico y las Indias Occidentales. USDA Forest Service, Reporte Técnico General IITF-15, Río Piedras, PR, USA. Gannon, B.M., and P.H. Martin. 2014. Reconstructing hurricane disturbance in a tropical montane forest landscape in the Cordillera Central, Dominican Republic: Implications for vegetation patterns and dynamics. Arctic, Antarctic, and Alpine Research 46:767–776. Greig, B.J.W., and L.E.P. Foster. 1982. Fomes annosus in the pine plantations of Jamaica. The Comonwealth Forestry Review 61:269–275. Holdridge, L.R. 1967. Life-zone ecology. Tropical Science Center, San José, Costa Rica. Liegel, L.H. 1982. Growth, development, and hurricane resistance of Honduras pine in Puerto Rico. Pp. 28–48, In J. González-Liboy and J. Figueroa (Eds.). Noveno simposio de recursos naturales. Departamento de Recursos Naturales de Puerto Rico, San Juan, PR, USA. Liegel, L.H. 1984a. Status, growth, and development of unthinned Honduras Pine plantations in Puerto Rico. Turrialba 34:313–324. Liegel, L.H. 1984b. Assessment of hurricane rain/wind damage in Pinus caribaea and Pinus oocarpa provenance trials in Puerto Rico. Commonwealth Forestry Review 63:47–53. Liegel, L.H. 1984c. Hurricane susceptibility of Pinus caribaea and Pinus oocarpa provenances in Puerto Rico. Pp. 318–319, In R.D. Barnes and G.L. Gibson (Eds.). Provenance and Genetic Improvement Strategies in Tropical Forest Trees. Commonwealth Forestry Institute, Oxford, UK, and Harare, Zimbabwe. Lugo, A.E. 1992. Comparison of tropical tree plantations with secondary forests of similar age. Ecological Monographs 62:1–41. Lugo, A.E. 1997. The apparent paradox of re-establishing species richness on degraded lands with tree monocultures. Forest Ecology and Management 99:9–19. Lugo, A.E. 2008. Visible and invisible effects of hurricanes on forest ecosystems: An international review. Austral Ecology 33:368–398. Lugo, A.E., and J.L. Frangi. 2016. Long-term response of Caribbean palm forests to hurricanes. Caribbean Naturalist Special Issue 1:157–175. Lugo, A.E., and F.N. Scatena. 1996. Background and catastrophic tree mortality in tropical moist, wet, and rain forests. Biotropica 28:585–599. Lugo, A.E., T.A. Carlo, and J.M. Wunderle Jr. 2012. Natural mixing of species: Novel plant–animal communities on Caribbean Islands. Animal Conservation 15:233–241. Caribbean Naturalist A.E. Lugo, C.D. Rodríguez Pedraza, I. Fremont, and I. Vicens 2017 No. 43 16 Mott, B., R.A. Alford, and L. Schwarzkopf. 2010. Tropical reptiles in pine forests: Assemblage responses to plantations and plantation management by burning. Forest Ecology and Management 259:916–925. Rodríguez Pedraza., C.D. 1993. Efectos del huracán Hugo sobre plantaciones y bosques secundarios pareados en el Bosque Experimental de Luquillo, Puerto Rico. Thesis. University of Puerto Rico, Río Piedras, PR, USA. Sørensen, T. 1948. A method of establishing groups of equal amplitude in plant sociology based on similarity of species and its application to analyses of the vegetation on Danish commons. Biologiske Skrifter / Kongelige Danske Videnskabernes Selskab 5:1–34. Thompson, D.A. 1983. Effects of Hurricane Allen on some Jamaican forests. Commonwealth Forestry Review 62:107–115. Wadsworth, F.H. 1976. Prospective environmental significance of pine planting to Puerto Rico. USDA Institute of Tropical Forestry, Rio Piedras, PR, USA. 5 pp. Whitmore, J.L., and L.H. Liegel. 1980. Spacing trial of Pinus caribaea var. hondurensis. USDA Forest Service, Southern Forest Experiment Station Research Paper SO-162. Institute of Tropical Forestry, Rio Piedras, PR, USA. 8 pp. Whittaker, R.H. 1970. Communities and Ecosystems. The Macmillan Company, Toronto, ON, Canada.