The global abundance of tree palms

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests

Long-term thermal sensitivity of Earth’s tropical forests

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

The global abundance of tree palms

Aim: Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location: Tropical and subtropical moist forests. Time period: Current. Major taxa studied: Palms (Arecaceae). Methods: We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results: On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work. Conclusions: Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests

Compositional response of Amazon forests to climate change

Most of the planet's diversity is concentrated in the tropics, which includes many regions undergoing rapid climate change. Yet, while climate-induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether the floristic and functional composition of intact lowland Amazonian forests have been changing by evaluating records from 106 long-term inventory plots spanning 30 years. We analyse three traits that have been hypothesized to respond to different environmental drivers (increase in moisture stress and atmospheric CO2 concentrations): maximum tree size, biogeographic water-deficit affiliation and wood density. Tree communities have become increasingly dominated by large-statured taxa, but to date there has been no detectable change in mean wood density or water deficit affiliation at the community level, despite most forest plots having experienced an intensification of the dry season. However, among newly recruited trees, dry-affiliated genera have become more abundant, while the mortality of wet-affiliated genera has increased in those plots where the dry season has intensified most. Thus, a slow shift to a more dry-affiliated Amazonia is underway, with changes in compositional dynamics (recruits and mortality) consistent with climate-change drivers, but yet to significantly impact whole-community composition. The Amazon observational record suggests that the increase in atmospheric CO2 is driving a shift within tree communities to large-statured species and that climate changes to date will impact forest composition, but long generation times of tropical trees mean that biodiversity change is lagging behind climate change

Sensitivity of South American tropical forests to an extreme climate anomaly

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: Publicly available climate data used in this paper are available from ERA5 (ref. 64), CRU ts.4.03 (ref. 65), WorldClim v2 (ref. 66), TRMM product 3B43 V7 (ref. 67) and GPCC, Version 7 (ref. 68). The input data are available on ForestPlots42.Code availability R code for graphics and analyses is available on ForestPlots42.The tropical forest carbon sink is known to be drought sensitive, but it is unclear which forests are the most vulnerable to extreme events. Forests with hotter and drier baseline conditions may be protected by prior adaptation, or more vulnerable because they operate closer to physiological limits. Here we report that forests in drier South American climates experienced the greatest impacts of the 2015–2016 El Niño, indicating greater vulnerability to extreme temperatures and drought. The long-term, ground-measured tree-by-tree responses of 123 forest plots across tropical South America show that the biomass carbon sink ceased during the event with carbon balance becoming indistinguishable from zero (−0.02 ± 0.37 Mg C ha−1 per year). However, intact tropical South American forests overall were no more sensitive to the extreme 2015–2016 El Niño than to previous less intense events, remaining a key defence against climate change as long as they are protected

Amazon tree dominance across forest strata

The forests of Amazonia are among the most biodiverse plant communities on Earth. Given the immediate threats posed by climate and land-use change, an improved understanding of how this extraordinary biodiversity is spatially organized is urgently required to develop effective conservation strategies. Most Amazonian tree species are extremely rare but a few are common across the region. Indeed, just 227 ‘hyperdominant’ species account for >50% of all individuals >10 cm diameter at 1.3 m in height. Yet, the degree to which the phenomenon of hyperdominance is sensitive to tree size, the extent to which the composition of dominant species changes with size class and how evolutionary history constrains tree hyperdominance, all remain unknown. Here, we use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, midstory and canopy. We further find that, although species belonging to a range of phylogenetically dispersed lineages have become hyperdominant in small size classes, hyperdominants in large size classes are restricted to a few lineages. Our results demonstrate that it is essential to consider all forest strata to understand regional patterns of dominance and composition in Amazonia. More generally, through the lens of 654 hyperdominant species, we outline a tractable pathway for understanding the functioning of half of Amazonian forests across vertical strata and geographical locations

Antillopsyche sessilis Aguila & Davis, 2016, sp. nov.

<i>Antillopsyche sessilis</i> sp. nov. <p> <b>Male</b> (Figure 8). Forewing length: 5.2–6.6 mm.</p> <p> <i>Head</i>: Vestiture white. Antenna 0.3–0.4x length of forewing, 36–43 segmented; scales white; remainder of flagellum brown. Labial palpus entirely white, some individuals with exterior of basal segment brown and scattered scales of the same hue at second segment.</p> <p> <i>Thorax</i>: White. Forewing background shiny cream, with suffusion of pale ochreous scales more concentrated at base; a row of ochreous spots along fold, at apex, and in a transverse band from two-fifths of costa to termen; small darker spots at termen and at basal one fifth of fold; fringe shiny whitish cream. Venter with same pattern but indistinct, basal one fourth of costa brown. Hindwing shiny whitish cream, semitransparent. Legs white, fore and hind tibia hairy, middle tibia with a lateral brush.</p> <p> <i>Abdomen</i>: Vestiture shiny, whitish cream.</p> <p> <i>Genitalia</i>: As described for genus.</p> <p> <b>Female</b> (Figure 9). Forewing length: 8.7 mm. Similar to male except: antenna 0.25x length of forewing. Forewing (partially rubbed) with darker spots extending to base, the dorsal two- thirds of transverse band and the basal half of fold. Frenulum consisting in a cluster of 5 smaller bristles.</p> <p> <i>Abdomen</i>: shiny whitish cream, scaling more dense laterally; corethrogyne scales slightly darker.</p> <p> <i>Genitalia</i>: as described for genus.</p> <p> <b>Larva</b> (Figures 10–20). Maximum length examined 10.2 mm; maximum head width ~ 1.2 mm. Body cuticle dark brown with pinnacula much paler in color. Head: Epicranial notch moderately shallow, ~ half the length of epicranial suture (Figure 14). P1 arising closer to AF2 than A1. AF2 slightly longer than AF1 (Figure 14). Five stemmata present and evenly spaced in an anteriodorsal arch; stemmata 4–5 immediately below 3 (Figure 14). Antenna and maxilla with sensilla as shown (Figures 15 & 17). Labrum with six pairs of dorsal setae, all of moderate length except for elongated M3 and La2; venter of labrum with three pairs of epipharyngeal setae, the two mesal setae only slightly longer than lateral seta (Figures 18–19). Mandible with five cusps which become smaller mesally; lateral margin serrated basal to lateral cusp (Figure 20). Labial palpus with basal segment (1) very elongate, ~ 2/3 the length of spinneret; segment 2 greatly reduced, ~ 0.1 the length of segment 1; apical seta from segment 2 long, ~ 2x the length of segment 2. Spinneret long and slender, gradually tapering to narrow, simple apex. Thorax: Pronotum completely fused with prespiracular pinaculum bearing L1–3 and spiracle; XD1 moderately long, ~ 1.2x the length of XD2 (Figure 13); subventral pinnaculum well developed, extending nearly the length of segment. Dorsal pinnacula of mesothorax fused to form single, light brown plate nearly as large as pronotum; dorsal pinnaculum of metathorax also connected mid-dorsally but divided laterally with SD1 and 2 on lower pinnaculum; lateral pinnacula narrowly separated from notal plates. SV bisetose on T1–3 (Figure 13). Abdomen: D1 and D2 arising from separate oval pinnacula on A1-9 (Figures 12–13); pinnacula bearing D1 on A1 and A2 fused with opposite pinnacula dorsally; pinnaculum of D2 indistinct on A9 (Figures 13 & 16); SD bisetose on A1-8 with SD2 minute, SD2 absent on A9; L series trisetose on A1–9 with L3 arising from separate pinnacula on A1–7, and L1–3 each from separate pinnacula on A8–9 (Figures 13 & 16); SV bisetose on A1-2, 7–9, trisetose on A3–6 (Figure 13). Anal plate with seta D2 absent, represented instead by prominent pore as in <i>Brachygyna</i> (Davis 1999) (Figure 16); prolegs 3–6 with 20–26 crochets in a uniordinnal, lateral penelipse. Anal crochets ~ 21 in a uniordinal row opened caudally. Cuticle surrounding anal aperture thickened but unmodified and similar in texture to remainder of segment.</p> <p> <b>Male pupa</b> (Figures 21–22). Length 5.3–7.0 mm, maximum width 1.3–1.9 mm (n=7). Color amber in smaller individuals, pale reddish brown in larger ones. Wing sheaths reaching anterior margin of abdominal segment A4 (Figure 21). Spiracle of A1 exposed close to hindwing margin. Head with one pair of dorsal setae, one pair on vertex and two pairs on frons; two pairs of dorsal setae on pronotum, mesonotum and abdominal segments A1–A8 (Figure 21); A8 with three additional pairs of setae anterior to cremasteral spines. Venter with SV series bisetose on A4–A6, setae close together and to proleg scars (Figure 22); A8 with four pairs of setae: two near anterior margin, one posterior to protuberances and one on ridge edges of ventral pair of cremasteral spines (Figure 22). Dorsum of abdomen with a single row of posterior oriented spines on anterior margin of A4–A8 and a single row of anterior oriented spines on posterior margin of A3–A5 (Figure 22, Table 1). Cremaster consisting of a pair of adjacent round tubercles at middle of segment and two pairs of small spines, one pair directed ventrally and the other, at apex, directed caudad; anal groove indistinct.</p> <p> <b>Female pupa</b>. Length 8.5–9.4, maximum width 2.2–2.4 (n=2). Similar to male except: abdomen enlarged; average number of spines on dorsum of abdomen larger, spines absent from anterior margin of A8 or represented by a single large spine with a broad base (Table 1).</p> <p> <b>Larval case</b> (Figures 23–24). Brown, cylindrical; largest case 31 mm in length, 4 mm in diameter; walls soft, covered externally with fecal pellets and minute fragments of bark and fungi, lined internally with dense grayish white silk.</p> <p> <b>Type material.</b> Holotype: ♂, CUBA: Granma, Bartolomé Masó, La Aguada de Joaquín, 1300 m, 2.xii.2007, ex <i>Corticium</i> sp., emerged 24.i.2008, <i>(R. Núñez)</i> (CZACC). Paratypes: 6 ♂, 1 ♀. 3 ♂, same data as holotype except: emerged 23.i.2008, 24.i.2008, and 8.ii.2008, ex <i>Corticium</i> sp., ex <i>Phylloporia pectinata</i>, and <i>Trametes villosa</i>. ♀, same data as holotype except: 12.ii.2007, ex <i>Corticium</i> sp., ex <i>Phylloporia pectinata</i>, and <i>Trametes villosa</i>; emerged 25.iii.2007, <i>(R. Núñez & E. Fonseca)</i>. 3 ♂, same data as anterior except: emerged 24.iii.2007, emerged 4.iv.2007, emerged 5.iv.2007. 3 larval cases with associated pupal exuviae or pupal remains, CUBA: Granma, Bartolomé Masó, camino al Pico Turquino, alrededores de La Platica, 1000 m, 22.vii.2009, <i>(R. Núñez)</i> (CZACC, USNM).</p> <p> <b>Hosts</b> (Figures 23–24). Corticiaceae: <i>Corticium</i> sp.; Polyporaceae: <i>Trametes villosa</i> Fr. (Kreisel) (Figure 23); Hymenochaetaceae: <i>Phylloporia pectinata</i> (Klotzsch) Ryvarden (Figure 24).</p> <p> <b>Distribution</b> (Figure 25). Known only from three adjacent montane localities in the Sierra Maestra of southeastern Cuba.</p> <p> <b>Etymology</b>. The specific name is derived from the Latin <i>sessilis</i> (sitting) in reference to the sedentary feeding behavior by the larva of this species, unusual among known Psychidae.</p> <p> <b>Habitat</b>. <i>Antillopsyche sessilis</i> inhabits the rainforests and evergreen forests at intermediate elevations, 1000– 1300 m. The relative humidity of this region is between 87 and 92% in the morning (7:00 am) and between 75 and 80% in the afternoon (1:00 pm) (Montenegro 1991). The precipitation is between 1,800 and 2,300 mm per year. Average annual temperature varies between 16 and 20ºC. January average temperatures fluctuate between 14 and 18ºC, and July temperatures between 18 and 22ºC.</p> <p> <b>Flight period</b>. Reared specimens emerged from January to April. Because data are from only two collections (February and December) there is little to report on seasonal occurrence. However, high humidity and relative low temperatures of habitat through the year probably provide suitable conditions for development in every month.</p> <p> <b>Biological observations</b>. The species feeds on a wide variety of fungal hosts. On one standing dead tree at La Aguada de Joaquín, several larvae were found feeding on the three hosts mentioned above. The larval feeding behavior of <i>A. sessilis</i> differs from that commonly found throughout the Psychidae in being more restricted and attached to a specific site. They probably also feed inside the fungi but it seems to occur only during the initial stages. Even larvae with cases directly attached to fungi were observed eating on the external surface (Figure 24). This may be a strategy to obtain food when it is scarce by increasing the foraging area for each individual, as shown Fig. (23) where one larva is feeding on a trunk with all <i>Trametes villosa</i> almost completely devoured. The larva tunnels into fungus and/or wood and firmly attaches the case to the entrance. The interior of the case and the tunnel substrate are covered with the same continuous silk layer. All cases with living individuals were found on standing dead trunks (Figure 26). A small group of old empty cases was collected on a fallen dead trunk a few inches above the ground. The distance from the ground of all observed or collected specimens varied between 0.5 to 2.5 meters.</p> <p>Larvae were observed feeding both during the day and night in nature and in the laboratory. Larvae were not observed feeding at the proximal (anterior) end of case as do nearly all other Psychidae. Instead, they are in an inverted position and foraging at the distal end of the case onto the external surface of the tree trunk (left arrow in Figure 26). When disturbed, the larvae retreat rapidly to the safety of the tunnel within the trunk.</p> <p> Before pupation, the larva closes the distal end with silk forming a slit-like opening by flattening the transverse section of the case. Although the exact site of pupation was not observed, it seems to occur inside the tunnel or outside close the entrance. The reason for this uncertainty is that two larval cases were bent at the distal two-fifths after pupation and both adults emerge from the angle (left case at Figure 27). Thus, pupation probably occurs at least in one of the two locations suggested above. The bending of the case may have been caused by a species of <i>Dryadaula</i> (Dryadaulidae) (Figure 28). Only a single female of <i>Dryadaula</i> emerged few days prior to the emergence of the <i>A. sessilis</i> adult, from one of the two bent cases.</p> <p>The pupal stage requires 32 to 42 days (n=3) and emergence occurs shortly after sunset (8:00 to 9:00 pm, n=3). Although night collecting with mercury vapor lights was conducted at both localities, no adults were observed or collected. A 250-watt bulb on a sheet was used during 12 nights between January 2005, February 2007 and November 2007 at La Aguada de Joaquín. This method was followed at La Platica, a small village just 300 m away from the light collecting locality, during 20 nights (January 2005, February 2007, November 2007, August 2008, May 2009 and July 2009) without the sighting or collecting of a single specimen.</p> <p> Larvae collected at La Aguada de Joaquín were attacked by parasitoids. Several wasps emerged from two larvae were identified as a species of <i>Baryscapus</i> Förster, 1856 (Eulophidae: Tetrastichinae) (Figure 29).</p>Published as part of <i>Aguila, Rayner Núñez & Davis, Don R., 2016, Antillopsyche sessilis, new genus and species, a new Psychidae (Lepidoptera: Tineoidea) from Cuba with an unusual larval feeding behavior in Zootaxa 4066 (1)</i>, DOI: 10.11646/zootaxa.4066.1.3, <a href="http://zenodo.org/record/262609">http://zenodo.org/record/262609</a&gt

Antillopsyche Aguila & Davis, 2016, gen. nov.

<i>Antillopsyche</i> gen. nov. <p> <b>Type species</b>. <i>Antillopsyche sessilis</i>, new species <b>Male</b>. Forewing length: 5.2–6.7 mm.</p> <p> <i>Head</i> (Figure 1): Vestiture of frons semi-erect, moderately rough; scales relatively broad, apices bi- to quadridentate; scales of vertex elongated, more rough, with a low ridge of scales curling down toward frons between antennae; occiput with a pair of erect tufts of slender scales with bidentated apices. Eye large, interocular index 1.4. Ocelli absent. Antenna 0.3–0.4x length of forewing, 36–43 segmented, serrated ventrally almost to apex, serrations less than 0.5x the diameter of segment; scape smooth ventrally, without scales or setae; scales of dorsum rough, anterior margin with long bidentated scales curling down toward eyes; basal third of flagellum with a dorsal row of broad scales with tri to quadridentate apices on each segment; remainder of flagellum naked; sensillia dense, 0.5x diameter of flagellomere in length, each segment also bearing two pair of longer bristles, about 1.5x the diameter. Haustellum reduced, about half the length of second segment of labial palpus. Maxillary palpus consisting of two short segments, 0.4–0.5x length of haustellum. Labial palpus upcurved, 3-segmented; vestiture smooth; segments ratio from base: 1.0: 1.5: 0.75.</p> <p> <i>Thorax</i>: Vestiture smooth. Forewing relatively broad, width/length (W/L) index 0.37–0.42, apex evenly rounded; radius 3-branched, Rs2 and Rs3 completely fused ending above wing apex; Rs3+4 fused, extending to wing apex; accessory cell absent; base of M simple within discal cell (Figure 2). Hindwing shorter and slightly more slender than forewing, W/L index 0.33–0.39; base of M simple within discal cell; vein 1A+2A sinuated; frenulum consisting in a single large bristle (Figure 2). Foreleg with epiphysis well developed, approximately 0.5 length of tibia, spinose on inner surface; tibial spur pattern 0-2-4.</p> <p> <i>Abdomen</i>: Eighth sternum with apodemes of anterolateral angles present but greatly reduced, apices blunt (Figure 3). Sternum 8 with a pair of small slender coremata present on each side.</p> <p> <i>Genitalia</i> (Figures 4–6): Tegumen moderately slender and elongated, lightly sclerotized; caudal margin shortly bilobed. Vinculum-saccus V-shaped. Apotheca absent. Anellar tube membranous, cylindrical, and firmly enclosing aedeagus; juxta undeveloped. Valva moderately broad, divided into a large, setose dorsal lobe (cucullus) and a smaller broad ventral lobe (saccullus); apex of saccullus round without processes, bearing 16–23 short spines. Aedeagus cylindrical, straight; vesica not permanently extruded.</p> <p> <b>Female</b>. Forewing length: 8.7 mm. Similar to male except antenna 0.25x length of forewing. Frenulum consisting in a cluster of 5 smaller bristles.</p> <p> <i>Abdomen</i>: Seventh segment entirely encircled by dense whitish to creamy corethrogyne scales.</p> <p> <i>Genitalia</i> (Figure 7): Ovipositor greatly extended and with three pairs of apophyses; posterior apohyses the longest, ~ 2x the length of anterior apophyses and ~ 3x the length of accessory apophyses. Caudal margin of lamella antevaginalis approximately truncate; ostium not extended, instead flush with eighth sternum. Bursa copulatrix not examined (lost in dissection).</p> <p> <b>Etymology.</b> The generic name is derived from antillae, the Latin word for Antilles, the archipelago where this taxon occurs, and the Greek <i>psyche</i> (butterfly, spirit, life) in reference to the West Indian distribution of the only known member of this psychid genus.</p>Published as part of <i>Aguila, Rayner Núñez & Davis, Don R., 2016, Antillopsyche sessilis, new genus and species, a new Psychidae (Lepidoptera: Tineoidea) from Cuba with an unusual larval feeding behavior in Zootaxa 4066 (1)</i>, DOI: 10.11646/zootaxa.4066.1.3, <a href="http://zenodo.org/record/262609">http://zenodo.org/record/262609</a&gt