Plant communities of perennial succulents in the Caspian Lowland
Six plant communities of the class Salicornietea fruticosae Br.-Bl. et R. Tx. ex A. Bolòs y Vayreda 1950 registred in the northern part of the Caspian Lowland: basal communities Halocnemum strobilaceum–[Salicornietea fruticosae], Halocnemum strobilaceum–[Thero-Salicornietea–Salicornietea fruticosae] and Halocnemum strobilaceum–[Artemisio santonici–Puccinellion fominii], subass. Puccinellio fominii–Halimionetum verruciferae limonietosum suffruticosi Shelyag-Sosonko et al. 1989 and also two new associations — Suaedo confusae–Kalidietum caspici and Suaedo corniculatae–Halimionetum verruciferae are described in the paper.
The 2 new associations, Carici stantis—Salicetum reptantis and Salico-Polemonietum acutiflori, are described within the all. Caricionstantis of the class Scheuchzerio-Caricetea fuscae R. Tx. 1937 for the northern belt of the typical tundra subzone of Taymyr. The diagnostic species group of the first syntaxon includes plants typical of sites with excessive watering. The ass. Carici stantis—Salicetum reptantis is restricted to bottoms or lower parts of the watershed and mountain terrace slopes. The ecological regime of these sites is subject to slight variations reflected in presence/ absence of certain species. Due to floristic differences, the association is subdivided into several subassociations which form a topographic-ecological series along the humidity gradient: epilobietosum palustris→ptilidietosum ciliaris→typicum→petasitetosum frigidi. The ass. Carici stantis—Salicetum reptantis is referred to the all. Caricionstantis which also includes the associations Meesiotriquetris—Caricetumstantis and Pooarcticae—Dupontietumfisheri (also described from the Ragozinka R. basin); the latter occur in the wet depressions between sloping hills and the flowing valleys, respectively. If compared to these two, the ass. Carici stantis—Salicetum reptantis is shown to hold an intermediate position between them. The ass. Salico-Polemonietum acutiflori with the 2 variants, Salix lanata and S. reptans, represents various variants of mire vegetation which have undergone zoogenic transformation (by lemmings). The stands size 1—1.5 m2 in space. The diagnostic species group comprises plants common of the wet mossy stream banks. The association is referred to the all. Caricion stantis, although many diagnostic species of the alliance are not present in its composition. When the new data are available, the association is probable to be separated into an independent alliance.
The results of syntaxonomical studies of psammophyte vegetation of the Chara sands (Verkhnecharskaya depression Zabaikalsky Krai) are presented. Plant communities on open sands belong to the class Brometea korotkyi Hilbig et Korolyuk 2000 and to the order Oxytropidetalia lanatae Brzeg et Wika 2001. The new alliance Aconogonion chlorochryseum is established. 4 new associations, 3 new subassociations and 2 communities are characterized.
3 new associations, distributed in the Southern Nechernozemie of Russia, are described for the first time with use of the Braun-Blanquet approach: Poo angustifoliae–Arrhenatheretum elatioris, Festuco pratensis–Leucanthemetum vulgaris, Trifolio arvensi–Rumicetum thyrsiflori. The synecological amplitudes of humidity, acidity and soil richness by mineral nitrogen of the associations are defined. Communities of ass. Poo angustifoliae–Arrhenatheretum elatioris are distributed on the flat slopes of ravines on the dry, subacidic, grey wood loamy soils moderately rich by mineral nitrogen. Communities of ass. Festuco pratensis–Leucanthemetum vulgaris are distributed on fresh, subacidic, rather poor in mineral nitrogen grey and dark grey wood loamy soils on the fallow lands of various age within landscapes of loess plateau; on sod-podzolic loamy, sandy and subsandy soils within landscapes of fluvioglacial loamy and moraine-outwash plains. They can meet occasionally on grey wood loamy soils. Communities of the Potentilla argentea var. are distributed on grey and dark grey wood loamy soils on the fallow lands within landscapes of loess plateau. Communities of the Medicago lupulina var. are distributed on sod-podzolic loamy, sandy and subsandy subacidic, rather poor in mineral nitrogen soils on the fallow lands of various age. They may occur in the small sites on the continental meadows or along highways. Occasionally these plant communities can be found on grey wood loamy soils. Communities of ass. Trifolio arvensi–Rumicetum thyrsiflori are distributed on raised sites on gentle-wavy outwash or moraine-outwash plains on dry and moderately sour, poor by mineral nitrogen easily sandy and sandy podzol soils. For the estimation of a homotoneity of established syntaxa the index of homotoneity of H.Passarge (1979) is used. The ass. Poo angustifoliae–Arrhenatheretum elatioris is characteristic by the high homogenetic variability. Totally, association’s index of homotoneity is high — 0.52. The low index of a homotoneity is characteristic for аss. Festuco pratensis–Leucanthemetum vulgaris — 0.35, for the Potentilla argentea var. — 0.33 and Medicago lupulina var. — 0.44. Following associations have a low index of the homotoneity: аss. Trifolio arvensi–Rumicetum thyrsiflori — 0.33, as in subass. T.a.–R.th. typicum— 0.33, and in subass. T.a.–R.th. helichrysetosum arenarii — 0.44. Such low indexes of a homotoneity are characteristic for semiruderal and serial communities.
AbstractAn overview of the salt-marsh herbland and scrub vegetation belonging to the class Salicornietea fruticosae Br.-Bl. et Tx. ex A. Bolòs y Vayreda 1950 in Apulia is presented. Data available from literature have been supplemented with original relevés performed in different locations of the Apulia region. On the basis of a total of 297 relevés, fifteen communities have been defined, according to the traditional phytosociological system based on dominant and/or diagnostic taxa. For comparison purposes, the salt-marsh vegetation has been classified using numerical methods. The results obtained show that most of the clusters correspond to specific associations, and confirm the division into vegetation alliances and orders. Numerical analysis also allowed us to assign the proper allocation of some associations and plant communities drawn from literature. Five alliances, with plant communities characterized by specific ecological features, have been discriminated: Sarcocornion alpini and Arthrocnemion glauci (lower marshes), Salicornion fruticosae (middle marshes), Inulion crithmoidis and Suaedion brevofoliae (upper marshes). In addition, during the field work, a population of Halocnemum strobilaceum (Arthrocnemo-Halocnemetum strobilacei), new record for the Apulia region, has been found.
A phytosociological analysis and synopsis of the dry woodlands and succulent vegetation of the Peruvian Andes
ABSTRACT A phytosociological approach to dry forest and cactus communities on the occidental slopes of the Peruvian Andes is presented in base of 164 plots carried out following the Braun-Blanquet method. From them, 52 have been made recently, and the other 112 were taken from the literature. After a multivariate analysis, using a hierarchical clustering and a detendred correspondence analysis, the Acacio-Prosopidetea class (dry forest and cactus communities, developed on soils with some edaphic humidity or precipitations derived from El Niño Current), the Opuntietea sphaericae class (cactus communities of central and southern Peru, on few stabilized rocky or sandy soils) and the Carico-Caesalpinietea class (dry forests of the Peruvian coastal desert, influenced by the maritime humidity of the cold Humboldt Current), are differentiated. Within the Acacio-Prosopidetea class, two alliances are commented: the Bursero-Prosopidion pallidae (with two new associations Loxopterygio huasanginis-Neoraimondietum arequipensis and Crotono ruiziani-Acacietum macracanthae), and the new alliance Baccharido-Jacarandion acutifoliae (with the new associations Armatocereo balsasensis-Cercidietum praecocis and Diplopterydo leiocarpae-Acacietum macracanthae). For the Opuntietea sphaericae class, the association Haageocereo versicoloris-Armatocereetum proceri (Espostoo-Neoraimondion) is described on the basis of plots from hyperarid localities of central Peru. Finally, a typological classification of the studied plant communities is given.
Classification of the petrophytic steppe communities occurring on unique geomorphological formations of the Southern Urals (Bashkortostan Republik) — palaeoreefs (”shikhans“) have been performed. The plant communities were classified and included into two new associations (Minuartiо krascheninnikovii―Festucetum pseudovinae и Trinio muricatae―Centauretum sibiricae). Ecological, geographical, floristic and phytocoenotic characteristics of the syntaxa are discussed.
We have performed the phytoecological mapping of the Northern Caspian Region in scale 1 : 2 500 000. The territory includes the Caspian Lowland and the Mangyshlak Peninsula between 45°-53°30 E and 49°-42° N. The earlier published maps of the same scale showed either vegetation of the Caspian Lowland or that of the Mangyshlak Peninsula. We have shown both territories on one map, which has permitted to reflect the peculiar features of the Northern Caspian Region: extensive distribution of the dwarf-semishrub communities not only in desert but also in the steppe zone; differences of desert vegetation cover between areas west and east of the Ural River; the running of zonal steppe/desert boundary along 44° N on the west coast of Caspian Sea whereas on the east coast the middle deserts occur at the same latitude: etc. Our studies were based upon a broad understanding of the desert and steppe types of vegetation. To the desert type of vegetation on the plains of Caspian Region and Turan belong the communities of xerophilous and hyperxerophilous micro- and mesothermic plants of various growth forms, mostly dwarf-semishrubs, semishrubs and shrubs, to the steppe type - plant communities consisting mostly of perennial more or less microthermic xerophilous herbaceous plants, predominantly of bunchgrasses, locally tufted sedges and perennial herbs. One should add that stony-rubble and salted substrates in steppe zone are characterized by distribution of dwarf-semishrub communities. Some researchers, apart from steppe and desert zones distinguish semidesert one in the Caspian Lowland, however it is accepted that there is no semidesert type of vegetation. Therefore it is difficult to agree with the recognition of the semidesert zone. The drawing of zonal boundary between steppe and desert in the Northern Caspian Region involves definite difficulties depending on environmental features of the region and strong anthropogenic press. So, on sand massifs and saline soils vegetation is the same both in desert and steppe zones. Vegetation cover of the Western Caspian Region is transformed considerably under anthropogenic influence. It is known that in steppe region at ploughing up of the worm- wood-bunchgrass steppes one of the stages of restoration of fallow lands is the wormwood one, physiognomically similar to desert. The same appearance is assumed by steppe at the strong grazing when grasses are destroyed and wormwoods is growing up. Such anthropogenic wormwood communities are widely spread at the boundary between zones. This resulted in that on earlier published vegetation maps the desert zone in the interfluve of Volga-Ural was shifted fairly far to the North up to 49°N. At present we believe that it is possible to assign the northern part of Ryn-Sands to steppe zone and to draw the zonal boundary along the latitude of 48°30 N. The boundary is determined by climate, geological history, hydrology, edaphic conditions and. vegetation. Somewhat differently than earlier we draw the zonal boundary in the Caspian Lowland between the Volga River and the Ergeni Height. It goes from Prishib's settlement to south-west to Yashkul's settlement (45°30 E) and further westward of Achinery's settlement to south-east up to the Kuma River. We could specify its position since during the last years the part of fallow lands, occupying large areas to the west and north of this line, restored up to steppes of Stipa sareptana-Artemisia lerchiana and those of Agropyron desertorum-Artemisia lerchiana. In the course of cartographic works we compiled the vegetation map of the Northern Caspian Region. This map became the base for series of maps: phytoecological one. the map of dominating plant formations, the map of edaphic variants of plant communities, the map of transformation of ecosystems of the Lower Volga Region. Phytoecological map (Fig. 1) gives an idea of latitudinal differentiation of vegetation in the Northern Caspian Region which depends on climate, and reflects its interrelation with soil conditions on plains and with lithological composition in low mountains. The map of edaphic variants of plant communities (Fig. 2) well reflects the peculiar features of various parts of the Northern Caspian Region: between the Terek River and the Ural River psammophyte and hemipsammophyte variants there predominate; east of the Ural River halophyte ones prevail: on the Mangyshlak Peninsula all variants are represented. Pelitophyte variants predominate in the west of the Region and along its northern margin within the limits of steppe zone. On the map of dominating formations (Fig. 3) we could show the distribution of 17 formations and 1 group of formations. A part of formations is restricted exclusively to steppe zone or desert zone, another part is spread throughout the both. This map helps to understand such peculiar feature of the region as wide distribution of dwarf-semishrub communities not only in deserts but also in steppes, which is due to presence of large areas of sands and saline soils in region. The Caspian Region was intensively used by man for a long time. By present time vegetation cover is noticeable transformed. We tried to show cartographically the degree of this transformation and differences in economical utilization of the Lower Volga area (Fig. 4). 4 degrees of transformation are distinguished: Tl-weak, T2-moderate, T3-strong, T4-very strong. Each polygon is considered from standpoint of type of anthropogenic influence: such as pastures (index «a»), fallow lands (index «b»). For pastures degree of grazing is recorded - from weak grazing to overgrazing. For fallow lands the stage of restoration is detected: from the tall weed one up to the perennial herb one conventionally restored.
Español. El departamento de Cajamarca, en el Norte del Perú, se caracteriza en general por un clima más húmedo que el resto del territorio andino peruano occidental. Teniendo en cuenta el paralelismo entre el clima y las unidades de vegetación que ofrecen los pisos bioclimáticos, los ombrotipos, la geología y los suelos, y levantando inventarios según la metodología de Braun-Blanquet, estudiamos la vegetación de este territorio. Se describen 2 comunidades vegetales, 8 asociaciones, 3 subasociaciones, 3 alianzas, 1 orden y 1 clase fitosociológica. Como resultado, se analizan la comunidad de Cecropia montana y Heliocarpus americanus (termotropical subhúmedo-húmeda) y de Muntingia calabura y Hura crepitans (infratropical seco-subhúmeda), ambas de la clase Nectandro laevis-Licarietea canellae presente en el norte del territorio. Hacia el sur, los bosques lauroides y esclerófilos están representados por las nuevas asociaciones Axinaeo nitidae-Podocarpetum oleifolii (bosques mesotropicales, húmedo-hiperhúmedos), Verbesino auriculigerae-Siparunetum muricatae (bosques mesotropicales húmedo-hiperhúmedos de áreas alteradas), Berberido beauverdianae-Myrcianthetum myrsinoidis (bosques del piso mesotropical inferior seco-subhúmedo) y Aristeguietio discoloris-Kageneckietum lanceolatae (bosques del piso mesotropical superior seco-subhúmedo), todas agrupadas en la nueva alianza Monnino pilosae-Myrcianthion myrsinoidis (Pruno rigidae-Oreopanacetea floribundi). Las asociaciones nuevas Baccharito latifoliae-Monactinetum flaverioidis (supra-mesotropical subhúmedo-seca) y Monactino flaverioidis-Colignonietum parviflorae (mesotropical húmeda) son las arbustedas sucesionales de los bosques y se agrupan en la alianza Otholobio munyensis-Rubion robusti all. nova y en la nueva clase andina Clematido peruvianae-Baccharitetea latifoliae. Se describen dos nuevas asociaciones de los pajonales del páramo (“jalca”) con sus subasociaciones: Calamagrostio tarmensis-Hypericetum laricifolii (pajonales supratropicales húmedos del sector Chota-Contumazá), con la subasociación cortaderietosum nitidae en áreas rocosas, y Agrostio tolucensis-Paspaletum bonplandiani (pajonales orotropicales húmedos-hiperhúmedos del sector Chota-Contumazá), con la subasociación puyetosum fastuosae en suelos húmedos, y calamagrostietosum curvulae como una subasociación de transición hacia los pajonales de la puna del centro del Perú. Además, hemos reconocido y lectotipificado la asociación supratropical húmeda Oreobolo goeppingieri-Hypericetum laricifolii, característica del sector biogeográfico Loja-Cutervo. Todas estas asociaciones de pastizales pertenecen a la nueva alianza Agrostio tolucensis-Paspalion bonplandiani y al nuevo orden Agrostio tolucensis-Paspaletalia bonplandiani (Calamagrostietea vicunarum). Por otra parte, presentamos un esquema sintaxonómico con todas las clases fitosociológicas estudiadas por el momento en el departamento de Cajamarca, incluyendo bosques secos y vegetación con cactus y otras plantas suculentas (Acacio macracanthae-Prosopidetea pallidae), alisedas (Alnetea acuminatae), bosques altoandinos (Polylepidetea tarapacano-besseri), y vegetación helofítica de riveras (Tessario integrifoliae-Baccharitetea salicifoliae). Como resultado de este estudio fitosociológico comentamos la biogeografía del N del Perú estableciendo los sectores Loja-Cutervo y Chota-Contumazá, y finalmente hemos cartografiado la vegetación potencial de Cajamarca English. The Department of Cajamarca, in Northern Peru, is generally characterized by a more general humid climate that in the rest of the occidental Andean Peruvian territory. Taking account of the parallelism between climate and vegetation units offered by bioclimatic belts and ombrotypes, geology and soils, and making plots according to the Braun-Blanquet methodology, the vegetation of the territory was studied. Two plant communities, 8 associations, 3 subassociations, 3 alliances, 1 order and 1 phytosociological class are described. As a result, we have analyzed the Cecropia montana and Heliocarpus americanus (thermotropical subhumid-humid) and the Muntingia calabura and Hura crepitans (infratropical dry-subhumid) plant communities, both belonging to the Nectandro laevis-Licarietea canellae class in the North of the territory. To the South, laurel like and sclerophyllous forests are represented by the new associations Axinaeo nitidae-Podocarpetum oleifolii (mesotropical, humid-hyperhumid forests), Verbesino auriculigerae-Siparunetum muricatae (mesotropical humid-hyperhumid forests on disturbed areas), Berberido beauverdianae-Myrcianthetum myrsinoidis (lower mesotropical dry-subhumid forests), and Aristeguietio discoloris-Kageneckietum lanceolatae (upper mesotropical dry-subhumid forests), all grouped into the new alliance Monnino pilosae-Myrcianthion myrsinoidis (Pruno rigidae-Oreopanacetea floribundi). The supra-mesotropical, subhumid-dry Baccharito latifoliae-Monactinetum flaverioidis and the mesotropical humid Monactino flaverioidis-Colignonietum parviflorae new associations are the successional shrublands of the forests, grouped into the new alliance Otholobio munyensis-Rubion robusti and into the new Andean class Clematido peruvianae-Baccharitetea latifoliae. Two new associations for the paramo (“jalca”) grasslands have been described with their subassociations: Calamagrostio tarmensis-Hypericetum laricifolii (supratropical humid grasslands from the Chota-Contumazá biogeographical sector), with cortaderietosum nitidae subassociation on rocky areas, and Agrostio tolucensis-Paspaletum bonplandiani (orotropical humid-hyperhumid grasslands from the Chota-Contumazá biogeographical sector), with puyetosum fastuosae subassociation on humid soils, and calamagrostietosum curvulae as transitional subassociation to the puna grasslands in Central Peru. Furthermore, we have recognized and lectotypified the supratropical humid association Oreobolo goeppingieri-Hypericetum laricifolii from the Loja-Cutervo biogeographical sector. These grassland associations belong to the new alliance Agrostio tolucensis-Paspalion bonplandiani and to the new order Agrostio tolucensis-Paspaletalia bonplandiani (Calamagrostietea vicunarum class). Besides, we present a syntaxonomical scheme with all the phytosociological class studied for the moment in the Department of Cajamarca, including dry forest and succulent vegetation with cactus (Acacio macracanthae-Prosopidetea pallidae), Andean alder forests (Alnetea acuminatae), high Andean forests (Polylepidetea tarapacano-besseri), and helophytic river vegetation (Tessario integrifoliae-Baccharitetea salicifoliae). As a result of the study of the phytosociological units of Cajamarca, we comment the biogeography of Northern Peru establishing the Loja-Cutervo and Chota-Contumazá sectors, and finally, we have maped the potential vegetation of Cajamarca.
RESUMEN. Nuevas observaciones sobre la vegetación del Sur del Perú. Del Desierto Pacífico al Altiplano. En este trabajo, aportamos novedades sobre la vegetación del S del Perú desde el Desierto Pacífico a las cumbres del Altiplano. Como resultado se describen 19 asociaciones distribuidas entre diferentes formaciones vegetales: arbustedas y bosques climácicos de la costa [Echinopsio chalaensis-Randietum armatae (arbustedas espinosas termotropicales semiáridas), Caesalpinio spinosae-Myrcianthetum ferreyrae (bosques termotropicales secos)], vegetación herbácea de las lomas costaneras [Nolano spathulatae-Palauetum dissectae (herbazales de suelos arenosos poco estabilizados), Hoffmannseggio mirandae-Palauetum weberbaueri (herbazales de suelos arenosos estabilizados)], vegetación de los saladares de la costa [Cresso truxillensis-Distichlietum spicatae (comunidad de suelos arenosos y salinos), Cypero laevigati-Distichlietum spicatae (vegetación de suelos húmedos salinos), Lippio nodiflorae-Paspaletum vaginati (pastizales de las costa pacífica inundados por aguas salobres), Schoenoplectetum olneyi-americani (juncales de la costa pacífica), Sporobolo virginici- Distichlietum spicatae (pastizales de la costa)], monte ribereño de la costa [Plucheetum absinthioidis (arbustedas halófilas)], comunidades de freatófitos de las quebradas [Acacio macracanthae-Tecometum guarumis (asociación termo-mesotropical de freatófitos del departamento de Ica), Schino mollis-Tecometum arequipensis (asociación termo-mesotropical de freatófitos del SE del departamento de Arequipa y NO del de Moquegua), Schino mollis-Tecometum tanaeciiflorae (asociación termo-mesotropical de freatófitos de las quebradas del río Colca)], comunidades de cactáceas columnares [Armatocereo riomajensis-Euphorbietum apurimacensis (vegetación de cactus y arbustos de Euphorbia, mesotropical semiárida del cañón del Colca en Arequipa), Weberbauerocereo rahuii-Browningietum candelaris (vegetación de cactus, termotropical árida de los valles del Cotahuasi, Colca y Siguas en Arequipa), Weberbauerocereo rahuii-Corryocactetum brevistyli (vegetación de cactus, mesotropical árida-semiárida de los cañones del Cotahuasi y Colca) y Weberbauerocereo torataensis-Corryocactetum brevistyli (vegetación de cactus, mesotropical árida del valle de Torata en Moquegua)], vegetación rupícola [Polyachyro sphaerocephali-Puyetum densiflorae (comunidades rupícolas supratropicales del cañón del Colca en Arequipa)], y pajonal-tolares y puyales [Baccharido tricuneatae-Puyetum raimondii (comunidades con Puya raimondii orotropicales subhúmedas), Diplostephio108A. Galán de Mera et al.tovari-Festucetum orthophyllae (pajonal-tolares orotropicales seco-subhúmedos de valles interandinos)]. Además se describen 4 alianzas y 3 órdenes [Grindelion glutinosae y Citharexylo flexuosi-Crotonetalia alnifolii (arbustedas y bosques de las lomas del S del Perú), Ludwigio octovalvis-Paspalion vaginati y Schoenoplectetalia olneyi-americani (pastizales y juncales del Desierto Pacífico), Plucheion absinthioidis (arbustedas costeras del sector Arequipeño), y Sarcocornio neei-Distichlion spicatae y Sarcocornietalia neei (vegetación de los saladares de la costa pacífica peruana y chilena)], y 1 clase fitosociológica [Carico candicantis- Caesalpinietea spinosae (bosques y arbustedas termo-mesotropicales seco-semiáridos andinas occidentales]. También se presenta un esquema sintaxonómico comentado con todas las unidades fitosociológicas reconocidas hasta el momento en el S del Perú.Palabras clave. Vegetación, sintaxonomía, sur del Perú.ABSTRACT. New observations about the vegetation of Southern Peru. From the Pacific Desert to the high Andean plateau. In this work, we present new reports about the vegetation of southern Peru, from the Pacific Desert to the highland of the Altiplano: As result, 19 new associations distributed in different plant formations are described: coastal shrublands and climax forests [Echinopsio chalaensis-Randietum armatae (semiarid thermotropical spiny schrubs), Caesalpinio spinosae-Myrcianthetum ferreyrae (dry thermotropical forests)], herb communities of the coastal hills [Nolano spathulatae-Palauetum dissectae (herbs on low stabilized sandy soils), Hoffmannseggio mirandae-Palauetum weberbaueri (herbs on stabilized sandy soils)], coastal vegetation on salt soils [Cresso truxillensis-Distichlietum spicatae (plant community on salt and sandy soils), Cypero laevigati-Distichlietum spicatae (vegetation on humid salt soils), Lippio nodiflorae- Paspaletum vaginati (grasslands of the Pacific Coast flooded by salt waters), Schoenoplectetum olneyi- americani (Rushes of the Pacific Coast), Sporobolo virginici-Distichlietum spicatae (coastal grasslands)], coastal riverside shrublands [Plucheetum absinthioidis (halophilous shrub communities)], freatic plant communities of the ravines [Acacio macracanthae-Tecometum guarumis (freatic thermo-mesotropical association of Ica department), Schino mollis-Tecometum arequipensis (freatic thermo-mesotropical association of SE Arequipa and NW Moquegua departments), Schino mollis-Tecometum tanaeciiflorae (freatic thermo-mesotropical association of the affluents of the Colca river in Arequipa)], columnar cactus plant communities [Armatocereo riomajensis-Euphorbietum apurimacensis (semiarid mesotropical cactus and Euphorbia-shrubs vegetation of the Colca canyon in Arequipa), Weberbauerocereo rahuii-Browningietum candelaris (arid thermotropical cactus vegetation of the Cotahuasi, Colca and Siguas valleys in Arequipa), Weberbauerocereo rahuii-Corryocactetum brevistyli (arid-semiarid mesotropical cactus vegetation of the Cotahuasi and Colca canyons in Arequipa) and Weberbauerocereo torataensis-Corryocactetum brevistyli (arid mesotropical cactus vegetation of the Torata valley in Moquegua), rock plant vegetation [Polyachyro sphaerocephali-Puyetum densiflorae (supratropical rock plant communities of the Colca canyon in Arequipa)], and grass-shrublands and Puya plant communities [Baccharido tricuneatae-Puyetum raimondii (subhumid orotropical plant communities with Puya raimondii), Diplostephio tovari-Festucetum orthophyllae (dry- subhumid orotropical grass-shrublands of the interandean valleys). Moreover, 4 alliances and three orders are described [Grindelion glutinosae and Citharexylo flexuosi-Crotonetalia alnifolii (shrublands and forests of the coastal hills of Southern Perú), Ludwigio octovalvis-Paspalion vaginati and Schoenoplectetalia olneyi- americani (grasslands and rushes of the Pacific Desert), Plucheion absinthioidis (coastal shrublands of the Arequipeño sector), and Sarcocornio neei-Distichlion spicatae and Sarcocornietalia neei (salt vegetation of the Peruvian and Chilean pacific coast)], and 1 phytosociological class [Carico candicantis-Caesalpinietea spinosae (dry-semiarid thermo-mesotropical shrublands and forests of the neotropical Pacific Desert and occidental Andean slops].Also, a commented syntaxonomical scheme with the phytosociological units for the Southern Peru vegetation is presented.Key words. Vegetation, syntaxonomy, Southern Peru.
Español. El departamento de Cajamarca, en el Norte del Perú, se caracteriza en general por un clima más húmedo que el resto del territorio andino peruano occidental. Teniendo en cuenta el paralelismo entre el clima y las unidades de vegetación que ofrecen los pisos bioclimáticos, los ombrotipos, la geología y los suelos, y levantando inventarios según la metodología de Braun-Blanquet, estudiamos la vegetación de este territorio. Se describen 2 comunidades vegetales, 8 asociaciones, 3 subasociaciones, 3 alianzas, 1 orden y 1 clase fitosociológica. Como resultado, se analizan la comunidad de Cecropia montana y Heliocarpus americanus (termotropical subhúmedo-húmeda) y de Muntingia calabura y Hura crepitans (infratropical seco-subhúmeda), ambas de la clase Nectandro laevis-Licarietea canellae presente en el norte del territorio. Hacia el sur, los bosques lauroides y esclerófilos están representados por las nuevas asociaciones Axinaeo nitidae-Podocarpetum oleifolii (bosques mesotropicales, húmedo-hiperhúmedos), Verbesino auriculigerae-Siparunetum muricatae (bosques mesotropicales húmedo-hiperhúmedos de áreas alteradas), Berberido beauverdianae-Myrcianthetum myrsinoidis (bosques del piso mesotropical inferior seco-subhúmedo) y Aristeguietio discoloris-Kageneckietum lanceolatae (bosques del piso mesotropical superior seco-subhúmedo), todas agrupadas en la nueva alianza Monnino pilosae-Myrcianthion myrsinoidis (Pruno rigidae-Oreopanacetea floribundi). Las asociaciones nuevas Baccharito latifoliae-Monactinetum flaverioidis (supra-mesotropical subhúmedo-seca) y Monactino flaverioidis-Colignonietum parviflorae (mesotropical húmeda) son las arbustedas sucesionales de los bosques y se agrupan en la alianza Otholobio munyensis-Rubion robusti all. nova y en la nueva clase andina Clematido peruvianae-Baccharitetea latifoliae. Se describen dos nuevas asociaciones de los pajonales del páramo (“jalca”) con sus subasociaciones: Calamagrostio tarmensis-Hypericetum laricifolii (pajonales supratropicales húmedos del sector Chota-Contumazá), con la subasociación cortaderietosum nitidae en áreas rocosas, y Agrostio tolucensis-Paspaletum bonplandiani (pajonales orotropicales húmedos-hiperhúmedos del sector Chota-Contumazá), con la subasociación puyetosum fastuosae en suelos húmedos, y calamagrostietosum curvulae como una subasociación de transición hacia los pajonales de la puna del centro del Perú. Además, hemos reconocido y lectotipificado la asociación supratropical húmeda Oreobolo goeppingieri-Hypericetum laricifolii, característica del sector biogeográfico Loja-Cutervo. Todas estas asociaciones de pastizales pertenecen a la nueva alianza Agrostio tolucensis-Paspalion bonplandiani y al nuevo orden Agrostio tolucensis-Paspaletalia bonplandiani (Calamagrostietea vicunarum). Por otra parte, presentamos un esquema sintaxonómico con todas las clases fitosociológicas estudiadas por el momento en el departamento de Cajamarca, incluyendo bosques secos y vegetación con cactus y otras plantas suculentas (Acacio macracanthae-Prosopidetea pallidae), alisedas (Alnetea acuminatae), bosques altoandinos (Polylepidetea tarapacano-besseri), y vegetación helofítica de riveras (Tessario integrifoliae-Baccharitetea salicifoliae). Como resultado de este estudio fitosociológico comentamos la biogeografía del N del Perú estableciendo los sectores Loja-Cutervo y Chota-Contumazá, y finalmente hemos cartografiado la vegetación potencial de Cajamarca English. The Department of Cajamarca, in Northern Peru, is generally characterized by a more general humid climate that in the rest of the occidental Andean Peruvian territory. Taking account of the parallelism between climate and vegetation units offered by bioclimatic belts and ombrotypes, geology and soils, and making plots according to the Braun-Blanquet methodology, the vegetation of the territory was studied. Two plant communities, 8 associations, 3 subassociations, 3 alliances, 1 order and 1 phytosociological class are described. As a result, we have analyzed the Cecropia montana and Heliocarpus americanus (thermotropical subhumid-humid) and the Muntingia calabura and Hura crepitans (infratropical dry-subhumid) plant communities, both belonging to the Nectandro laevis-Licarietea canellae class in the North of the territory. To the South, laurel like and sclerophyllous forests are represented by the new associations Axinaeo nitidae-Podocarpetum oleifolii (mesotropical, humid-hyperhumid forests), Verbesino auriculigerae-Siparunetum muricatae (mesotropical humid-hyperhumid forests on disturbed areas), Berberido beauverdianae-Myrcianthetum myrsinoidis (lower mesotropical dry-subhumid forests), and Aristeguietio discoloris-Kageneckietum lanceolatae (upper mesotropical dry-subhumid forests), all grouped into the new alliance Monnino pilosae-Myrcianthion myrsinoidis (Pruno rigidae-Oreopanacetea floribundi). The supra-mesotropical, subhumid-dry Baccharito latifoliae-Monactinetum flaverioidis and the mesotropical humid Monactino flaverioidis-Colignonietum parviflorae new associations are the successional shrublands of the forests, grouped into the new alliance Otholobio munyensis-Rubion robusti and into the new Andean class Clematido peruvianae-Baccharitetea latifoliae. Two new associations for the paramo (“jalca”) grasslands have been described with their subassociations: Calamagrostio tarmensis-Hypericetum laricifolii (supratropical humid grasslands from the Chota-Contumazá biogeographical sector), with cortaderietosum nitidae subassociation on rocky areas, and Agrostio tolucensis-Paspaletum bonplandiani (orotropical humid-hyperhumid grasslands from the Chota-Contumazá biogeographical sector), with puyetosum fastuosae subassociation on humid soils, and calamagrostietosum curvulae as transitional subassociation to the puna grasslands in Central Peru. Furthermore, we have recognized and lectotypified the supratropical humid association Oreobolo goeppingieri-Hypericetum laricifolii from the Loja-Cutervo biogeographical sector. These grassland associations belong to the new alliance Agrostio tolucensis-Paspalion bonplandiani and to the new order Agrostio tolucensis-Paspaletalia bonplandiani (Calamagrostietea vicunarum class). Besides, we present a syntaxonomical scheme with all the phytosociological class studied for the moment in the Department of Cajamarca, including dry forest and succulent vegetation with cactus (Acacio macracanthae-Prosopidetea pallidae), Andean alder forests (Alnetea acuminatae), high Andean forests (Polylepidetea tarapacano-besseri), and helophytic river vegetation (Tessario integrifoliae-Baccharitetea salicifoliae). As a result of the study of the phytosociological units of Cajamarca, we comment the biogeography of Northern Peru establishing the Loja-Cutervo and Chota-Contumazá sectors, and finally, we have maped the potential vegetation of Cajamarca.