Strolling along the waterways A real journey to the origins of life, discovering the wetlands of the New Caledonian Great South
The sites 28 Preambule 04 Reading the landscape 06 Preface Contents Yaté Lake, a central point 42 Yaté Lake and surrounding areas The Yaté River The Lakes Plain 46 A very specific context 48 The Madeleine River, Netcha, The Southern Woods 50 The Great Lake – The Lake in Eight The Lakes 56 The Lake in Y – The Long Lake The Jade Lake - The Xere Wapo Lake The Road Pass Lake Other sites 63 The Wash House The Capture - The Spillway - The Cobalt diggers Hole The Japanese Bridge - The Toboggan Trail Pernod Creek - Camille Waterfall Wadiana Waterfall – Prony Blue River Provincial Park 30 The Blue River The White River The Month of May River At the confluence Wetlands 04 What is a wetland? The international Ramsar label Values, functions, roles and issues Shaped by time 08 The geological base Water, founder of landscapes Shaped by humans 14 Logging Mining Water exploitation Typical landscapes 17 Typologies of wetlands Unique flora in the world Discreet fauna The natural heritage and thewetland landscapes of NewCaledonia’s lakes located in theGreat South aremanaged through a vast network of protected areas, enhanced by their classification under the International Convention on Wetlands known as Ramsar. These landscapes and biodiversity deserve to be preserved for future generations. This is also the vision given to the Tropical Wetlands Relay Centre, a national initiative led fromGuadeloupe Island by the French Committee of the IUCN (International Union for Conservation of Nature): “wetland areas preserved for future generations in French tropical territories”. The South province, through its process of labelling the most important wetlands in its territory, contributes to this vision through the implementation of facilities intended to make them accessible to visitors, thus raising public awareness of their socio-ecological importance and the need to preserve them. Because knowing them better also means respecting them more. This is the invitation that the South Province wished to extend to all readers of this guide, whether they are local residents, decision-makers, business managers or simply people curious about these environment in New Caledonia or elsewhere. The Tropical Wetlands Relay Centre is pleased to join this invitation, which offers you the opportunity to combine the pleasure of walking with that of discovering this exceptionally rich environment of New Caledonia’s South province, along the waters, over time. The IUCN Tropical Wetlands Relay Centre - International Union for the Conservation of Nature. Niaouli trees in the Blue River Provincial Park 3 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways
44,000 ha 5 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways Water that sleeps but works 4 Strolling along the waterways What is a wetland? Functions, values, roles and issues of wetlands Wetlands Preamble _ A vital issue for populations The Great South Lakes region constitutes a major freshwater resource for New Caledonia, a unique biodiversity and landscape and a cultural heritage. Wetlands also reduce the natural risks linked to flooding and provide islands of freshness. Biological functions They promote the diversification of habitats for both flora and fauna (feeding, refuge and reproduction areas). The fluctuation of water becomes the guarantee of a remarkable, sometimes unique presence whose existence depends on these environments. Social functions As “socio-cultural showcases”, they can reinforce the identity and attractiveness of territories: improvement of landscapes and the living environment, provision of cultural testimonies or past activities, creation of leisure areas (swimming, hiking, mountain biking, canoeing), hunting and fishing areas, develop traditional pharmacopoeia, places for nature education where the general public can come and observe specific biodiversity. Hydraulic functions They behave like natural sponges, capable of storing and then releasing water, thus playing a role as a natural regulator (low flow support*). During rainy periods, they: • store and regulate the volumes of water and flows, • attenuate and spread out flood peaks, • limit runoff, • protect soils against erosion. In the dry season, they: • promote water infiltration, • replenish waterways and groundwater, • ensure a certain volume of water during periods of drought. Purifying functions They improve water quality by taking part in the retention and filtration of numerous substances and thus allow their natural purification. Climate functions They act as “natural thermoregulators” contributing to climate regulation, in particular by capturing large quantities of carbon, even more than forests. “Wetlands are areas ofmarshes, fens, peat bogs or natural or artificial water, permanent or temporary, where thewater is stagnant or running, fresh, brackishor salty, including areas ofmarinewaterwhosedepth at lowtide does not exceed sixmeters.” Definition of the 1971 Ramsar Convention Blue River Provincial Park Yaté Lake The Lakes Plain Ramsar, an international Label The Great South Lakes, a site of international importance A preliminary study by the National Museum of Natural History, led in 1998 on the entire territory, identified the region of the Great South Lakes as the largest wet area of New Caledonia and the most original in terms of its ecological richness, with 90% endemic plant formations. Like the lagoon, listed as a World Heritage Site, this terrestrial area is an exceptional and unique natural heritage in the world, recognized internationally by its classification under the Ramsar convention in the same way as famous wetland areas such as St Michael’s Mount Bay, Lake Titicaca and the Moorea or the Venice lagoons. Ramsar Registration date: February 2, 2014 GPS coordinates: 22°09’S 166°46’E Surface area of the Great South Lakes classified site: 43,970 ha These wetlands often unfairly suffer from a bad image, with unhealthy conditions or mosquito nests. However, these environments, where water is the dominant factor of life, constitute genuine reservoirs of biodiversity: they are a fabulous asylum, a Noah’s ark for flora and fauna but also for us, humans. Protect water, a source of life The Great South Lakes region represents the largest freshwater reservoir in New Caledonia. Connected to a vast network of creeks and groundwater, the region’s various wetlands (lakes, marshes, rainforests) help regulate the flow of waterways, thus protecting against flooding, drought and erosion. Fires, mining activities and logging are factors that disrupt this water resource and biodiversity. The classification of the site under the Ramsar convention gives the Southern province a responsibility in preventing these various threats. It also implies that the developments and activities taking place there are part of a sustainable development approach consisting of limiting and better controlling pressures on this territory. 1 1 1 1 Recreation & education A natural filter Sponge Biodiversity reservoir * Low water level: Periodic drop in water levels (of a river); the lowest water level.
7 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 6 Strolling along the waterways Water, its blue gold Numerous shades Landscapes changing over time, throughout the walk. Did you say blue? River, creek, lake, waterfall, marsh... Transparent, milky, dark... Blue, green, white, grey... The Great South Lakes Site: (re)discover its unique landscapes A remarkable colour palette Red earth loaded with iron... …scattered with vibrant colours Its flora: shades of green to grey... Reading the landscape Oasis Falls Broken mining armour* Gushing waterfall Water as a conductor A contrasting landscape resulting from a hydrogeological marriage On the path, revealing itself between sparse Gymnostoma, the emergence of a plateau glowing red or black with metallic shine; an armour of cemented ferrous elements forming an indurated crust: the carapace of the mining grounds contrasting with the tender green of the flora. Here, the course of the Carénage (Fairing) River abruptly interrupts: this difference in altitude gives a glimpse of the work of water, which alters the rock over time to reshape new micro-landscapes like this waterfall, a haven of well-being. Place called the Oasis GR®NC1, stage 1 of Prony > Neocallitropsis refuge. Here, a witness to erosion: the shaping of the water created a collapse of the plateau and gave rise to this waterfall. * Armour: shell of mining terrain whose thickness varies from 1 to 3 m “The landscape is the expression observable by the senses on the surface of the Earth of the combination between nature, techniques and human culture. It is essentially changing and can only be understood in its dynamics, that is to say within the framework of History which restores its fourth dimension.” Jean Robert Pitte What is the landscape?
9 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways Water circulation 8 Strolling along the waterways Water, the founder of landscapes Shaped by time Shaped by water The geological base Shot and armour result from the accumulation of iron at the top of the profile. Iron, poorly soluble, is not leached by water and accumulates in the first centimetres of the profile. - Permeability - Rapid infiltration - Temporary flow buffer stratum with formation of surface layers in the event of rain - Weathered rock facilitates water circulation - High storage capacity which regulates flows and limits flooding - Supply of slope sources and deep drainage of massifs - Conductive layer - High porosity - Low permeability - Capacitive layer Horizon composed of gravel, coming from the dismantling of the armour. From rock to ground, where does this typical colour come from? The red colour of soils in the Great South is due to the presence of oxidized iron: rust, in a way. In our humid tropical climate (with high temperature and heavy rain), the parent rock (peridotite) weathers and leads to the formation of these so-called lateritic or iron soils topped with a crust. Also called red earth, poor in nutrients (naturally deficient in nitrogen, phosphorus, potassium, calcium), but rich in heavy metals (nickel, chromium and cobalt) potentially toxic for plants, these soils are at the origin of a drastic environmental selection which results in a high rate of endemism. The flora and habitats that develop there, resulting from a long evolution, constitute some of the most original ecosystems on the planet, including very rare, even threatened, species. Laterites are the products of more advanced alteration. We distinguish the yellow ones, exploited by the mining industry, and the red ones. They are the first phase of alteration. They retain the structure of the parent rock but are very friable. The mining industry exploits them, this level is even richer in nickel than laterite. Rocks from the earth’s mantle, called ultrabasic (green-blue in colour, rich in iron, magnesium, nickel, cobalt, chromium and manganese and poor in silica). Schematic profile showing the succession of horizons or alteration products of Peridodites (Illustration based on the Jeanpert diagrams, 2017) Schematic profile showing the principles of hydrogeological functioning The armour Aquitard semi-permeable The gravel Upper aquifer superficial 3 m 15 m 25 m 30 m 40 m The laterites Red ones Laterites Fractured saprolites & peridotites Armour Deep aquifer fractured to karstified Yellow ones The saprolites The peridotites The peridotites Essentially made up of a green mineral -olivine-, the colour of peridodites is not always easily perceptible for two main reasons: • The green of peridotites is extremely dark, almost black. • When this rock weathers, it takes on a patina and the colour of this patina is orange. The presence of these mantle rocks on the surface testifies to a geological phenomenon called obduction*. While they are rarely observed in the rest of the world, they cover more than a third of the surface of New Caledonia’s Main Island (Avias, 1967). The landscapes of the Great South offer striking contrasts created by geological history which directly influence soil characteristics and local biodiversity. Sculpting the reliefs, forming the geological profile of the subsoil, constraining movement and human settlement, water reveals itself to be a natural constituent of the great South’s landscape. A surface hydrographic network Seen from the sky, the Great South presents a dense hydrographic network, scattered with multiple bodies of water, lakes and marshes, a genuine mosaic of silvery or blue-green spots where some waterways seem to slip through, get lost, dilute and resurface. These disappearances in fact reveal a very complex hydrogeological functioning invisible on the surface. A unique example on a global scale The alteration of peridotites has led to the development of real karst* type models where water infiltrates mainly into the subsoil, instead of flowing on the surface, thus digging numerous underground paths or cavities. The Great Lakes region is therefore based on an original underground system comparable to that which models the limestone regions but here, the limestone is replaced by peridotite, which does not completely dissolve, and its coat of lateritic alteration. It is called “peridotitic pseudokarst”. Karst landscapes are characterized by the existence of: • sources and resurgences, • losses or dry valleys (openings through which a watercourse becomes underground after a course in the open air), • sinkholes, which can be defined as “more or less circular closed depressions that can be a few meters to more than a kilometre in diameter and a few meters to several hundred meters deep” 1. A fragile system that is still poorly understood Sinkholes appear to connect surface water and groundwater systems. This phenomenon therefore makes the aquifer particularly vulnerable topollution. Theundergroundcirculation of water can be rapid, and its poorly identified path without corresponding to the surface watersheds, further increases the fragility of this system. * Karst system: region of limestone formation characterized by the preponderance of underground drainage and by the development of an original topography due to the dissolution of the rock under the action of water (caves, chasms, resurgences, etc.) 1 Diagnosis of sinkholes in New Caledonia by the CNRT, 2018 * Obduction: geol. Overlapping of an oceanic plate over a continental plate.
11 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways Hydrographic network Ramsar area Lakes Fluctuations of Yaté Lake 10 Strolling along the waterways A winding shore Explored with family Surprising maquis (shrubland vegetation) A riverside landscape As rivers and creeks are subject to currents, and their banks to periods of submersion, the banks present specific plants, with tortuous shapes that are firmly anchored but with the flexibility of steel. Sometimes deep, sometimes distended, these rivers create varied landscapes and offer multiple recreational spaces. The Great South, an abundant water reserve for theMain Island TheGreat South Lakes region is theonly one inNewCaledoniawhere the hydrographic network is meandering and where numerous bodies of water accompany the rivers. The pseudokarst base makes it possible to regulate the flow rates of the various rivers in the region: support of flow rates in the dry period by water from the deep water table and buffering of floods in the wet season, via the infiltration of water into the base and the role capacity of the lakes. Aquatic ecosystems _ The lotic environment Suitable for running water (rapid circulation of water), it corresponds to all waterways: rivers, rivers, creeks, etc. Mapping of lotic and lentic environments N YATÉ LAKE Blue River White River The Month of May River Pernod Creek The Lakes River Yaté River Carénage (Fairing) River Lake in 8 Kauri Trees River The Great Lake Kwé Binyi River 0 5km 1 The Lakes River
13 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 12 Strolling along the waterways Water sinkhole Enigma behind the scenes Soft sponges Intermittent Dotted with bathtubs, the Lakes Plain Crystal clear water contrasting with the metallic crust of the glowing soil or a bowl of murky water teeming with wet grass, the sinkholes hidden within the vegetation offer us their magical atmospheres to contemplate. The large ones are subject to sedimentation while those with steeper walls are the superficial manifestations of erosion phenomena which take place in the subsoil, under the action of “pseudokarstic” underground flows. Mysteries to be solved An alignment was noted between several depressions because a large fracturing - fault allowed their formation. The presence of a withdrawal phenomenon (extraction from below caused by the circulation of groundwater) constitutes one of the origins of these depressions. _ The lentic environment: lakes and sinkholes Suitable for calm waters, with low flow, or even stagnant waters, it corresponds to lakes characterized by their large extent, to ponds, etc. Illustrations based on the Serino diagrams, 2012 Collapse sinkhole Funnel or bowl sinkhole Flat bottom sinkhole Drawing Following the sudden collapse of the armour. In V. In a flat-bottomed bowl linked to the accumulation of sediment. Shape Circular and small. Circular to oval, deep and modest in size. Circular to oval, shallow, larger in diameter. Edges Steep walls with large blocks of collapsed armour at the bottom. Gentler sloped walls with large blocks of collapsed armour and gravel in the slopes. Soft walls. Water Transparent, if present. Transparent, if present, very variable in height, seeming temporary. Blurred, if present, at fairly constant and probably permanent height with herbaceous and hydromorphic vegetation and often shrubby to treelike vegetation on the slopes. *? *? © Bio Eko Types of sinkholes There are several types of sinkholes. The diagrams opposite illustrate the 3 main cases encountered in the South. An example of a funnel sinkhole, the Tahitian Hole, at the Lakes Plain, forms a vast cross-shaped depression, approximately 25 m deep. Today, it represents a unique case. The water staying there temporarily presents rapid piezometric variations and the sinkhole reveals a loss when it finds itself dry. Types of sinkholes Lake in Eight
15 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways Ramsar area The human footprint Yaté Dam Lakes and sinkholes Forest plantations Mine-related infrastructure Main roads and tracks Tracks Habitat 14 Strolling along the waterways Forest exploitation The mining industry Shaped by humans Mine landscapes in literature 1 Among several writers predominates the image of a metamorphosis of landscapes used for economic reasons, ravaged by prospects describing the mountain as a wounded creature, a sad landscape or one with chromatic uniformity. “Huge portions of the island are gigantic mineral blocks” J. Mariotti. “From the front, the extreme tip of the cape outlined its reddish and bare mass with its sides open with bloody wounds in the grey heather - the prospects of the nickel seekers -.” J. Mariotti. “They seemed, these majestic chains, to say with pride to those smaller than them: Stand back! Make way for us! We are the serpentines, New Caledonia’s backbone. We are the ones who make the law, we give the movement, we create the activity. In our bosom we contain the infernal lava of Pluto, crystallized into inexhaustible riches. See these yellow, gaping wounds, which open in stages in our large chests; they are dug there to extract the nickel which is our flesh. And these deep, bloody bowels, which yawn in our red clay dermis; they were incised to tear out our chromium ribs which will, throughout the world, harden metals. Look at these black holes which penetrate into our bowels, like the lairs of cyclops; they are dark and tortuous tunnels which lead into places full of mysteries, bleeding our veins blued with cobalt.” Savages and civilized, G. Baudoux “The landscape is sad, with the grey tones of its shrubs which resemble thyme laurels and the reddish colour of the soil. There is a melancholy there common to all places where there is a lack of water and large trees.” Mining, F. Ordinaire. “An impalpable dust of yellowish ochre covered the entire landscape like a veil of earthy saffron (...)” Holes and galleries are scattered in this island, giant terraces cut deeply into the mountain, winding roads scar its sides, erosion exposes the rock, large greyish spots reveal the path of bushfires, crisscrossed by numerous tracks imposing an artificial mesh signed by the hand of man. Mining activity leaves its mark on the territory. Mining in the Blue River Provincial Park (BRPP) The mining past of the areas that today make up the Blue River Provincial Park and its surroundings mainly concerns the Month of May River, Bon Secours and Renaissance mines. They were exploited using open-air quarrying techniques. Forestry production, high plots in the plain In the mid-1970s, forestry essentially based on Caribbean pine developed. The sector then diversified with endemic tropical species (Araucaria, Kauri tree, Sandalwood, etc.) An arboretum as an emblematic tree Located in the Blue River Provincial Park (BRPP), this arboretum is home to 14 (including 11 endemics) of the 20 species of Araucarias listed in the world. To date, it constitutes the largest global collection of its kind with nearly 20 different conifer specimens. It pursues three missions: conservation, seed orchard and public awareness support. Traces from the past Traveling through the Great South, we notice the presence of old, discreet vestiges, gradually disappearing into the vegetation: rails, schlittage (sleigh) paths*, a winch locomotive (towards the White River) but also some well-preserved witnesses of this history such as the Perignon Bridge, entirely made of wood in 1958. In New Caledonia’s Great South region, there is a feeling of nature. Infrastructure and roads are few. The majority of the habitat is distributed among four tribes - Goro, Touaourou, Wao, Unia - installed on a narrow plain along the coast. The low population density is explained by the reduced size of the cultivable space and the absence of colonial pressure. A brief history “In 1866, Governor Guillain entrusted Captain Sebert with responsibility for supplying the emerging capital with wood. The Southern Forests were chosen. He found exploitable forests in Prony, located near the sea. The operations began in 1868, in the Kauri Bay area. In 1873, the artillery gave way to the prison administration. From 1889, the condemned were replaced by the relegated. The workforce swelled. The yield dropped. The men were scattered between Bonne-Anse, Port-Boisé, The Carénage, North Bay and Prony. This forestry adventure ended up in 1907 and operations closed in 1911.” Guide GR®NC1, From Prony to Dumbea, Jean-Francis Clair Opposite: Overview of the former forestry establishment of Prony >>> Then, at the beginning of the 20th century, the exploitation of the forests of the Blue River and the White River valleys began. Thirty-seven kilometres of railway tracks were laid to transport locomotives to the operating area and then to transport the logs to the sawmill settled at the mouth of the Pirogues River. During the SecondWorldWar, this railway line was also used by the Nickel Company to evacuate the Chromium ore which it had taken over. In short, •Cobalt: low content. At the end of the 19th century and at the beginning of the 20th century, New Caledonia was the main supplier of this precious metal. Digging narrow trenches was the only means of prospecting to cross the thick lateritic cover in order to reach the minerals. When the cobalt diggers followed interesting concentrations, they opened galleries called cobalt diggers’ holes. •Chromium: low content. A deposit discovered around 1890. Located in coastal or weathering formations (examples: Prony and Ouen Island). •Iron: the armour contains a lot of it. Operated at Goro in the years 1940 and 1941 and at Prony between 1956 and 1968. •Nickel: considerable reserves, but the low content has delayed its exploitation for a long time. (P) Mining prospecting wells (a technique widely used until the 1970s in the search for this ore), made by hand using crowbars and shovels, could reach a depth of 20 m. Several mining companies exploit it. GR®NC1 Guide, From Prony to Dumbéa, Jean-Francis Clair, extracts 1 .Eddy Banaré ANC. AlbumNouméa-Aden-Mascara 101 Fi –68 Funicular, Carenage Bay ©B. Suprin * Schlitte : Long sled used to transport cut wood on rails © Nicolas Charpin A mine in Prony P
17 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways The Ramsar area perimeter Hydrographic network Swamp Hydromorphic plains shrub Temporary hydromorphic soil shrub Maquis mosaic of areas with temporary or permanent hydromorphism Maquis mosaic in Gymnostoma & hydromorphic areas Wetlands with Niaouli trees. 16 Strolling along the waterways The hydroelectric dam Built between 1956 and 1959, the 60 m high Yaté dam is made up of three impressive slide spillways and flood spillways. This monumental work, however, remains barely perceptible fromthe road. Its construction led to the creation of a hugewater reservoir which flooded around 4,000 ha of land. An artificial central receptacle of themouths of several rivers, Yaté Lake connects thenorth-westernparts,with the confluenceof the natural beds of the Blue and White Rivers and the south-eastern parts of the Ramsar area, with the Lakes River and Pernod Creek. A 2.6 km long gallery leads thewater to the factory located below. It supplies the urban area and the Doniambo factory. The exploitation of water as a source of energy Typical landscapes Typology of wetlands The main typologies of wetlands are distinguished according to the degree of hydromorphic * of the soil. The map below shows the location and distribution of these major typologies. * saturation of soil pores with water over a more or less long period of the year leading to asphyxiation phenomena which disrupt soil fauna and vegetation. A few figures: Dam inaugurated in 1959, length: 641 m Lake surface area: 40 km2, dimensions: 22 km by 6.5 km 10% of the Ramsar classified area Watershed supplying the reservoir: 436 km2 The dam meets 30% of the electricity needs of public distribution in NC. N 0 5km 1 YATÉ LAKE Blue River White River The Mont of May River Pernod Creek The Lakes River Lake in 8 Great Lakes Yaté Lake at the Pérignon Bridge, in 2007- © J.M. Mériot Yaté Lake - © Catherine Geoffray Press article, 1990 © Hourdan In 2017 Shaped by humans
19 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 18 Strolling along the waterways Particularities linked to the degree of hydromorphism of the soil The maquis of the almost permanent wetlands occupy the low plains and the alluvium of the waterways which drain it. They are divided into three large formations: - The maquis of the hydromorphic plains - The riparian maquis, along rivers and creeks - The plant grouping of sinkholes. An uncovered landscape with distant horizons These large expanses of grass, undulating in the wind, offer a landscape that is often very open where the gaze sweeps across and embraces the horizon. A few slender shapes of shrubs emerge very occasionally from this herbaceous mass where droplets and cobwebs hang. Surrounded by the surrounding reliefs or by areas of high shrub installed on low reliefs, the masses of compact plant tufts in areas of variable density alternate with the sparkling zones reflecting the sky. The maquis with almost permanent hydromorphism The maquis of hydromorphic plains A unique ecosystem under threat The maquis of almost permanent wetlands (maquis of hydromorphic plains and riparian maquis) constitute a particular and very original ecosystem, which is only found in the extreme south of New Caledonia’s Main Island. Theymay find themselves threatened by fires, futuremining, forest and industrial activities since they are directly under the influence of variations in the hydrological environment likely to be modified by water reservoirs and mining works. Formerly a tree-like landscape These wet and floodable areas would have previously been occupied by shrubby, tall to tree-like marshy formations according to palynological studies carried out in the lakes of the Goro plateau (Hope and Pask 1998) - lakes constituting real archives of the history of the vegetation of the South of the Main Island over the last 30,000 years. Today, this grouping is referred to as the association with Pancheria communis and Cloezia buxifolia (Jaffré, 1980), shrubs commonly found in these environments
21 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 20 Strolling along the waterways The shrubby swamps Isolated or in narrow cord, sculpted by water The shrubby swamps stretch discontinuously along the more or less stony banks of the waterways. Composed of shrub and herbaceous species supporting waterlogging and temporary, partial or total coverage by water, this maquis is very rich in specific species despite its limited surface area and is difficult to assess. Equipped with highly developed root systems, they resist being carried away during cyclonic floods and often lean downstream. The plant grouping of sinkholes A concave setting, an oasis of serenity This plant group is mainly composed of Melaleuca quinquenervia (niaouli tree) and Sannantha leratii (false heather), often located on the edges of banks or all around the immediate perimeter of a sinkhole, up to the high water level because it adapts to temporary submersions, as well as more clearly aquatic species, such as Lepironia articulata, Eriocaulon spp (opposite) appearing as ephemeral and specific white pompoms emerging or not from the surface of the water. A very original biotope under threat The vegetation of the riparian shrub andmarshy areas has been largely degraded due to fires. The fact that these populations of rare species are already fragmented and reduced increases the risk of extinction of the species or at least the loss of its genetic integrity. This very original biotope deserves to be communicated and monitored for better preservation. Several species are listed as endangered, threatened, vulnerable, etc. such as Retrophyllum minor or Dacrydium guillauminii.
23 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 22 Strolling along the waterways Temporary hydromorphic maquis Wetlands with niaouli trees A tree of light loving open environments Emerging from the water or punctuating the banks of lakes and rivers with its singular shape, the niaouli tree likes to capture the light through its white trunk covered with its multi-layered onion skin bark. In 1893, Jules Prévet filed a patent and marketed his essential oil under the brand Goménol, the name of which partly refers to an estate called Gomen in New Caledonia. A tree full of resources and linked to tradition The essence extracted from the leaves, rich in eucalyptol, is used against bronchitis. Its bark is used to cover the walls and roofs of the native huts. It holds an important place in customary ceremonies: during a birth, the infant is wrapped in niaouli tree bark to protect him and give him strength. During a funeral, the leaves and branches wrap the white currency authorizing the exchange between two clans. Moving away from the flow, a landscape at eye level Away from the water circulation zone, different facies develop. A discontinuous herbaceous stratum present on alluvial soil reveals areas of gravelly or armoured soil. It is accompanied by a loose shrub layer barely exceeding 1.50 m, sometimes topped with trees reaching a few meters in height, establishing themselves on the high or stony parts. This floral procession includes around 185 species with an incredible endemism rate of around 94%. A transitional plant association This ligno-herbaceous maquis, which can be described as semihumid, is found between the foothills of the lower slopes and the maquis on soils with almost permanent hydromorphism. It benefits from a supply of water and organic matter coming from the slopes. Composed of specialized species capable of withstanding phases of soil waterlogging, this plant group, existing only in the extreme south of the Main Island, was defined by the publication of Jaffré, in 1980, as an association with Homalium kanaliense and Costularia comosa today called Tetraria comosa.
25 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 24 Strolling along the waterways Dacrydium araucarioides Agathis ovata Mountain Kauri Drosera neocaledonica Cladonia pycnoclada and Cladia retipora Arbusculate Lichen and Coral Lichen Dacrydium guillauminii Cat Tail Callitris pancheri Former name: Neocallitropsis pancheri Conifers > The originals A unique flora in the world Without stem, leaf or root, slow growing, lichens result from the symbiotic association between a fungus and an algae. Growingwith its feet in thewater, this small shrub is characterized by its needle-shaped leaves, very bushy on the branches, which give it the appearance of a cat’s tail. One of the rarest conifers in the world. The leaves, structured in tight scales, aggregate into smooth and sinuous branches, in the upper half of the trunk, giving this small tree a candelabra shape. Recognizable by its rosette of red leaves covered with hairs, the carnivorous Drosera produces a false nectar which attracts insects. Those who stick to it are killed! Its characteristic shape with a tabular crown, in the shape of an isosceles triangle, points downwards emerges from dense humid forests of medium altitude or from the shrub as isolated individuals. P P Banks of the Lakes River Madeleine Falls, Lakes Plain This small tree with a very twisted trunk, giving it the appearance of a giant bonsai, was widely exploited for its oil, used as a perfume fixative. As a threatened species, it became, in 1942, the first one to be officially protected locally. Callitris pancheri The name of this tree is one of around thirty groups of species dedicated to the botanist Jean Pancher (1814-1877) who lived in NewCaledonia from1857 to 1877 andwho died in Uaraï Bay near Fort Teremba (Moindou, New Caledonia). An exceptional endemism The isolation of New Caledonia for millions of years has allowed theparticular evolutionofmany species. In theGreat South, extreme living conditions, with lots of sunshine, soils unfavourable for plant growth, generate an exceptional rate of endemism. The Ramsar labelled area offers a multiplicity of natural habitats, with mining shrubland, humid forests, lakes and swamps. © Jean-Jacques Villegente- Netcha © Dominique Garnier- Madeleine waterfall © Katia Michalezyk © Katia Michalezyk © Katia Michalezyk- Plaine des Lacs © Katia Michalezyk- Plaine des Lacs Eriocaulon neocaledonicum Blechnum francii Franc’s aquatic fern Pandanus lacuum Water Pandanus Utricularia Uliginosa Endemic Protected Xyris neocaledonica Aquatic species Retrophyllum minus Corkwood tree This aquatic fern, attached to the bottom of the water by roots, can grow to incredible depths of 10 m. Grass located in the marshes of the mining areas of the Great South where three species are present, all endemic. The solitary flowers develop three bright yellow petals. This herbaceous carnivore, with a long floral stem punctuated with purple flowers, ingests microorganisms thanks to its fine foliage equipped with utricles, like somany wineskins with trap doors which trap their prey by sucking them in as soon as it comes into contact. Recognizable by its slender stem supported by aerial stilt roots submerged in water, this rare, microendemic pandanus is in great danger. This semi-aquatic herbaceous plant sometimes lines the edges of rivers and lakes. Its flowering takes place in dry periods when the plant is then more exposed. P P P Bed of the Lakes River The Lakes Plain The Lakes Plain Retrophyllum minus Formerly used by miners for making corks, it owes its name to the lightness of its wood, comparable to that of balsa. It is a relic conifer of Gondwanan origin, with a very particular habit, a characteristic “bottle” trunk, resembling a baobab. This species formerly occupied the vast marshy areas of the Lakes Plain, thus constituting real marshy forests today replaced by ligno-herbaceous shrub of the marshy areas. (Palynological studies in the lakes of the Goro Plateau (Hope and Pask, 1998). Very sensitive to fire, trampling and mutilations of campers, it particularly attracts the attention of international bodies for nature conservation. Often represented by a few isolated tree plants present along waterways, it can resist total submersion for several days. © Nicolas Charpin © Katia Michalezyk- Madeleine River © Irène Létocart- Lakes Plain © Katia Michalezyk- Lakes Plain © Adeline Suprin © Katia Michalezyk- Plaine des Lacs Light and anchored Gondwana Relic Crescent feet in the water Rare Rare, in critical danger E E E E E P P P P E E E E E E P P P P R R R+ R+ R R R R
27 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 26 Strolling along the waterways Fishes Birds A discreet fauna Protogobius attiti Egretta sacra albolineata Sacred Egret Haliastur sphenurus Eagle or Whistling Kite Giuris viator Rainbow Lochon Anguilla megastoma Mountain eel, Red eel Phalacrocorax melanoleucos melanoleucos Pied Cormorant Galaxias neocaledonicus EN DANGER ! Living in fresh or brackish water, these predators (25 to 30 cm) of rivers are found in the IndoPacific sphere. A catadromous species, it is born at sea, migrates to rivers to grow before returning to the sea again to reproduce (only once in its life) and die. An eel seen in fresh water has never reproduced. Frequenting lakes, mangroves and river mouths, this bird with its white fleece, uncommon in N.-C., lives in colonies. Recognizable by its hooked black beak and its beige belly streaked with red, this raptor hovers above wetlands. This emblematic species, a vestige of the ancient fauna of Gondwana, is microendemic to the Lakes Plain. This rare fish particularly likes fresh water and rocky bottoms. Rather carnivorous, it feeds on small crustaceans and aquatic insects. It is seriously threatened with extinction due to the introduction of other fish (Black bass, Tilapia, Rainbow fish) which feed on it, chase it from its territory or enter into food competition. P P P P Lakes River, Great Lake, Lake in Eight, BRPP Micro-endemic of the Lakes Plain Micro-endemic of the Lakes Plain Lake Xere Wapo Prey spotted Neck unfolded, beak pointed Nourishing water Looking for its dinner Unfair competition Endangered fish © Nicolas Charpin © Nicolas Charpin © Nicolas Charpin © Nicolas Charpin © Julie Villegente © Frédéric Desmoulins © Frédéric Desmoulins ! P P Observation of nests on the Drowned Forest’s trunks 20 to 30 pairs Visit Yaté Lake The little beasts Haliplus oberthuri Paratya caledonica Lynceus insularis (crustacean) Leptoceridae Oecetis Ischnura pamelae Dragonfly Soundscape, listening to biodiversity The study of these sounds makes it possible to estimate biodiversity, to detect a disturbance of the ecosystem, to establish monitoring of the restoration of disturbed systems and to establish a temporal (day/night) and spatial signature of the fauna present in these landscapes. Thus, several scientists, including recently a team from the IRD, the IAC and from Poland, noted that the forest had, in places, become silent. They highlighted a causal relationship between this silence and the presence of the electric ant. Indeed, this invasive species, introduced in 1960, devastates everything in its path. Many insects (worms, caterpillars, cockroaches, etc.) are disappearing, causing a change in soils and animal populations. The decline of these various insects, which are the kagubirds’ only pantry, leads the latter to flee and drastically reduces their living space. This small (2 cm) speckled shrimp, living strictly in fresh water, displays a multitude of colours (blue, yellow, black, red, white, etc.) From the order of Trichoptera, this larva adapted to life in fresh water makes a small sheath from sediment to form a roof. Endemic to temporary sinkholes, the female lays eggs when the sinkhole is wet, which only hatch after a period of drying. The new generation will only appear at the time of re-watering. *rediscovered in the South more than 130 years after its first collection in the AnseVata Marsh of Noumea (before 1883). Between two worlds Protection of the biotope Imaginal flight Riverside calm This rare beetle Thought gone * © Nicolas Charpin © Nicolas Charpin © Nicolas Charpin © Nicolas Charpin © Nicolas Charpin © Frédéric Desmoulins Discovered in 1998, it was named in honour of one of the Melanesian chiefs of Goro tribe, the great chief Charles Attiti, who died in 2004. Glyptophysa petiti Having become very rare since the early 1990s, this aquatic snail, reaching 5-8 mm in size, as an adult, is in danger of extinction. * “all of the biological, geophysical and anthropogenic sounds that emanate from a landscape and which vary in space and time, reflecting important ecosystem processes and human activities.” Pijanowski and Al., 2011 Endemic Protected Rare E P R E E E R R R P P P P P E E E E P
The Blue River Provincial Park P.P.R.B. TERRESTRIAL PROTECTED AREAS Yaté Lake Ma Madeleine Falls N Netcha P Pine Peak Y False Yaté River K Great Kauri Peak B Yaté dam H High Pourina River S The Southern Woods C Hidden Forest M The Springs Mountain D Cape N’Dua F Northern Forest T Thy Valley The sites Ma N P K Y S B H M T F D C Ramsar area perimeter Main hydrographic network Yaté Dam Lakes and sinkholes Marshes, hydromorphic shrub The Perignon and Germain bridges Germain Bridge Unia Plum Prony La Coulée Waho Touaourou Goro The Concession Pérignon Bridge YATÉ LAKEX THE LAKES PLAIN Lake in Y P.P.R.B. YATÉ MONT-DORE Drowned Forest Blue River White River Month of May River Netcha South Woods Madeleine Waterfall Pernod Creek Long Lake The Great Lake Lake in 8 The Path Lake «Jade» Lake Lake Xere Wapo The cobalt seekers Hole The Capture Déversoir The Laverie Wadiana Cascade Lakes River Kiki Swamp Yaté River The Oasis Prony Sources The Carénage River The Sting The Toboggan The Japanese Bridge N’Dua Cape N Camille Cascade 0 5km 1
31 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways Ramsar area Bridges: Germain (G) Perignon (P) Month of May (M) The Great Kauri Devil’s Horn Great Waterfall Blue River Provincial Park The Locomobile The Mule Drivers’ Refuge The Park House Protected area Yaté Lake Rock’s Peak Buse Peak Mont-Dore Mouirange Peak The Two Nipples 1233 780 Gué 165 643 878 776 1004 Sunshine Mine Gwé Daru Gwé Buru Poco Mié Dumbéa River Plum Bay The Pirogues Bay Ué Bay La Coulée River Pirogues River Sources Mountain Mount Koghis Mount Pouédihi The Blue River Provincial Park (BRPP) The Drowned Forest Bon secours The Blue River The White River The Month of May River G M K R K D D C C L R L P Created in 1980, in the heart of the Great South’s massif, the Park extends over 22,000 ha and includes the nature reserves of High Pourina and High Yaté. Varied atmospheres and environments It contains varied plant formations (mining shrub, dense forests and wetlands) and is home to unique species in the world. Of great variety, the forest is made up of kauri trees (Agathis lanceolata) and araucarias (Araucaria bernieri) which sit alongside endemic palm trees (Cyphophoenix fulcita) as well as spectacular tree ferns (Cyathea vieillardi). Omnipresent water, shaping landscapes The White and Blue Rivers are the two main rivers of the BRPP. Permanent, they supply the water reservoir of the artificial lake of Yaté. Along these waterways, riparian forests develop which have the advantage of not depending on rainfall and which cross all environments. Located essentially on the outskirts of these open freshwater areas, the Park’s marshes have vegetation adapted to more or less permanent waterlogging, forming a transition with the shrub on the slopes. Proud of the conservation of an emblematic bird Most New Caledonian land birds are found there. The BRPP is home to the largest population of wild kagu birds. Specimens bred in captivity, at the Noumea Provincial Zoological and Forestry Park, have been successfully reintroduced into the park. Unfit to fly and therefore subject to predators (dogs, cats, pigs, etc.), they reproduce little (a single egg per year), hence their rarity and their protected status, a program led by the South Province. Due to deforestation, caused by the exploitation of nickel mines, humans have restricted its living areas and represented a certain pressure for these endemic Rhynochetos jubatus. A multifaceted park, an example of biodiversity Why can’t the kagu fly? It would only lack powerful pectoral muscles, atrophied over time because it used to live in an environment without predators and find its food in the ground, so flight was no longer vital to it. Rainforest At the Grand Cascade The Blue River The Perignon Bridge The Blue River
Discreet traces The GR®NC1 trail follows an old track traced on the mountainside for logging, with destroyed culverts, vestiges of logging, a place called La Tranchée, a small canyon of red earth, cut into the mountain by the old logging machinery. 33 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 32 Strolling along the waterways Micro landscape Bright reflection Rear view soul-mirrors The Upper Blue River A narrow cord Humidity and lushness From the wide and peaceful outlet of the Blue River, the path, a long ribbon of red earth, gradually penetrates into the silent shadow of the forest. The river in turn takes the form of a blue and green ribbon, colouring with the sky and the depth of the water. Its slopes, covered with a magnificent preserved primary forest, invite us to walk among palm trees with aerial roots, ferns and huge trees such as kauris, making the atmosphere of this walk fresh or overwhelming. A sanctuary for the country’s emblem With its crest deployed to intimidate, its feathers inflated, the kagu bird, with its grey plumage, walks there. Its name comes from its characteristic song which resembles the bark of a dog sounding like kagu. Rare and protected, The Big Kauri tree is said to be more than 1000 years old. It reaches 45 m in height and the diameter of its trunk 2.70 m The Giant Pots Natural cavities, hollowed out by the swirling of water and pebbles giving them an almost circular shape, they are numerous in the bed and on the banks of the Blue River, particularly in the Devil’s Horns sector. Flash floods can occur during heavy rains and make this area dangerous. ! Dotted with pots - mirrors The Great Waterfall The Giant Pots Second Devil’s Horn, crossing the Blue River on the GR®NC1 E P
The Mule Drivers’ Refuge, near the marshes Its name comes from its location near an old mule trail used by the GR® NC1 trail. Its pathswere used either by convicts formining or forestry, or by the Kanaks to pass from one valley to another and exchange with other tribes. The development of the GR® NC1 trail was based on the layout of these trails in order to minimize the environmental impact and preserve the memory of these paths with their historical and heritage character. During your walk, you may see some vestiges of this past (old stone walls, mining remains, old logs cut during logging). 35 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 34 Strolling along the waterways The White River A mysterious fragmenting hydrographic network An enigmatic circulation The White River takes many forms, sometimes narrow, sometimes wide and sometimes impetuous, at the edge of its waterfalls. Being a river with a variable flow rate due to the fact that it drains a relatively large catchment area, crossing it can be difficult or even impossible in the event of heavy rain. Winding through the plain dotted with discreet remains The Locomobile A witness to logging at the beginning of the 20th century, this boiler is the vestige of a locomotive. A huge steam winch, it was used to pull felled trees in the forest on a slope. Guided in their descent, the trees transported to the side of the track were loaded onto wagons and transported by small train to the mouth of the Pirogues River. As it travels, it develops long and meandering networks which divide then come together forming a communication between numerous ponds which shelter eels in particular. Waterfall on the White River White River Marshes Remains of rails
37 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 36 Strolling along the waterways An open, moving expanse The swamps In its meandering course, the river loses itself to form vast marshy areas covered mainly with sedges, niaouli trees, xyris and other cunoniaceae which are located at the bottom of the White River Valley. The path of the water gets lost and becomes perceptible again, gaining height. The White River, its marshes Caressed by the wind Explore the marshes of the White River “The trek is not just a question of altitude or inaccessible lands. You should also know how to enjoy a long walk around a marshy expanse whose rushes bend gently, caressed by the discreet breath of the trade wind. You have to know how to walk under the gaze of curious birds who survey their domain by describing long graceful curves in the sky.” GR®NC1, From Prony to Dumbea, Jean-Francis Clair To the West, a view over the marshes and Yaté Lake
A forest history Between 1920 and 1929, 53,000 m³ of wood, mainly kauris, were extracted throughout the Pirogues River Valley (35,000 m³) and in the Blue River Valley (18,000 m³). A 37 kilometre railway line, leading to the beautiful Month of May forest, allowed the transport of logs. The activity ceased in 1932 (Source: Chronicles of the Red Lands, the Great New Caledonian South, by Jacques Valette) 39 Direction of Sustainable Development of the South Province Territories I Strolling along the waterways 38 Strolling along the waterways The Month of May River A walk through the rainforest Running along the foothills of a ridge, the long walk of the Month of May trail, between dense humid forest, mining shrub and perspectives of wetlands, leads the walker from the Upper Valley of the Blue River to the White River. A few remains There remain few traces of the mining activity (the chrome ore extracted from the Month of May Mine was evacuated by rail to La Pirogue) and forestry activity which took place there, apart from a few paths. An intimate freshness A place full of mystery “It then penetrates into the depths of the Mont of May forest: an enigmatic space where light and shadow give the water of the creeks this very particular appearance. Branches and dead leaves crunch underfoot. The harsh smell of lush, damp earth caresses the nostrils.” GR®NC1 Guide, From Prony to Dumbea, Jean-Francis Clair Blechnum obtusatum Rainforest Swamps The marshes of the Month of May River Month of May River Bridge
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