Ecological Mangrove Rehabilitation (EMR)

EMR (Ecological Mangrove Rehabilitation) is a method to restore rehabilitation area/ site of confounding factors or by actually turn into a normal condition earlier (Lewis 1990). In mangrove ecosystems, restoration aims to improve the hydrology to natural state and increases the spread of propagule (seed distribution) and establish conditions that allow the system to be able to succeed in naturally from time to time. Species selection processBased on Chapman (1977), there are seven factors that could be determined the distribution and successful growth of mangrove, which is as follows :a. TemperatureAir and water temperatures are most likely to play a minimal role in the distribution of mangroves in Indonesia, which lies entirely within the tropics. b. Protected shorelineCoastal ecosystems are well protected from the shore supply fine sediments, deepening the substrate, greater exposure to waves and currents, etc. that affect the accumulation of sand in the mangrove growth. Degradation, deforestation, and land conversion the changing coastline will be no longer suitable for growth.c. Ocean currentsOcean currents are an important variable of mangrove distribution and thus a major factor in the biogeography of mangrove. Strong long-shore currents are not always detrimental to mangroves growth and in some cases look very good seed. The issue of global warming impacted in changing ocean currents. Changes in ocean currents are also ties to potential changes internal, which both have an impact on the resilience of mangroves.d. Substrate typeSubstrate is a variable that affects the resistance mangrove. Substrate type, volume, and resultantly high substrate in any particular location is determined by various geomorphology factors. However, the increase in sediment to the substrate due to conversion land, or natural events is intolerant to state thus accelerating the degradation of mangrove.e. ShelfShallow shelf will present a potential incident where in the event of sea level rise. The prediction is changes in the distribution of seeds that will be entered into shoreline direction, or risk of dying mangroves.f. SalinityMangroves are halophytes (both facultative and obligate) means they tolerant of salt and in some cases it seems require salinity (Rhizophora sp). In the early stages of growth the need for fresh water (like other plant species) is still needed. Salinity is one of the determining factors of zoning. Concentration and penetration of salt that continues to upstream would be effect on endurance.g. Tides and scopeThe ups and downs is not a direct physiological needs of mangrove (example: mangrove lagoon) but can be very important for most mangrove forests. The ups and downs also play an important role in ecological functions of the system, because the tidal currents into access nutrients and organic matter are transported into, through and out of the system of mangrove ecosystems.

The selection of mangrove species in coastal forest rehabilitation can also influence by another factors, which is as follows: Economical FunctionsDevelopment of economic value contain by a mangrove forest and coastal vegetation, especially the plants that were able to be developed society. This is important considering the rehabilitation activities also require the support of the community. Community aspirationsNeeds and willing of local community which has direct access and also broad community which obtain benefits but they does not own direct access toward planted areas.

SeedlingsThe planted seeds shall be moved from pot or poly bag to be placed in a hole which fits to the damage in the root area as minimum as possible. Some species of coastal forests will suffer pressure, particularly if rain is not available. Watering can be conducted after planting completed, however, it may expense some costs/time, therefore the best technique is to ensure that all planted seeds which have been watered are placed within seedling garden and to match the period of planting with rainy season. Planting Consideration According to Henley et al (2010), the plan of coastal area rehabilitation project and mangrove forests regarding the used planting pattern when seed plants ready to start must be considered before implementing. This planting pattern will depend on location condition and function selection of that forest in the future and later, it depends on the estimation of the planted trees amount. This concept can be conducted by the equation as follows:

Remark:i = amount of individualL= width of area in HaS= space between trees

As an example, space between trees of 0.5 m x 0.5 m will require 40.000 trees per hectare, meanwhile, space of 1 x 1 m will require 10.000 trees and the space of 1 x 2 m will require 5.000 trees. This space determination has an impact to the amount of required trees within certain area and besides, this space determination also according to the willing to plant trees as many as possible by adjusting the available budget of restoration program. Hydrology SystemThe most important factor to design mangrove rehabilitation project successfully is the introduction of water management system or specific hydrology (frequency and duration of tidal) within the mangrove community which is near to rehabilitation area Reference to tidal patterns and measurements, and surveys of healthy mangroves, can inform a mangrove rehabilitation model.Dredging can provide new planting material which often contains high amounts of fertilizer. Land-fill can be conducted in a necessary area, but must not create uneven terrain which could disturb the hydrology systems and disrupt mangrove growth. So its needs more assessment to sure clearly method to establish mangrove ecosystem hydrology restoration. And other forms of hydrology-focused restoration require the combination assessment of hydrology areas which are separated to the normal fresh water circulation and salty water areas explanation (Brockmeyer 1997, Turner and Lewis 1997). Standard guidelines for coastal restoration that requires its exposure limits toward waves or flows caused by the ships that passed should not be neglected (Knutson, 1981). Species of Mangrove PlantsBasically, there are levels or zonation of mangrove planting area causing species distribution variety. There are five groups of mangrove which is commonly found in beautiful mangrove forests, they are:a. Mean Sea Level MSLb. Mean High Water Neap Level MHWNc. Mean High Water Spring Level MHWSd. Between high tide line and coastal forest arease. General, one which lives in the above area but excluded by other species.According to Henley et al (2010), mangrove planting required if natural growth is impossible to occur due to lack of propagule or soil condition is not suitable. Seed planting techniques of some mangrove species is different, such as directly placement of mature Rhizopora seed within muds/fertilizer will fasten mangrove formation. This technique cant be implemented for other genre of mangrove due to seed skin extraction is previously necessary after formation completed, and also it requires roots which directly touch the surface of soil with opened cotyledons. Based on the analysis which has been conducted, the seed which are suitable to plant in northern part of Semarang by considering ecological carrying capacity are genus of Rhizophora, Avicennia and Bruguiera.a. Rhizopra mucronataGeneral description: Rhizopora mucronata is easily recognized through its standing roots and long seeds collection, various leaves which is stick out, the height is 25 m and its flowers make a group of 4-8. Seeds collection: The existing seeds which are mature and ready to pick from the trees and its yellowish branch is ready to cut, then, in this stage, the length of hypocotyl reaches more than 50 cm. Seeds storage: the seeds are stored in a shady and moist condition within 10 days for maximum. Seeds spread and planting in the pot techniques: the muddy soil is the best to be used in planting (contains salt concentration). The seeds must be planted in the depth of 10 cm by using medium to large size polybag. Covering: It requires 50% coverage, open this coverage for 1 month before planting process. Watering: Natural watering is the priority, but artificial watering is also necessary to keep humidity all the time. Ready to Plant: If the seeds are higher than 55 cm and there two pairs of leaves, it usually occurs within 4-5 months. Coastal line position: the best location is low salt concentration on the surface of muddy, between average sea water and the highest tide wave. Planting space: standing roots system needs adequate rooms, therefore the space of 1 m x 2 m and 2 m x 3 m is the best.b. Rhizophora apiculataVern name is Mangrove kacang (Ina), Bangka Minyeuk (Aceh). General Description: Rhizopora apiculata is standing roots mangrove such as R. mucronata. It has sharply edge leaves, the height is 15 m and its flowers make a group of 2. Seeds collection: The existing seeds which are mature and ready to pick from the trees and its reddish branch is ready to cut, then, in this stage, the length of hypocotyl reaches more than 20 cm. Seeds storage: the seeds are stored in a shady and moist condition within 5 days for maximum. Seeds spread and planting in the pot techniques: the muddy soil is the best to be used in planting (contains salt concentration). The seeds must be planted in the depth of 5-6 cm by using medium size polybag. Covering: It requires 50% coverage, open this coverage for 1 month before planting process. Watering: Natural watering is the priority, but artificial watering is also necessary to keep humidity all the time. Ready to Plant: If the seeds are higher than 30 cm and there two pairs of leaves, it usually occurs within 4-5 months. Coastal line position: the best location is low salt concentration on the surface of muddy, between average sea water and the highest tide wave. Planting space: standing roots system needs adequate rooms, therefore the space of 1 m x 2 m dan 2 m x 3 m is the best. c. Avicennia marina General Description: Avicennia marina has pneumatophores roots form like penciled shape, variation leaves, up to 20 m of height, small flowers and arranging groups that each group contain 8-14 flowers. Fruit likely almond, some fruit has a goblet shape on the tip, its length up to 1.5-2.5 cm. Seedling collection: mature seedling can be sign by fruit colors that has changing from green color become yellow one and going to shrink. Seedling storage: 10 days maximum storage in shaded and humid enough. Seeds spread and planting in the pot techniques: submerged fruit in fresh water during 1 day to allay place of seed. After all, spread the seeds on the soil that contain mixing of clay and sand with salinity growing factor needs enough. Seeds will growth until the roots appears, than move it into suite polybag. Covering: Avicennias seed can be grow under the direct sun light full day. Watering: Natural watering is the priority, but artificial watering is also necessary to keep humidity all the time.Ready to Plant: If the seeds are higher than 30 cm and there two pairs of leaves, it usually occurs within 3-4 months. Coastal line position: the best location is all of coastal area including high salt concentration area and grow better in high sun light intensity, as good as a pioneer plant. Planting space:, therefore the space of 1 m x 2 m and 2 m x 3 m is the best.

ECOLOGICAL MANGROVE REHABILITATION ASSESSMENT

Potential MangroveThe width of mangrove in coast area of Semarang is 84.47 Ha with Tugu District as the largest area, whereas, the width of embankment area is 1.030.21 Ha. In fact, the width of embankment in coastal area of Semarang has decreased in 2005 from 1.044.21 to 1.030.21 Ha in 2009, whereas fishery production also decreased in 2005 from 615.40 tons to 456.80 tons in 2008 (Statistics of Fishery of Semarang City in 2009). According to this condition, an effort to manage natural resources in coastal area is necessary including the development of natural resources potential within mangrove forests ecosystem in each district of Semarang City.The potential of mangrove management of each district which expected to implement the activity of coastal area community resilience to reduce the effect of climate change in Semarang City is described below.1. Mangkang Wetan Sub DistrictMangkang Wetan Sub District administratively located on the eastern of Mangunharjo Sub District of 257.052 Ha width, and 139.092 Ha for embankment landuse (Bappeda Kota Semarang, 2011). Nowadays, the major coastal area of Mangkang Wetan damaged due to abrasion affect and high flood tide and it may destroy mangrove plants and lose communities embankment area.Vegetation coverage in Mangkang Wetan Sub District is quite high. In addition, mangrove vegetation in coastal of Mangkang Wetan Sub District is dominated by Rhizopora mucronata, Avicennia marina and Sonneratia cylindrica. One place in Mangkang Wetan which becomes the central for mangrove to grow is downstream area of Bringin River which there is widely sediment stack spread of 5 Ha. This area may be flooded at sea water level get high, therefore this is potential area of planting. Salinity was high so the water became salty. Avicennia marina can grow well with high salinity. There was a deep sedimentation and muddy substrate that suitable for Rhizopora mucronata to grow. Mangkang Wetan is one sub district in Semarang City with the large of embankment of 3 Ha, therefore this potential is directly utilized by people to use this sub district as mangrove conservation land. The spread of Avicennia sp can be found in embankment belongs to Mr. Khumaidi and Mr. Fadholi which located in the edge of Bringin River. Meanwhile, the domination of Rhizopora is often found in the embankment area near to rivers and along riparian area of Bringin River, furthermore, this river provides fresh water supply and sediment to coastal area of Mangkang Wetan Sub District and Mangunharjo Sub District.Mangroves in Mangkang wetan are partially damaged. The major factors which cause the lost of mangrove affected by 3W, there are Wideng, Wedus and Wong. Wideng pest is a type of crab which often feeds mangrove seeds which has already planted. Wideng can damage the seeds of mangrove. Wedus is goat in Javanesse language. Some inhabitants have goats that wander off in this embankment area. The goats usually eat the young mangroves. Wong is human in Javanesse language. Some people have lack awareness among human being. They cut mangrove trees and utilized as fire wood and reinforce embankment.2. Mangkang KulonMangkang Kulon Sub District, Tugu District is an area located in the west of coastal area of Semarang City which functions as the border of Semarang City and Kendal Regency. The width of this sub district is 345.892 hectare with 111.165 hectare functions as embankment area (Bappeda Semarang, 2011). People use this embankment area as livelihoods by performing fish and shrimp cultivation. TPI (Location of Fish Auction) also located in this sub district, and the sellers are farmers throughout Tugu District.Abrasion and extreme sea level rise causes erosion in embankment area sediment which affects to the loss of fish and shrimp that cultivated by people and afterwards, the next effect is the lost of mangrove due to splash of waves. There was deep sedimentation and sandy substrate. The water was stagnant and no tidal. The conditions are suitable for Avicennia marina to grow.Based on EMR analysis in Mangkang Kulon sub district, there were found potential areas that can used to seed planting. On the west side of the river Mangkang in rural areas have a land area of over 105 Ha of land damaged mangrove areas putting land into ponds that are no longer productive. That area kept flooded all the time. There is no good tidal flow due to sediment that is too deep, the delay of rehabilitation interventions, and on the front side directly facing the sea that are not protected from wave energy.Mangrove in the coastal of Mangkang Kulon Sub District is dominated by Rhizopora sp and Avicennia sp of low to medium vegetation density level. The density of Avicennia sp was higher than density of Rhizopora sp. This location was once a stretch of embankment erosion eventually exposed so it turned into sandy substrate. Sandy substrate is then not match with the existing Rhizopora sp stands. Rhizopora sp eventually die from lack of nutrition. Rhizopora sp can survive live clustered in an area that still gets the supply of sediment from the river. Rhizopora sp were observed in flowered performances and generate propagules.Seedlings are often found in the beach area is kind of Rhizophora mucronata. Propagule sources Rhizopora mucronata actually quite a lot, but these propagules when falling to the ground is not germinated naturally as the dominant sandy substrate. At this location Avicennia marina seedlings were also found distributed on the riverbank. Seedlings Avicennia marina is able to germinate and grow well because sandy substrate.Various types of fauna found in mangrove area of Mangkang Kulon Sub District are heron bird, king prawn, spotted dove, grouse, water snake and wild lizard and all of them are predator for fish and shrimp that cultivated by embankment farmers, therefore those fauna disturb the farmers. Heron bird and king prawn are frequently found along Wakak River due to the existence of mangrove of Rhizopora sp in this area. Meanwhile, spotted dove and grouse are more frequently found in embankment area due to the existence of mangrove of Avicennia sp. The main activity of Kelompok Kyai Wakak II is performing cultivation in the field of embankment fishery besides they also conduct coastal conservation by planting mangrove. The group which was established in 2001 has started to plant mangrove since 2005 and 2007 from the assistance of Agricultural Office of Semarang City with the program of GERHAN/GNRLH by providing 100.000 Rhizopora mangrove seeds in 2005 and 50.000 in 2007.Today many mangrove plants which planted in 2005 and 2007 have lost due to hit by sea waves since the location of mangrove planting was along the river near to the sea which causes sea waves and winds. This condition was also found along the riparian area, many mangrove plants have lost due to hit by sea waves. 3. Mangunharjo Sub DistrictMangunharjo is the newest sub district in mangkang cluster area which has 632.802 hectares and 191.736 of landuse is for embankment area. The population is 5.590 people with 158 people are fisherman, 117 people are embankment farmers and 156 people are farmers labour. Besides conducting fish and shrimp cultivation, community in Mangunharjo Sub District also conducts coastal conservation by planting mangrove. This activity conducted by community such Lembaga Kali Santren and Biota Foundation, both organizations implementing the activity of mangrove planting. By realizing mangrove planting activity in Mangunharjo Sub District, mangrove seeds are highly needed, therefore people develop mangrove seedlings center. Mangrove which planted in Mangunharjo Sub District is more varied than other sub district in Semarang, these mangrove are Rhizopora mucronata, Rhizopora styllosa, Rhizopora apiculata, Avicennia sp and Brugueira gymnoriza.Although area distribution for mangrove planting in coastal area of Mangunharjo Sub District did not stated in written agreement between Biota Foundation and Lembaga Kali Santren, but they have already reached agreement concerning on evenly area distribution. The work area of Biota Foundation is the area near to rivers and surrounding Location of Fish Auction of Mangunharjo and the seed which commonly planted is Rhizopora sp. Meanwhile, work area of Lembaga Kali Santren is the middle part and near to the settlement and the seeds which planted are Rhizopora sp and Avicennia sp.Mangrove distribution of Avicennia sp in coastal area of Mangunharjo Sub District are more frequently found in communitys embankment which located along Plumbon River (near to the Location of Fish Auction) which its upstream comes from Wonosari Sub District, Ngaliyan District. The muddy sedimentation and low tidal was suitable for Avicennia to grow. Whereas, growth distribution of Rhizopora sp is more often found in embankment located along rivers and the middle position, in this position, mangrove trees obtain fresh water supply from Santren River which is the branch of rivers from Bringin River. Bringin River is the large river in Semarang City and may cause flood every year, particularly in the surrounding area which passed by this river that its upstream flow generated from Ngaliyan and Mijen District.Based on EMR analysis, Mangunharjo was suitable to conduct EMR because there is potential vacant area. There are some factors supporting to do EMR, 1). Temperature. Substrate temperature was warmer than air temperature. There was also low pollution. 2). Type of substrate. Substrate at the location was muddy sediment on the upper (some places indicate different depths ranging from 10 25 cm) which then contained a solid substrate consisting of a mixture of sand and soil. Sedimentation affected land and sediment erosion carried by ocean currents. 3). Ocean tides. Site location influenced the lowest tidal/ not flooded sites occur in period of 3-5 hours, while at high tide, sea water can enter up to 50 m inland (condition where the site will be inundated several moment). The EMR site position adjacent to river estuary that provided advantages in terms of hydrological flow is set in large portions by river flow.Beside the factors that support the growth in site location, there were also distractions and obstacles that include: 1). Abundance of junk mails. Site filled with household waste carried by river flow from the upstream and ocean currents. Trash sources is more caused by community careless and less awarness toward environment condition. 2). Water trapped. Variations in sediment depth, contour shape of the site, and the number of garbage at the site location that causes the hydrologic cycle disinfluencies, with some areas that were flooded sites. Water trapped is negative factor for seedling growth.Availability of seedlings this location is very good. The presence of the seawall makes Avicennia marina provide a good source for regeneration of mangroves in this location. Avicennia marina seedlings grow naturally from the tree. Seedling density Avicennia marina compose 76% of the total seedling available at this location while Rhizopora mucronata seedlings compose only 24%. Rhizopora mucronata seedlings at this location looks capable grow well characterized by an abundance of living seedlings reach 42 individu/100 m2. From the analysis of the vegetation seems to substrate conditions and physicochemical factors, as well as ecological location support the growth of mangroves. Substrate at this location dominated sand with quite deep and soft mud. Type the substrate as it is very appropriate for the growth of Rhizopora mucronata.Besides planting mangrove as described above, community groups in Mangunharjo Sub District are expected to plant other types of mangrove in the future such as Ceriops tagal, Sonneratia alba, Spinifeex sp., Casuarina equisetifoli, Achantus sp. 4. Karanganyar and Tugurejo DistrictActivity of mangrove planting in Tugurejo and Karanganyar district has been conducted since 2000. The mangrove planting is started with the planting of Rhizopora mucronata, R. styllosa and R. apiculata. Rhizopora mucronata is the dominant plant due to this type of seed is frequently found in this area. However, the activity of planting of Avicennia sp. has been conducted since in the middle year of 2009. Besides the interest of pond farmers, this type of pond will not disturb the edge of ponds and people started to plant another mangrove, namely Brugueira gymnoryza which generated from Mangrove Information Centre (MIC) Bali.The structure of mangrove planting performed by pond farmers in Tugurejo District is classified into three type of mangrove. First group: planting mixture group in coastal area, namely Rhizopora and Avicennia. Second group: estuary to the middle of middle part (parking lot to north), namely Rhizopora mucronata, R. styllosa and R. apiculata but mostly Rhizopora mucronata. Third Group: middle area to the southern (settlement), namely Avicennia sp. The coastal area has high tidal so Rhizopora mucronata will have the best growth than the other species. The middle area near settlement has low tidal that suitable for Avicennia marina to grow.Meanwhile, the mangrove vegetation in Karanganyar sub district is divided into two types of group, they are: First group: coastal to the middle area is dominated by Rhizopora mucronata. Second group: the middle part to the settlement is dominated by Avicennia sp. The tidal height level influences the distribution of mangrove. Rhizopora mucronata better survival in high tidal and Avicennia sp better survival in low tidal.Many community groups in Tugurejo Sub District which move in marine and fishery such as Kelompok Putra Samudra, Kelompok Putra Mina, Kelompok Tambak Sido Rukun, Kelompok Tabah, Kelompok Nelayan Rukun Makmur. Activities of mangrove conservation are frequently conducted by Perkumpulan Pemuda Cinta Lingkungan, Prenjak and Kelompok Putra Mina besides having partnership with other groups, those groups conducting activities of mangrove planting.Activities of mangrove planting in Tugurejo Sub District requires many seeds, therefore, community groups develop mangrove seedling center. Mangrove which planted in Tugurejo Sub District are more varied than other sub district in Semarang i.e Rhizopora mucronata, R. styllosa, R. apiculata dan Avicennia sp also not many Xylocarpus, Brugruira and Soneratia genera. However, mangrove type which mostly planted is Rhizopora mucronata. Avicennia sp and Brugueira gymnoriza are being currently developed. Area division of mangrove planting is conducted between Prenjak and Kelompok Putra Mina based on the administrative area of living and their embankment cultivation activities. Kelompok Putra Mina conducts planting in the eastern of Tugurejo, whereas, Prenjak conducts planting in the western of Tugurejo by using the seed of Rhizopora sp. and Avicennia sp.Meanwhile, activities of mangrove conservation in Karanganyar Sub District initially was conducted by Kelompok Rejo Makmur since 2007 by planting mangrove type of Rhizopora sp. However, since 2010, the activities of mangrove planting mostly conducted by fishery group of Rejomulyo and continued by Cemara Asri and Wonoku Iwaku Today, Kelompok Wonoku Iwaku chooses to develop mangrove of Avicennia sp. In addition, this selection is based on the function of Avicennia which is able to catch sedimentation, hence it is required in Karanganyar Sub District. Meanwhile, Rhizopora will be developed as additional only in soon. Its more cused by embarkment in Karanganyar condition that less mangrove barrier and fragile toward sea wave ang tidal abrasion. This type of mangrove functions as land retainer along Karanganyar River. Discussion on seedling cost was conducted by both groups from Karanganyar and Tugurejo Sub District. This discussion was started by calculating the components related to mangrove seeds including the cost of polybag plastic, planting media preparation, propagule preparation, transportation, fertilizer and maintenance.Location of mangrove seedling in Karanganyar Sub District is 300 meter square and it has been utilized since the last two years. However, there are some parts in seedling locations that should be repaired such as to add poles and cover roofs. Groups of Rhizopora planting in Karanganyar Sub District did not face any obstacles in the implementation of seedling since they have accomplished it. However, the coastal community group of Avicennia in Karanganyar Sub District still requires information and assistance. It is important to obtain seeds with high quality. Meanwhile, coastal community groups of Dukuh Tapak of Tugurejo Sub District selected to grow Avicennia sp and Sonneratia cylindrica (bogem). This selection refers to the function of Avicennia mangrove which is able to catch sediment that required in the embankment area of Tugurejo Sub District. Furthermore, Sonneratia cylindrica (bogem) functions directly as the material of syrup and foods for people since female groups in coastal area of Tapak Tugurejo have developed food processing of mangrove. Therefore, they do not need to search raw material outside if available within this area.Community groups of Dukuh Tapak, Tugurejo Sub District did not find any significant obstacles concerning with mangrove seedling implementation of Avicennia sp due to they have succeed to implement this activity during this time. However, this group does not conducted the seedling of Sonneratia sp yet, therefore, information and assistance of seedling technique are required.Community group in Dukuh Tapak Tugurejo Sub District, named Prenjak committed to mangrove conservation effort since this group has achieved the first winner of Central Java Province for environment conservationist group category in 2012 and the second winner of national level for the category of natural lovers group in 2013. According to them, the priority of mangrove conservation project in Semarang City is on mangrove ecotourism which recently land acquisition is still on progress conducted by the city government of Semarang (consultation meeting with the community held by DPKAD and Marine Office concerning of conservation land purchasing which conducted on 29 November 2013)5. Trimulyo Sub DistrictMangrove planting in coastal of Trimulyo Sub District has been conducted since 2005 by using Rhizopora mucronata which generated from local community seedling or outside. According to the discussion with Kelompok Sringi, mangrove vegetation coverage in coastal of Trimulyo Sub District is divided into three groups types of mangrove. First Group ; along Sringin River. Mangroves which grows in this area consists of Rhizopora and Avicennia sp. Avicennia is common found along Sringin river, particularly in the area which is near to settlement and factory, meanwhile, type of mangrove which exists in the southern area has mixed with Rhizopora. Second Group ; along Babon River. Mangrove of Rhizopora mucronata mostly found in this area, particularly in the area near to the estuary. Besides, mangrove association is commonly found within the space of mangrove trees. Third Group ; the eastern area of Babon River. Mangrove of Avicennia is naturally grown in this areas, the thickness of these mangrove is 30 meters from the edge of Babon River and growing outspread along + 2 km. The mangrove which grows is 45 years older than other mangrove such as Rhizopora mucronata which planted by Agricultural Office of Semarang City. Beside mangrove, hummingbird trees is other plant which grow along the body of Babon River and people utilize the flower as vegetables.Mangrove seeds which selected by Kelompok Sringin is Avicennia sp and Rhizopora sp. This selection is considered by the reason that the function of Avicennia mangrove is to catch mud or land sedimentation which is required for mangrove to grow. According to Mr. Sumadi Maskur, Avicennia sp is potential to be planted in sedimentation in the coastal area of Trimulyo. It is proven that Avicennia mangrove can be grown along Babon River of 2 km with the thickness of 30 meter. Therefore, this mangrove is potential to grow in the coastal area which is currently vulnerable toward abrasion. It is also expected that this mangrove may help to protect the embankment and settlement near to rivers and embankment. Meanwhile, mangrove of Rhizopora was selected considering that this type of mangrove functions as wave protectors. This type of mangrove will be planted by Kelompok Sringin in the edge part of Babon River which bordering with embankment and Avicennia sp will be planted inside of dike within the embankment. Mangrove seedling of Avicennia sp has never been conducted hence, technically this group requires the increase of seedling technique knowledge of mangrove Avicennia sp, whereas, kelompok Sringin often conducts Rhizopora seedling.

Mangrove nurseryNursery is one component in supporting mangrove rehabilitation. The nursery will also act as a base for community education and stewardship promotion, as the community will be engaged to manage the nursery and sell the mangrove seedlings. Because the need for seedlings goes beyond this project, there is the opportunity to generate income. The generated income then can be used to support community activities.Based on assessment for mangrove planting, four (4) nursery location has been chosen for mangrove nursery establishment i.e. Village of Mangkang Kulon, Mangkang Wetan, Tugurejo and Karanganyar. And two (2) mangrove species i.e. Bakau (Rhizophora mucronata) and Api-api (Avicennia marina.) were selected as the main species planted in the nursery along with several other selected species for species diversity enrichment purposes. 1. Mangkang KulonBased on agreement among project implementer with community group in Mangkang Kulon, Mr Sony as a leader of Kyai Wakak 2 group prepared mangrove nursery in Mangkang Kulon areas and provided 20.000 Rhizopora mucronata seeds to project supply. Kyai Wakak planed that whole seeds will be planting in Kyayi Wakak periphery. It is need approximate in 1,5 to be ready to plant. And the owner of land that used to nursery is from Semarang city 2. Mangkang Wetan The management of mangrove nursery in Mangkang Wetan is handled by Sumber Rejeki Makmur local community group that existing in Mangrove rehabilitation. The leader of this group is Mr. H. Khambali. They made 30.000 mangrove seeds to planting program with 25.000 seeds as primary seeds and the balance were as substitute and resave. From 30.000 seeds there are consisting by four (4) specieses below :Rhizopora mucronata: 10.000 seedsBrugueira gymnorhiza: 10.000 seedsAvicennia marina: 5.000 seedsSonneratia casiolaris: 5.000 seeds They consistanly to develope 4 specieses becaused it is possible to make species enrichment. All species will be planting in border between Mnagkang Wetan and Mangunharjo like in Mr. H Ali and Mr. H. Khambalis fishpond. It is also need 1,5 month to be ready to plant.3. Wonoku Iwaku 2 Group Total amount of mangrove seeds are approximately 20.000 mangrove seeds appropriate in target agreement whitout excess as replacement. Whole seeds in nursery are Avicenia marina. Because they assumed that Avicenia is the good species to catch and hold soil sediment. The location of its nursery is in local fishpond. All seeds will be planted around of nursery location because the planting location have needed more mangrove plant to make it ressiliences. 4. Prenjak Tapak GroupTotal amount of mangrove seeds are approximately 20.000 mangrove seeds appropriate in target agreement whitout excess as replacement. Total existing seeds are consisting by two species there are Rhizopora and Avicenia. All of the seeds will be distribute and planting in fishpond that needs mangrove plant enrichment.With regard to the seed type planted there will be two mangrove nursery design applied i.e. Floating Mangrove Nursery method for smaller easily float seed such as Avicennia, and method for bigger seed such as Rhizophora. The facilities should be prepared are bedengan which will continue keeping the mangrove seed and raise the seed until they are ready to plant; naungan which will protect seed from direct sunlight which will be removed when the seed are about ready to plant; and gudang which will store building, all equipment, fertilizer, etc.

Species enrichment Rhizopora and Avicenia sp., and other species seed which is potentially grown in the selected area to enrich biodiversity of the mangrove will be provided. Good quality seed is a main factor affecting the successful mangrove rehabilitation. When good quality seed are planted so successful possibility is high. Only three mangrove species has been identified as the commonly found species in the coastal area of Semarang i.e. Avicennia marina, Rhizophora mucronata and Rhizophora apiculata. Avicennia marina was mostly found as natural regeneration, while Rhizophora mucronata and Rhizophora apiculata probably were dominant as a result of artificial regeneration for years. Recent study recorded at least 8 species of true mangrove, 16 species of mangrove minor component and more than 30 species of mangrove association were exist along the northern coast of Central Java Province. Further assessment should be conducted to determine which species were most suitable to be plant to enrich mangrove biodiversity in the coastal area of Semarang.