The Mangrove Landscape and Zonation Following Soil Properties and Water Inundation Distribution in Segara Anakan Cilacap

The mangrove zoning and landscape express the correlation between mangrove vegetation ( density, biodiversity and species distribution ) with environment factors like as water inundation, seatide, and soil properties. The research was conducted in Segara Anakan Lagoon to analysis community structure and mangrove landscape based on species distribution, biodiversity, environment factors, and mangrove zoning. The results showed that ( a ) Segara Anakan Lagoon had 4 mangrove zone's were dominated by Sonneratia alba, Rhizophora mucronata, Avicennia marina, Rhizophora apiculata, Rhizophora styllosa, and Nypa frutican; ( b ) the structure of ecosystem was showed by trend of 2 mangrove ecosystem with equation y = 35.34x 923.85x + 12817 with x = time ( year ) and y = mangrove area ( ha ) , -1 -1 mangrove density between 1333367 ind ha ( West Segara Anakan ) and 899–567 ind ha ( East Segara Anakan ) , dominated species were Nypa frutican, Rhizophora stylosa, Rhizophora apiculata, and Aegiceras corniculatum and mangrove biodiversity between 2,572,65 ( moderate ) ; ( c ) structure of environment factor showed single and semi -1 double-type tides, water debit between 0.360.73 m s ; water depth between 0.20–23.7 m and water inundation -1 -1 between 480cm; soil texture was clay and loam, soil nitrate of 1.5 mg 100 g , soil phosphate of 1.5 mg 100 g , C organic of 1.31%, soil pH of 6–7, and soil salinity of 6.5–10 ppt. Abstract Segara Anakan Lagoon is a semi-closed seawater ecosystem since preserved by Nusakambangan Islands, and takes the seawater supply from the Indian Ocean and freshwater supply from many rivers like as Donan, Citanduy, Cikonde, and Sapuregel river (Hilmi et al., 2019a; 2020). This condition is a trigering factor to support potential of seatide, water inundation, pH, salinity, soil texture, and soil fertilize. The potential of soil and water factors give impact toward the mangrove zonasi and landscape in Segara Anakan Lagoon. This conditions also show the abnormal of mangrove structure and zoning in this mangrove ecosystem (Sinfuego & Buot, 2014; Datta & Deb, 2017). Basically, mangrove zonation describe a specific structure of mangrove ecosystem using variables of species disribution, species density, and environment factors. The mangrove zone and landscape are influenced by water salinity (Hoppe-Speer et al., 2011; Kantharajan et al., 2018), soil factor (Domínguez-domínguez et al., 2019), soil salinity, pH, soil fertility, water quality (Shiau et al., 2017a; Hilmi et al., 2019b), soil texture (Khadim et al., 2019), sea tide,

Mangrove ecosystem also is influenced by abnormal factors like as sedimentation and pollution. Mangrove species must have the best adaptation patterns to reduce high sedimentation and pollution in Segara Anakan Lagoon. The specific adaptation of mangrove species also are developed to reduce impact of mangrove degradation (Ferreira et al., 2015;Kantharajan et al., 2018), sedimentation (Sari et al., 2016), pollution, and minor species expansion (Smee et al., 2017). Based on the data of several research show that in Segara Anakan Lagoon (SAL) has high sedimentation (sediment -1 rate between 4.26103.60 g day and total sedimentation -1 0.228.05 million ton year ) (Sari et al., 2016), mixed semi--1 diurnal tide, seawater current (0.360.73 m s ), inundation level (076 cm), water salinity (30.9934.01 ppt) and pH (6.767.02) (Sari et al., 2016;Hilmi et al., 2019b) and be dominated species by Rhizophora spp., Avicennia spp., and Nypa frutican. The mangrove landscape and zonation following soil properties and water inundation distribution in Segara Anakan Cilacap is develop by relation among species distribution, biodiversity, mangrove density with environment factors. This paper aimed to analysis mangrove landscape and zone's using mangrove density, mangrove covering, mangrove adaptation and distribution soil properties, oceanography and water quality as main variables.

Soil water factor analysis
The analysis of soil water were (a) soil water salinity (ppt) using the conductive-photometric method/Hand Refractometer, (b) soil pH using Potentiometric method/pH meter (APHA, 2005;; (c) Research area This research was conducted in Segara Anakan Lagoon (SAL) which was arranged by the mangrove, river (Donan River, Sapuregel River, Kembang Kuning River, Citanduy River, Cimeneng River, and Cikonde River), terrestrial and estuary ecosystems (Hilmi et al., 2019a;2019b), and Nusakambangan Island as perserved area. This research collect data on 37 stations that were 17 stations in Esat Segara Anakan Lagoon/E-SAL which were distributed in Kalipanas, Donan River, Sapuregel, Pelawangan Timur, and Kembang Kuning River, and 20 stations in West Segara Anakan Lagoon/W-SAL were distributed in Ujung Gagak, Majingklak, Klaces, Ujung Alang, and Kali Semak (Table 1 and Figure 1). The research in SAL was conducted between 2019-2021 to analysis mangrove density, soil water, sea tide, and sea water inundation. Seatide, currrent speed and seawater inundation Seatide analysis used tidal data of Navigation District Class III Cilacap. The data were first processed using Microsoft Excel with Admiralty tidal behavior calculation method; Current speed used water column current speed measurement with AEM213-D electro-magnetic current meter instrument; Water depth used water column depth measurement method with 2 instruments consisting of multi-beam echo sounder and tin pendulum (dreadloading); and Water inundation (cm) analysis used the tide and inundation stick method to record inundation and tidal scale of stick.  Table 2).

The data analysis
The mangrove zoning The mangrove distribution was showed by the mangrove covering, the species density, the biodiversity and diameter distribution. The mangrove distribution describe the potential area and species of mangrove ecosystem in Segara Anakan Lagoon. The mangrove distribution also showed domination species of mangrove ecosystem in Segara Anakan Lagoon.

Mangrove landscape analysis
The mangrove landscape analysis was used to describe species distribution of mangrove ecosystem in Segara Anakan Lagoon Cilacap. The mangrove landscape was build using the correlation analysis among species density with water depth level (cm), water inundation (cm), pH, and salinity.

Results and Discussion
Biodiversity analysis The mangrove biodiversity divided 3 analysis that were species richness, heterogeneity, and evenness index. The mangrove biodiversity analysis used Margaleff index (to analysis species richness), Shannon Wiener index (to analysis heterogenity), and Evennes index (Magurran, 1996). The data on Figure 2 and Figure 3 expressed the fast rate of mangrove destruction in Segara Anakan. The prediction model using best regression model and linier model predicted that potential of mangrove ecostystem in Segara Anakan Lagoon ≤ 5,174,6 ha and potential lagoon ≤ 950.5 ha. Xin et al. (2014) also gives note that more than 1/3 total area of mangrove in India, Indonesia, Sri Lanka, Thailand, and China were degraded. The mangrove and lagoon degradation in Segara Anakan Lagoon were caused by conversions to fishponds, settlements and industries, ilegal logging, expansion of Acanthus (Ardli & Wolff, 2008), sedimentation (Sari et al., 2016), waste pollution disposal and hydrocarbon (Hidayati et al., 2011;Syakti et al., 2013a;2013b), and accretion . Singh et al. (2013), Victor et al. (2006), and Schwarzer et al. (2016) also estimate the degradation of mangrove ecosystem is caused by conversion, illegal logging, sedimentation, and water pollution including heavy metal pollution The mangrove density The structure of mangrove density was expressed by mangrove species density and mangrove area. The density of mangrove area was showed by Figure 4 and Table 2. The data showed that potential mangrove density in Segara Anakan Lagoon divided (a) East Segara  The mangrove density and species distribution in SAL could be shown on Table 2. The data explain that mangrove density in E-SAL more dense than W-SAL. The mangrove ecosystem in E-SAL was dominated by high density and very high denity (70.6%), whereas W-SAL is dominated by rare density (55.0%). The species dominant in SAL were Sonneratia alba, R. mucronata, A. marina, R. apiculata, R. styllosa, and N. frutican.
The distribution of species density in mangrove ecosystem SAL could be shown on Figure 6. The data on Figure 6 showed that the highest distribution of species density in W-SAL were N. frutican, A. alba, A. marina, and S. However, the species density of mangrove ecosystem in SAL could be shown on Figure 5. The data showed that E- -1 1493 trees ha . Potential density of mangrove ecosystem in E-SAL more than mangrove ecosystem in W-SAL. The indicators of mangrove degaradation are showed by the narrowing area of lagoon, loosing of organism habitats, expansion of Acanthus spp., and Acrossticum aureum (Hilmi et al., 2019a;2020). The others impact are decreasing of fisherman incomes, aquaculture productivity, distrubed transportation, death of organsim aquatic, and othres.
The trigerring factors of mangrove zone Sea tide, water depth and water current The lagoon ecosystem in Segara Anakan had the semi diurnal until mixed prevailing semidiurnal of sea tides (in Eastern SAL) and mixed prevailing semi-diurnal of sea tides (in Western SAL), water debit or -1 current speed of between 0.210.87 m s and water depth of between 0.24-20.17 m (Table 5 and Figure 7). The research of Anthony (2004) notes that the river debit data of more -1 than 0.2 m s which is not different with that of Segara Anakan.

Mangrove diversity and diameter distribution
The last indicator of community structure is the mangrove diversity and diameter distribution will be shown on Table 3. Based on the mangrove diversity showed that Segara Anakan Cilacap had moderate diversity both of species richness and heterogenity but had homogen distribution. However, based on diameter distribution showed that mangrove ecosystem in Segara Anakan had highest diameter distribution between 0-10 cm ( Table 4).
The first indicator is the sea tide types. Based on the Formzahl value, Segara Anakan Lagoon has semi diurnal to mixed prevailing semi-diurnal tide with different (asymmetric) shapes between the first and the second tide. The data range between 10403 cm (sea tide) and 30157 cm (MSL). This condition caused the river and tidal debit still 0.210.8 ms and the lagoon optimum water depth of < 23.76 m. The data were lower than the potential river debit in Cocoa ck (Aucan & Ridd, 2000). This condition was caused by the existence of Nusakambangan Island as a buffer of SAL from sea current and wind current. This data showed that Segara Anakan Lagoon is the semi closed hydrodynamic of water current and river debits which is influenced by the interaction among river debit, tidal wave, mangrove ecosystem, sediment distribution, and waste disposal Suhendra et al., 2018). Table 3 also showed the river current and river debit in Segara -1 Anakan Lagoon ranging of between 0.340.75 m s .

Distribution of soil factors Segara Anakan
Lagoon had dominated soil texture was clay and loam; nitrate distribution of between 0.1280.191%, phosphate of between 9.5614.95%, C-organic ranging between 1.161.49%; pH of between 5.737,53 and water salinity of between 13.519.5 ppt (E-SAL) and nitrate distribution of between 0.0780.133%, phosphate of between 10.4413.77%, C-organic ranging between 1.161.47%; pH of between 6.207.53, and water salinity of between 13.519.5 ppt (W-SAL) ( Table 5).
The data showed that (1) C-organic in W-SAL similar value with E-SAL, (2) potential pH in W-SAL higher than E-SAL, (3) nitrate potential in W-SAL less than E-SAL, (4) water salinity in W-SAL less than E-SAL, and (5) phosphate potential in W-SAL higher than E-SAL.   The relation among mangrove zone and landscape with trigerring factors The correlation between mangrove density with trigerring factors showed that dissolve oxygen, water pH, sea tide and soil salinity had moderate correlation with mangrove density (Table 6). According to Kusmana & Maulina (2015), Nelson et al. (2009), and, soil texture and soil salinity have big impact for mangrove distribution and landscape.
The second indicator is the river current and water depth. -1 The potential river current between 0.210.8 m s and the lagoon optimum water depth of < 23.76 m is very suitable condition to support mangrove live. Cahyo, (2012) also writes that the W-SAL has current and river debits 0,6768 m -1 s with direction 240,1 (southwest) (low tide) and 0,1578 m s 1 with direction 8,3 (north) (high tide).
Base on data of sea tide, water depth, water current and soil factors in Segara Anakan Lagoon showing the suitable habitat to support mangrove growth. The suitable habitat of mangrove in SAL are shown by the first indicator seatide. Seatide in Segara Anakan semi diurnal to mixed prevailing semi-diurnal tide with data range between 10403 cm (sea tide) and 30157 cm (MSL). The seatide condition is very suitable to support mangrove growth (Mazda et al., 2007;Hilmi et al., 2015).
The last indicators are distribution of soil factors. Soil factors like as soil salinity, pH, and soil texture have high influence to develop the species distribution in mangrove ecosystem (Castillo et al., 2017;Datta & Deb, 2017). Kusmana and Maulina (2015) stated salinity as first soil indicator is a big factor to influence mangrove distribution, because salinity causes disseminating mangrove plants, canopy opening, species distribution, species density, species composition and inhibiting nitrogen assimilation, and mangrove plants grow well with the salinity of 1030 ppt. The second factor is soil pH. The soil pH in Segara Anakan Lagoon had ranges between 5.796.27 (acid-neutral). Hilmi et al. (2019a) stated that mangrove grows well on pH of between 68.5. Then, the other soil properties are Nitrate, Phosphate and C-organic. These data showed that Segara Anakan had high soil fertility to support the mangrove growth (Xiong et al., 2018), because SAL had the nitrate of between 0.110.33% (highly potential); phosphate of between 9.4713.8% (highly potential) and C-organic of between 1.151.48%.

Recommendation
The mangrove landscape uses several indictors of environment factors, mangrove density and species distribution can be used to support mangrove rehabilitation program. The mangrove landscape also is used to support mangrove dynamic activity and to draw mangrove adaptation in the mangrove ecosystem.